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One year after hospitalization for COVID-19 only a minority of people feel fully recovered, with being female, obesity, and having had mechanical ventilation in hospital risk factors for not feeling fully recovered.

In the new U.K. study of more than 2,000 patients, presented at this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID 2022), and published in The Lancet Respiratory Medicine, research showed that one in four patients feel fully well again 1 year after hospitalization for COVID-19.

For their study, researchers from the University of Leicester used data from the post-hospitalization COVID-19 (PHOSP-COVID) prospective, longitudinal cohort study, which assessed adults aged 18 years and over who had been hospitalized with COVID-19 across the United Kingdom and subsequently discharged. The researchers assessed the recovery of 2,320 participants discharged from 39 U.K. hospitals between March 7, 2020, and April 18, 2021, who were assessed via patient-reported outcome measures, physical performance, and organ function at 5 months and at 1 year after hospital discharge. Blood samples were taken at the 5-month visit to be analyzed for the presence of various inflammatory proteins.

All participants were assessed at 5 months after discharge and 807 participants (33%) completed both the 5-month and 1-year visits at the time of the analysis. The study is ongoing. The 807 patients were mean age of 59 years, 36% were women, and 28% received invasive mechanical ventilation. The proportion of patients reporting full recovery was similar between 5 months (26%) and 1 year (29%).
 

Female sex and obesity major risk factors for not recovering

Being female, obese, and having had mechanical ventilation in hospital makes someone 32%, 50%, and 58%, respectively, less likely to feel fully recovered 1 year after COVID-19 hospitalization, the authors said.

“We found female sex and obesity were major risk factors for not recovering at one year,” said the researchers, led by Rachael Evans, PhD, Louise V. Wain, and Christopher E. Brightling, PhD, National Institute for Health Research, Leicester Biomedical Research Centre, University of Leicester.

The authors said fatigue, muscle pain, physically slowing down, poor sleep, and breathlessness were most common ongoing long COVID symptoms. They noted how the total number and range of ongoing symptoms at 1 year was “striking,” positively associated with the severity of long COVID, and emphasizes the “multisystem nature of long COVID.”
 

Several inflammatory mediators increased

An earlier publication from this study identified four groups or “clusters” of symptom severity at 5 months, which were confirmed by this new study at 1 year, the authors said. They reported that 20% had very severe physical and mental health impairment, 30% had severe physical and mental health impairment, 11% had moderate physical health impairment with cognitive impairment, and 39% had mild mental and physical health impairment.

They added that having obesity, reduced exercise capacity, a greater number of symptoms, and increased levels of C-reactive protein were associated with the “more severe clusters.” In both the very severe and the moderate with cognitive impairment clusters, levels of interleukin-6 (IL-6) were higher when compared with the mild cluster.

“The limited recovery from 5 months to 1 year after hospitalisation in our study across symptoms, mental health, exercise capacity, organ impairment, and quality-of-life is striking,” the researchers noted.

“In our clusters, female sex and obesity were also associated with more severe ongoing health impairments including reduced exercise performance and health-related quality of life at one year,” and suggested that this potentially highlighted a group that “might need higher intensity interventions such as supervised rehabilitation,” they added.

There are no specific therapeutics for long COVID, the researchers said, noting that “effective interventions are urgently required.” The persistent systemic inflammation identified, particularly in those in the very severe and moderate with cognitive impairment clusters, suggested that these groups “might respond to anti-inflammatory strategies,” the authors wrote.

“We found that a minority of participants felt fully recovered 1 year after hospital discharge, with minimal improvement after a 5-month assessment,” they noted.

They added that the findings suggest the need for complex interventions that target both physical and mental health impairments to alleviate symptoms, and that specific therapeutic approaches to manage posttraumatic stress disorder might also be needed. The authors pointed out how “pharmacological and non-pharmacological interventions are urgently needed,” with a “precision-medicine approach with potential treatable traits of systemic inflammation and obesity.”

They said their study highlighted the “urgent need for health-care services to support the large and rapidly increasing patient population in whom a substantial burden of symptoms exist, including reduced exercise capacity and substantially decreased health-related quality of life one year after hospital discharge.”

They warned that without effective treatments, long COVID could become a “highly prevalent new long-term condition.”

A version of this article first appeared on Medscape UK.

One year after hospitalization for COVID-19 only a minority of people feel fully recovered, with being female, obesity, and having had mechanical ventilation in hospital risk factors for not feeling fully recovered.

In the new U.K. study of more than 2,000 patients, presented at this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID 2022), and published in The Lancet Respiratory Medicine, research showed that one in four patients feel fully well again 1 year after hospitalization for COVID-19.

For their study, researchers from the University of Leicester used data from the post-hospitalization COVID-19 (PHOSP-COVID) prospective, longitudinal cohort study, which assessed adults aged 18 years and over who had been hospitalized with COVID-19 across the United Kingdom and subsequently discharged. The researchers assessed the recovery of 2,320 participants discharged from 39 U.K. hospitals between March 7, 2020, and April 18, 2021, who were assessed via patient-reported outcome measures, physical performance, and organ function at 5 months and at 1 year after hospital discharge. Blood samples were taken at the 5-month visit to be analyzed for the presence of various inflammatory proteins.

All participants were assessed at 5 months after discharge and 807 participants (33%) completed both the 5-month and 1-year visits at the time of the analysis. The study is ongoing. The 807 patients were mean age of 59 years, 36% were women, and 28% received invasive mechanical ventilation. The proportion of patients reporting full recovery was similar between 5 months (26%) and 1 year (29%).
 

Female sex and obesity major risk factors for not recovering

Being female, obese, and having had mechanical ventilation in hospital makes someone 32%, 50%, and 58%, respectively, less likely to feel fully recovered 1 year after COVID-19 hospitalization, the authors said.

“We found female sex and obesity were major risk factors for not recovering at one year,” said the researchers, led by Rachael Evans, PhD, Louise V. Wain, and Christopher E. Brightling, PhD, National Institute for Health Research, Leicester Biomedical Research Centre, University of Leicester.

The authors said fatigue, muscle pain, physically slowing down, poor sleep, and breathlessness were most common ongoing long COVID symptoms. They noted how the total number and range of ongoing symptoms at 1 year was “striking,” positively associated with the severity of long COVID, and emphasizes the “multisystem nature of long COVID.”
 

Several inflammatory mediators increased

An earlier publication from this study identified four groups or “clusters” of symptom severity at 5 months, which were confirmed by this new study at 1 year, the authors said. They reported that 20% had very severe physical and mental health impairment, 30% had severe physical and mental health impairment, 11% had moderate physical health impairment with cognitive impairment, and 39% had mild mental and physical health impairment.

They added that having obesity, reduced exercise capacity, a greater number of symptoms, and increased levels of C-reactive protein were associated with the “more severe clusters.” In both the very severe and the moderate with cognitive impairment clusters, levels of interleukin-6 (IL-6) were higher when compared with the mild cluster.

“The limited recovery from 5 months to 1 year after hospitalisation in our study across symptoms, mental health, exercise capacity, organ impairment, and quality-of-life is striking,” the researchers noted.

“In our clusters, female sex and obesity were also associated with more severe ongoing health impairments including reduced exercise performance and health-related quality of life at one year,” and suggested that this potentially highlighted a group that “might need higher intensity interventions such as supervised rehabilitation,” they added.

There are no specific therapeutics for long COVID, the researchers said, noting that “effective interventions are urgently required.” The persistent systemic inflammation identified, particularly in those in the very severe and moderate with cognitive impairment clusters, suggested that these groups “might respond to anti-inflammatory strategies,” the authors wrote.

“We found that a minority of participants felt fully recovered 1 year after hospital discharge, with minimal improvement after a 5-month assessment,” they noted.

They added that the findings suggest the need for complex interventions that target both physical and mental health impairments to alleviate symptoms, and that specific therapeutic approaches to manage posttraumatic stress disorder might also be needed. The authors pointed out how “pharmacological and non-pharmacological interventions are urgently needed,” with a “precision-medicine approach with potential treatable traits of systemic inflammation and obesity.”

They said their study highlighted the “urgent need for health-care services to support the large and rapidly increasing patient population in whom a substantial burden of symptoms exist, including reduced exercise capacity and substantially decreased health-related quality of life one year after hospital discharge.”

They warned that without effective treatments, long COVID could become a “highly prevalent new long-term condition.”

A version of this article first appeared on Medscape UK.

One year after hospitalization for COVID-19 only a minority of people feel fully recovered, with being female, obesity, and having had mechanical ventilation in hospital risk factors for not feeling fully recovered.

In the new U.K. study of more than 2,000 patients, presented at this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID 2022), and published in The Lancet Respiratory Medicine, research showed that one in four patients feel fully well again 1 year after hospitalization for COVID-19.

For their study, researchers from the University of Leicester used data from the post-hospitalization COVID-19 (PHOSP-COVID) prospective, longitudinal cohort study, which assessed adults aged 18 years and over who had been hospitalized with COVID-19 across the United Kingdom and subsequently discharged. The researchers assessed the recovery of 2,320 participants discharged from 39 U.K. hospitals between March 7, 2020, and April 18, 2021, who were assessed via patient-reported outcome measures, physical performance, and organ function at 5 months and at 1 year after hospital discharge. Blood samples were taken at the 5-month visit to be analyzed for the presence of various inflammatory proteins.

All participants were assessed at 5 months after discharge and 807 participants (33%) completed both the 5-month and 1-year visits at the time of the analysis. The study is ongoing. The 807 patients were mean age of 59 years, 36% were women, and 28% received invasive mechanical ventilation. The proportion of patients reporting full recovery was similar between 5 months (26%) and 1 year (29%).
 

Female sex and obesity major risk factors for not recovering

Being female, obese, and having had mechanical ventilation in hospital makes someone 32%, 50%, and 58%, respectively, less likely to feel fully recovered 1 year after COVID-19 hospitalization, the authors said.

“We found female sex and obesity were major risk factors for not recovering at one year,” said the researchers, led by Rachael Evans, PhD, Louise V. Wain, and Christopher E. Brightling, PhD, National Institute for Health Research, Leicester Biomedical Research Centre, University of Leicester.

The authors said fatigue, muscle pain, physically slowing down, poor sleep, and breathlessness were most common ongoing long COVID symptoms. They noted how the total number and range of ongoing symptoms at 1 year was “striking,” positively associated with the severity of long COVID, and emphasizes the “multisystem nature of long COVID.”
 

Several inflammatory mediators increased

An earlier publication from this study identified four groups or “clusters” of symptom severity at 5 months, which were confirmed by this new study at 1 year, the authors said. They reported that 20% had very severe physical and mental health impairment, 30% had severe physical and mental health impairment, 11% had moderate physical health impairment with cognitive impairment, and 39% had mild mental and physical health impairment.

They added that having obesity, reduced exercise capacity, a greater number of symptoms, and increased levels of C-reactive protein were associated with the “more severe clusters.” In both the very severe and the moderate with cognitive impairment clusters, levels of interleukin-6 (IL-6) were higher when compared with the mild cluster.

“The limited recovery from 5 months to 1 year after hospitalisation in our study across symptoms, mental health, exercise capacity, organ impairment, and quality-of-life is striking,” the researchers noted.

“In our clusters, female sex and obesity were also associated with more severe ongoing health impairments including reduced exercise performance and health-related quality of life at one year,” and suggested that this potentially highlighted a group that “might need higher intensity interventions such as supervised rehabilitation,” they added.

There are no specific therapeutics for long COVID, the researchers said, noting that “effective interventions are urgently required.” The persistent systemic inflammation identified, particularly in those in the very severe and moderate with cognitive impairment clusters, suggested that these groups “might respond to anti-inflammatory strategies,” the authors wrote.

“We found that a minority of participants felt fully recovered 1 year after hospital discharge, with minimal improvement after a 5-month assessment,” they noted.

They added that the findings suggest the need for complex interventions that target both physical and mental health impairments to alleviate symptoms, and that specific therapeutic approaches to manage posttraumatic stress disorder might also be needed. The authors pointed out how “pharmacological and non-pharmacological interventions are urgently needed,” with a “precision-medicine approach with potential treatable traits of systemic inflammation and obesity.”

They said their study highlighted the “urgent need for health-care services to support the large and rapidly increasing patient population in whom a substantial burden of symptoms exist, including reduced exercise capacity and substantially decreased health-related quality of life one year after hospital discharge.”

They warned that without effective treatments, long COVID could become a “highly prevalent new long-term condition.”

A version of this article first appeared on Medscape UK.

Political elections can be hard on the heart, suggests a study that showed a substantial uptick in hospital admissions for acute cardiovascular conditions immediately after the 2020 American presidential election.

The analysis of nearly 6.4 million adults showed that the rate of hospitalization for acute cardiovascular disease (CVD) was 17% higher in the 5 days after the election than in a 5-day period 2 weeks earlier.

The rate of acute myocardial infarction (AMI) was 42% higher, with no significant difference for heart failure or stroke hospital admissions.

“These findings suggest that awareness of the heightened risk of CVD and strategies to mitigate risk during notable political events are needed,” write Matthew T. Mefford, PhD, of Kaiser Permanente Southern California, Pasadena, and colleagues.

The study was published in the April issue of JAMA Network Open.
 

Stress and the heart

In the American Psychological Association Stress in America 2020 survey conducted roughly 3 months before the 2020 presidential election, 77% of adults cited the future of the country as a substantial source of stress, enhanced by the ongoing COVID-19 pandemic, the authors note. More than two-thirds said the election was a substantial source of stress.

Dr. Mefford and colleagues compared CVD hospitalizations at Kaiser Permanente Southern and Northern California hospitals in the 5-day risk window of Nov. 4-8, 2020, with the control window of Oct. 21-25, 2020.

There were 666 CVD hospitalizations (760.47 per 100,000 person-years [PY]) in the risk window, compared with 569 (647.97 per 100,000 PY) in the control window (rate ratio, 1.17; 95% confidence interval, 1.05-1.31).

There were also significantly more hospitalizations for AMI immediately after the election than before (179 vs. 126 AMI hospitalizations; 204.4 vs. 143.5 per 100,000 PY; RR, 1.42; 95% CI, 1.13-1.79).

There was no significant difference between the risk and control periods for hospitalizations because of stroke or heart failure.

The study also suggests higher rates of acute CVD after the election in older adults, men, and White individuals. Political affiliation was not examined in the study.

“Importantly, results were consistent before and after excluding patients with confirmed COVID-19 infection,” the study team notes.

Yet, the potential influence of COVID-19 stressors on increasing CVD risk cannot be ruled out, they say.

However, COVID-19 stressors occurred over a much longer period and are less likely to explain the transient risks observed in the defined risk and control windows that are in close proximity to the 2020 election, the investigators point out.

There is growing evidence that psychological health contributes to CVD.

Previous studies shown a higher risk for acute CVD around population-wide psychosocial or environmental stressors, but less was known about acute CVD risk in relation to political events.

The researchers note future studies evaluating stress-relieving interventions may be important for understanding the intersection of political events, associated stress, and acute CVD risk.

Partial funding for the study was provided by a grant from the W.K. Kellogg Foundation. The authors have no relevant conflicts of interest.

A version of this article first appeared on Medscape.com.

Political elections can be hard on the heart, suggests a study that showed a substantial uptick in hospital admissions for acute cardiovascular conditions immediately after the 2020 American presidential election.

The analysis of nearly 6.4 million adults showed that the rate of hospitalization for acute cardiovascular disease (CVD) was 17% higher in the 5 days after the election than in a 5-day period 2 weeks earlier.

The rate of acute myocardial infarction (AMI) was 42% higher, with no significant difference for heart failure or stroke hospital admissions.

“These findings suggest that awareness of the heightened risk of CVD and strategies to mitigate risk during notable political events are needed,” write Matthew T. Mefford, PhD, of Kaiser Permanente Southern California, Pasadena, and colleagues.

The study was published in the April issue of JAMA Network Open.
 

Stress and the heart

In the American Psychological Association Stress in America 2020 survey conducted roughly 3 months before the 2020 presidential election, 77% of adults cited the future of the country as a substantial source of stress, enhanced by the ongoing COVID-19 pandemic, the authors note. More than two-thirds said the election was a substantial source of stress.

Dr. Mefford and colleagues compared CVD hospitalizations at Kaiser Permanente Southern and Northern California hospitals in the 5-day risk window of Nov. 4-8, 2020, with the control window of Oct. 21-25, 2020.

There were 666 CVD hospitalizations (760.47 per 100,000 person-years [PY]) in the risk window, compared with 569 (647.97 per 100,000 PY) in the control window (rate ratio, 1.17; 95% confidence interval, 1.05-1.31).

There were also significantly more hospitalizations for AMI immediately after the election than before (179 vs. 126 AMI hospitalizations; 204.4 vs. 143.5 per 100,000 PY; RR, 1.42; 95% CI, 1.13-1.79).

There was no significant difference between the risk and control periods for hospitalizations because of stroke or heart failure.

The study also suggests higher rates of acute CVD after the election in older adults, men, and White individuals. Political affiliation was not examined in the study.

“Importantly, results were consistent before and after excluding patients with confirmed COVID-19 infection,” the study team notes.

Yet, the potential influence of COVID-19 stressors on increasing CVD risk cannot be ruled out, they say.

However, COVID-19 stressors occurred over a much longer period and are less likely to explain the transient risks observed in the defined risk and control windows that are in close proximity to the 2020 election, the investigators point out.

There is growing evidence that psychological health contributes to CVD.

Previous studies shown a higher risk for acute CVD around population-wide psychosocial or environmental stressors, but less was known about acute CVD risk in relation to political events.

The researchers note future studies evaluating stress-relieving interventions may be important for understanding the intersection of political events, associated stress, and acute CVD risk.

Partial funding for the study was provided by a grant from the W.K. Kellogg Foundation. The authors have no relevant conflicts of interest.

A version of this article first appeared on Medscape.com.

Political elections can be hard on the heart, suggests a study that showed a substantial uptick in hospital admissions for acute cardiovascular conditions immediately after the 2020 American presidential election.

The analysis of nearly 6.4 million adults showed that the rate of hospitalization for acute cardiovascular disease (CVD) was 17% higher in the 5 days after the election than in a 5-day period 2 weeks earlier.

The rate of acute myocardial infarction (AMI) was 42% higher, with no significant difference for heart failure or stroke hospital admissions.

“These findings suggest that awareness of the heightened risk of CVD and strategies to mitigate risk during notable political events are needed,” write Matthew T. Mefford, PhD, of Kaiser Permanente Southern California, Pasadena, and colleagues.

The study was published in the April issue of JAMA Network Open.
 

Stress and the heart

In the American Psychological Association Stress in America 2020 survey conducted roughly 3 months before the 2020 presidential election, 77% of adults cited the future of the country as a substantial source of stress, enhanced by the ongoing COVID-19 pandemic, the authors note. More than two-thirds said the election was a substantial source of stress.

Dr. Mefford and colleagues compared CVD hospitalizations at Kaiser Permanente Southern and Northern California hospitals in the 5-day risk window of Nov. 4-8, 2020, with the control window of Oct. 21-25, 2020.

There were 666 CVD hospitalizations (760.47 per 100,000 person-years [PY]) in the risk window, compared with 569 (647.97 per 100,000 PY) in the control window (rate ratio, 1.17; 95% confidence interval, 1.05-1.31).

There were also significantly more hospitalizations for AMI immediately after the election than before (179 vs. 126 AMI hospitalizations; 204.4 vs. 143.5 per 100,000 PY; RR, 1.42; 95% CI, 1.13-1.79).

There was no significant difference between the risk and control periods for hospitalizations because of stroke or heart failure.

The study also suggests higher rates of acute CVD after the election in older adults, men, and White individuals. Political affiliation was not examined in the study.

“Importantly, results were consistent before and after excluding patients with confirmed COVID-19 infection,” the study team notes.

Yet, the potential influence of COVID-19 stressors on increasing CVD risk cannot be ruled out, they say.

However, COVID-19 stressors occurred over a much longer period and are less likely to explain the transient risks observed in the defined risk and control windows that are in close proximity to the 2020 election, the investigators point out.

There is growing evidence that psychological health contributes to CVD.

Previous studies shown a higher risk for acute CVD around population-wide psychosocial or environmental stressors, but less was known about acute CVD risk in relation to political events.

The researchers note future studies evaluating stress-relieving interventions may be important for understanding the intersection of political events, associated stress, and acute CVD risk.

Partial funding for the study was provided by a grant from the W.K. Kellogg Foundation. The authors have no relevant conflicts of interest.

A version of this article first appeared on Medscape.com.

An overall ninefold increase in COVID-19 antibody levels can be seen with a longer interval between first and second doses of the Pfizer/BioNTech (BNT162b2) vaccine in people without prior infection, according to data from the U.K. government’s SIREN (SARS-CoV-2 Immunity and Reinfection Evaluation) study.

This interval-dependent antibody level varied by age, with those aged 45-54 years showing an 11-fold increase with a longer dosing interval (greater than 10 weeks vs. 2-4 weeks). People younger than age 25 years showed a 13-fold increase with the longer interval, but participant numbers were low in this sub-group.

Overall antibody levels in infection-naive participants were 1,268.72 Binding Antibody Units (BAU)/mL (1,043.25-1,542.91) in those with a 2-4–week interval, compared with 11,479.73 BAU/mL (10,742.78-12,267.24) (P < .0001), in those with at least a 10-week interval between doses.

The work is the latest analysis from SIREN, which measured antibody levels in the blood from nearly 6,000 health care workers from across the United Kingdom. Study lead Ashley Otter, PhD, technical lead for SIREN serology at the UK Health Security Agency (UKHSA), will present the work on Tuesday at the 2022 European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), Lisbon.

In an interview, Dr. Otter noted that, “it is important to remember that antibody levels are only one aspect of the immune response, and in our recent vaccine effectiveness analysis, we found that dosing intervals did not affect protection against infection.”

The study, which appeared in the March issue of the New England Journal of Medicine, also found that after the second dose of vaccine, there was about a 2.5–fold difference in antibody levels between those who had prior infection of 16.052 (14.071-18.312) BAU/mL, compared with 7.050 (6.634-7.491) BAU/mL in infection-naive individuals (P < .0001).

Following the first dose only, antibody levels were up to 10 times higher in participants who were previously infected, compared with infection-naive individuals. This effect lasted up to 8 months and then began to plateau.
 

Natural infection increased antibody levels

Dr. Otter remarked that, “COVID-19 antibody levels are high in those people who were previously naturally infected and vaccinated, highlighting that vaccination provides an additional benefit to these individuals.”

This news organization asked Charlotte Thålin, PhD, an immunologist from the Karolinska Institute, Stockholm, to comment on the study. Dr. Thålin studies a cohort similar to SIREN, called the Swedish COMMUNITY health care worker cohort. “The new data from the SIREN emphasizes the importance of the number of antigenic exposures and the time interval between them, whether it be exposure through vaccination or exposure through infection.” 

“We see similar data in our Swedish COMMUNITY health care worker cohort,” Dr. Thålin continued, “where infection prior to vaccination yields a more than twofold enhancement in antibodies, neutralizing breadth, and T cell responses, and an even larger increase with a longer time interval between infection and vaccination.”

However, she cautioned that they now see a high rate of Omicron vaccine breakthrough infections, and this is also true in people with previous infection and three vaccine doses.

“As we approach a second booster – a fourth vaccine dose – we need to consider that many individuals will have had up to five to six antigen exposures within a short period of time, sometimes within a year,” she pointed out. “This is a whole new scenario, with a lot of different combinations of vaccine and infection-induced immunity. We do not yet know the impact of these frequent immune exposures, and we now need to monitor immune responses following Omicron and booster doses closely.”

SIREN originally aimed to understand how much protection people got after developing a primary infection and why they might become reinfected with COVID-19. Following the rollout of the United Kingdom’s vaccination program, the protective effects of vaccination against COVID-19 were investigated, as well as why some people still become ill after being vaccinated, Dr. Otter explained.

In this latest analysis, Dr. Otter and colleagues assessed anti-spike binding antibodies in serum samples from a total of 5,871 health care workers, with 3,989 after one dose (at least 21 days) and 1,882 after two doses (at least 14 days).

Most participants were women (82.3%), of White ethnicity (87%), and came from across the United Kingdom.

Participants were also categorized into those who had evidence of natural COVID-19 infection (confirmed by a PCR test or assumed because of their antibody profile) or those who were infection-naive. Almost all (> 99%) of those who were infection-naive seroconverted after vaccination.

The primary outcome was anti-spike antibody levels assessed according to dose, previous infection, dosing interval, age, ethnicity, and comorbidities, including immunosuppressive disease such as immune system cancers, rheumatologic disease, chronic respiratory diseases, diabetes, obesity, and chronic neurologic disease. 

In the infection-naive group, the mean antibody (anti-S titer) was 75.48 BAU/mL after the first vaccine dose, and this rose to 7,049.76 BAU/mL after the second dose.

The much higher antibody titer with the second dose in infection-naive individuals “is what gives you the most protection, as your antibody titers are at their peak. They then start to gradually wane from this peak,” said Dr. Otter.

In the post-infection group, antibody titers also rose (2,111.08 BAU/mL after first dose and 16,052.39 BAU/mL after second dose), although less so than in the infection-naive group, because of the additional exposure of infection, added Dr. Otter.

Antibody levels also varied according to time elapsed between natural infection and dose 1 of vaccination. With a 3-month interval, antibody levels were 1,970.83 (1,506.01-2,579.1) BAU/mL, compared with 13,759.31 (8,097.78-23,379.09) BAU/mL after a 9-month interval. Antibody levels after one dose in those previously infected are higher than the infection-naive because “previous infection, then vaccination, is likely explained by T-cell expansion upon a boost with a second antigen exposure, and then a maturing memory B-cell response that has been demonstrated up to 6 months,” explained Dr. Otter.

 

Timing of fourth dose

By March of this year, 86.2% of the U.K. population aged over 12 years had received at least two doses, but with rises in disease prevalence and the spread of variants of concern, further work is ongoing to understand the waning of the immune response, level of protection, and why some individuals develop COVID-19 even when double-vaccinated.

This news organization asked Susanna Dunachie, BMChB, professor of infectious diseases, University of Oxford, U.K., what the interval findings might mean for the timing of the fourth dose of vaccine across the U.K. population.

In the United Kingdom, fourth doses are being given to people who are 75 years and older, residents in care homes for older people, and those with weakened immune systems. “To make decisions about fourth doses for healthy people, we need to see how quickly antibody and T-cell responses drop,” said Ms. Dunachie, who is part of the large SIREN study team but was not involved in the analysis led by Dr. Otter. “Current research suggests that the T-cell response may be better maintained than the antibody response, and less affected by variants like Omicron.”

She explained the balance between antibody and T-cell responses to vaccination. “It is likely that antibodies that neutralize the virus are important for preventing any infection at all, and these unfortunately do fall in time, but T-cell responses are better sustained and help keep people out of [the] hospital,” she said.

Ms. Dunachie added that it was necessary to wait and observe what happens next with SARS-CoV-2 evolution, as well as wait for longer follow-up after the third dose in healthy people. “On current evidence, my estimate is we postpone decisions on fourth doses in healthy people to late summer/autumn.”

A version of this article first appeared on Medscape.com.

An overall ninefold increase in COVID-19 antibody levels can be seen with a longer interval between first and second doses of the Pfizer/BioNTech (BNT162b2) vaccine in people without prior infection, according to data from the U.K. government’s SIREN (SARS-CoV-2 Immunity and Reinfection Evaluation) study.

This interval-dependent antibody level varied by age, with those aged 45-54 years showing an 11-fold increase with a longer dosing interval (greater than 10 weeks vs. 2-4 weeks). People younger than age 25 years showed a 13-fold increase with the longer interval, but participant numbers were low in this sub-group.

Overall antibody levels in infection-naive participants were 1,268.72 Binding Antibody Units (BAU)/mL (1,043.25-1,542.91) in those with a 2-4–week interval, compared with 11,479.73 BAU/mL (10,742.78-12,267.24) (P < .0001), in those with at least a 10-week interval between doses.

The work is the latest analysis from SIREN, which measured antibody levels in the blood from nearly 6,000 health care workers from across the United Kingdom. Study lead Ashley Otter, PhD, technical lead for SIREN serology at the UK Health Security Agency (UKHSA), will present the work on Tuesday at the 2022 European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), Lisbon.

In an interview, Dr. Otter noted that, “it is important to remember that antibody levels are only one aspect of the immune response, and in our recent vaccine effectiveness analysis, we found that dosing intervals did not affect protection against infection.”

The study, which appeared in the March issue of the New England Journal of Medicine, also found that after the second dose of vaccine, there was about a 2.5–fold difference in antibody levels between those who had prior infection of 16.052 (14.071-18.312) BAU/mL, compared with 7.050 (6.634-7.491) BAU/mL in infection-naive individuals (P < .0001).

Following the first dose only, antibody levels were up to 10 times higher in participants who were previously infected, compared with infection-naive individuals. This effect lasted up to 8 months and then began to plateau.
 

Natural infection increased antibody levels

Dr. Otter remarked that, “COVID-19 antibody levels are high in those people who were previously naturally infected and vaccinated, highlighting that vaccination provides an additional benefit to these individuals.”

This news organization asked Charlotte Thålin, PhD, an immunologist from the Karolinska Institute, Stockholm, to comment on the study. Dr. Thålin studies a cohort similar to SIREN, called the Swedish COMMUNITY health care worker cohort. “The new data from the SIREN emphasizes the importance of the number of antigenic exposures and the time interval between them, whether it be exposure through vaccination or exposure through infection.” 

“We see similar data in our Swedish COMMUNITY health care worker cohort,” Dr. Thålin continued, “where infection prior to vaccination yields a more than twofold enhancement in antibodies, neutralizing breadth, and T cell responses, and an even larger increase with a longer time interval between infection and vaccination.”

However, she cautioned that they now see a high rate of Omicron vaccine breakthrough infections, and this is also true in people with previous infection and three vaccine doses.

“As we approach a second booster – a fourth vaccine dose – we need to consider that many individuals will have had up to five to six antigen exposures within a short period of time, sometimes within a year,” she pointed out. “This is a whole new scenario, with a lot of different combinations of vaccine and infection-induced immunity. We do not yet know the impact of these frequent immune exposures, and we now need to monitor immune responses following Omicron and booster doses closely.”

SIREN originally aimed to understand how much protection people got after developing a primary infection and why they might become reinfected with COVID-19. Following the rollout of the United Kingdom’s vaccination program, the protective effects of vaccination against COVID-19 were investigated, as well as why some people still become ill after being vaccinated, Dr. Otter explained.

In this latest analysis, Dr. Otter and colleagues assessed anti-spike binding antibodies in serum samples from a total of 5,871 health care workers, with 3,989 after one dose (at least 21 days) and 1,882 after two doses (at least 14 days).

Most participants were women (82.3%), of White ethnicity (87%), and came from across the United Kingdom.

Participants were also categorized into those who had evidence of natural COVID-19 infection (confirmed by a PCR test or assumed because of their antibody profile) or those who were infection-naive. Almost all (> 99%) of those who were infection-naive seroconverted after vaccination.

The primary outcome was anti-spike antibody levels assessed according to dose, previous infection, dosing interval, age, ethnicity, and comorbidities, including immunosuppressive disease such as immune system cancers, rheumatologic disease, chronic respiratory diseases, diabetes, obesity, and chronic neurologic disease. 

In the infection-naive group, the mean antibody (anti-S titer) was 75.48 BAU/mL after the first vaccine dose, and this rose to 7,049.76 BAU/mL after the second dose.

The much higher antibody titer with the second dose in infection-naive individuals “is what gives you the most protection, as your antibody titers are at their peak. They then start to gradually wane from this peak,” said Dr. Otter.

In the post-infection group, antibody titers also rose (2,111.08 BAU/mL after first dose and 16,052.39 BAU/mL after second dose), although less so than in the infection-naive group, because of the additional exposure of infection, added Dr. Otter.

Antibody levels also varied according to time elapsed between natural infection and dose 1 of vaccination. With a 3-month interval, antibody levels were 1,970.83 (1,506.01-2,579.1) BAU/mL, compared with 13,759.31 (8,097.78-23,379.09) BAU/mL after a 9-month interval. Antibody levels after one dose in those previously infected are higher than the infection-naive because “previous infection, then vaccination, is likely explained by T-cell expansion upon a boost with a second antigen exposure, and then a maturing memory B-cell response that has been demonstrated up to 6 months,” explained Dr. Otter.

 

Timing of fourth dose

By March of this year, 86.2% of the U.K. population aged over 12 years had received at least two doses, but with rises in disease prevalence and the spread of variants of concern, further work is ongoing to understand the waning of the immune response, level of protection, and why some individuals develop COVID-19 even when double-vaccinated.

This news organization asked Susanna Dunachie, BMChB, professor of infectious diseases, University of Oxford, U.K., what the interval findings might mean for the timing of the fourth dose of vaccine across the U.K. population.

In the United Kingdom, fourth doses are being given to people who are 75 years and older, residents in care homes for older people, and those with weakened immune systems. “To make decisions about fourth doses for healthy people, we need to see how quickly antibody and T-cell responses drop,” said Ms. Dunachie, who is part of the large SIREN study team but was not involved in the analysis led by Dr. Otter. “Current research suggests that the T-cell response may be better maintained than the antibody response, and less affected by variants like Omicron.”

She explained the balance between antibody and T-cell responses to vaccination. “It is likely that antibodies that neutralize the virus are important for preventing any infection at all, and these unfortunately do fall in time, but T-cell responses are better sustained and help keep people out of [the] hospital,” she said.

Ms. Dunachie added that it was necessary to wait and observe what happens next with SARS-CoV-2 evolution, as well as wait for longer follow-up after the third dose in healthy people. “On current evidence, my estimate is we postpone decisions on fourth doses in healthy people to late summer/autumn.”

A version of this article first appeared on Medscape.com.

An overall ninefold increase in COVID-19 antibody levels can be seen with a longer interval between first and second doses of the Pfizer/BioNTech (BNT162b2) vaccine in people without prior infection, according to data from the U.K. government’s SIREN (SARS-CoV-2 Immunity and Reinfection Evaluation) study.

This interval-dependent antibody level varied by age, with those aged 45-54 years showing an 11-fold increase with a longer dosing interval (greater than 10 weeks vs. 2-4 weeks). People younger than age 25 years showed a 13-fold increase with the longer interval, but participant numbers were low in this sub-group.

Overall antibody levels in infection-naive participants were 1,268.72 Binding Antibody Units (BAU)/mL (1,043.25-1,542.91) in those with a 2-4–week interval, compared with 11,479.73 BAU/mL (10,742.78-12,267.24) (P < .0001), in those with at least a 10-week interval between doses.

The work is the latest analysis from SIREN, which measured antibody levels in the blood from nearly 6,000 health care workers from across the United Kingdom. Study lead Ashley Otter, PhD, technical lead for SIREN serology at the UK Health Security Agency (UKHSA), will present the work on Tuesday at the 2022 European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), Lisbon.

In an interview, Dr. Otter noted that, “it is important to remember that antibody levels are only one aspect of the immune response, and in our recent vaccine effectiveness analysis, we found that dosing intervals did not affect protection against infection.”

The study, which appeared in the March issue of the New England Journal of Medicine, also found that after the second dose of vaccine, there was about a 2.5–fold difference in antibody levels between those who had prior infection of 16.052 (14.071-18.312) BAU/mL, compared with 7.050 (6.634-7.491) BAU/mL in infection-naive individuals (P < .0001).

Following the first dose only, antibody levels were up to 10 times higher in participants who were previously infected, compared with infection-naive individuals. This effect lasted up to 8 months and then began to plateau.
 

Natural infection increased antibody levels

Dr. Otter remarked that, “COVID-19 antibody levels are high in those people who were previously naturally infected and vaccinated, highlighting that vaccination provides an additional benefit to these individuals.”

This news organization asked Charlotte Thålin, PhD, an immunologist from the Karolinska Institute, Stockholm, to comment on the study. Dr. Thålin studies a cohort similar to SIREN, called the Swedish COMMUNITY health care worker cohort. “The new data from the SIREN emphasizes the importance of the number of antigenic exposures and the time interval between them, whether it be exposure through vaccination or exposure through infection.” 

“We see similar data in our Swedish COMMUNITY health care worker cohort,” Dr. Thålin continued, “where infection prior to vaccination yields a more than twofold enhancement in antibodies, neutralizing breadth, and T cell responses, and an even larger increase with a longer time interval between infection and vaccination.”

However, she cautioned that they now see a high rate of Omicron vaccine breakthrough infections, and this is also true in people with previous infection and three vaccine doses.

“As we approach a second booster – a fourth vaccine dose – we need to consider that many individuals will have had up to five to six antigen exposures within a short period of time, sometimes within a year,” she pointed out. “This is a whole new scenario, with a lot of different combinations of vaccine and infection-induced immunity. We do not yet know the impact of these frequent immune exposures, and we now need to monitor immune responses following Omicron and booster doses closely.”

SIREN originally aimed to understand how much protection people got after developing a primary infection and why they might become reinfected with COVID-19. Following the rollout of the United Kingdom’s vaccination program, the protective effects of vaccination against COVID-19 were investigated, as well as why some people still become ill after being vaccinated, Dr. Otter explained.

In this latest analysis, Dr. Otter and colleagues assessed anti-spike binding antibodies in serum samples from a total of 5,871 health care workers, with 3,989 after one dose (at least 21 days) and 1,882 after two doses (at least 14 days).

Most participants were women (82.3%), of White ethnicity (87%), and came from across the United Kingdom.

Participants were also categorized into those who had evidence of natural COVID-19 infection (confirmed by a PCR test or assumed because of their antibody profile) or those who were infection-naive. Almost all (> 99%) of those who were infection-naive seroconverted after vaccination.

The primary outcome was anti-spike antibody levels assessed according to dose, previous infection, dosing interval, age, ethnicity, and comorbidities, including immunosuppressive disease such as immune system cancers, rheumatologic disease, chronic respiratory diseases, diabetes, obesity, and chronic neurologic disease. 

In the infection-naive group, the mean antibody (anti-S titer) was 75.48 BAU/mL after the first vaccine dose, and this rose to 7,049.76 BAU/mL after the second dose.

The much higher antibody titer with the second dose in infection-naive individuals “is what gives you the most protection, as your antibody titers are at their peak. They then start to gradually wane from this peak,” said Dr. Otter.

In the post-infection group, antibody titers also rose (2,111.08 BAU/mL after first dose and 16,052.39 BAU/mL after second dose), although less so than in the infection-naive group, because of the additional exposure of infection, added Dr. Otter.

Antibody levels also varied according to time elapsed between natural infection and dose 1 of vaccination. With a 3-month interval, antibody levels were 1,970.83 (1,506.01-2,579.1) BAU/mL, compared with 13,759.31 (8,097.78-23,379.09) BAU/mL after a 9-month interval. Antibody levels after one dose in those previously infected are higher than the infection-naive because “previous infection, then vaccination, is likely explained by T-cell expansion upon a boost with a second antigen exposure, and then a maturing memory B-cell response that has been demonstrated up to 6 months,” explained Dr. Otter.

 

Timing of fourth dose

By March of this year, 86.2% of the U.K. population aged over 12 years had received at least two doses, but with rises in disease prevalence and the spread of variants of concern, further work is ongoing to understand the waning of the immune response, level of protection, and why some individuals develop COVID-19 even when double-vaccinated.

This news organization asked Susanna Dunachie, BMChB, professor of infectious diseases, University of Oxford, U.K., what the interval findings might mean for the timing of the fourth dose of vaccine across the U.K. population.

In the United Kingdom, fourth doses are being given to people who are 75 years and older, residents in care homes for older people, and those with weakened immune systems. “To make decisions about fourth doses for healthy people, we need to see how quickly antibody and T-cell responses drop,” said Ms. Dunachie, who is part of the large SIREN study team but was not involved in the analysis led by Dr. Otter. “Current research suggests that the T-cell response may be better maintained than the antibody response, and less affected by variants like Omicron.”

She explained the balance between antibody and T-cell responses to vaccination. “It is likely that antibodies that neutralize the virus are important for preventing any infection at all, and these unfortunately do fall in time, but T-cell responses are better sustained and help keep people out of [the] hospital,” she said.

Ms. Dunachie added that it was necessary to wait and observe what happens next with SARS-CoV-2 evolution, as well as wait for longer follow-up after the third dose in healthy people. “On current evidence, my estimate is we postpone decisions on fourth doses in healthy people to late summer/autumn.”

A version of this article first appeared on Medscape.com.

MADRID, Spain – Individuals with substance use disorders are at higher risk of being infected by and dying from COVID-19 – even if they are fully vaccinated – compared with the general population. Such are the findings of a line of research led by Mexican psychiatrist Nora Volkow, MD, director of the U.S. National Institute on Drug Abuse (NIDA).

A pioneer in the use of brain imaging to investigate how substance use affects brain functions and one of Time magazine’s “Top 100 People Who Shape Our World,” she led the Inaugural Conference at the XXXI Congress of the Spanish Society of Clinical Pharmacology “Drugs and Actions During the Pandemic.” Dr. Volkow spoke about the effects that the current health crisis has had on drug use and the social challenges that arose from lockdowns. She also presented and discussed the results of studies being conducted at NIDA that “are aimed at reviewing what we’ve learned and what the consequences of COVID-19 have been with respect to substance abuse disorder.”

As Dr. Volkow pointed out, drugs affect much more than just the brain. “In particular, the heart, the lungs, the immune system – all of these are significantly harmed by substances like tobacco, alcohol, cocaine, and methamphetamine. This is why, since the beginning of the pandemic, we’ve been worried about seeing what consequences SARS-CoV-2 was going to have on users of these substances, especially in light of the great toll this disease takes on the respiratory system and the vascular system.”
 

Pulmonary ‘predisposition’ and race

Dr. Volkow and her team launched several studies to get a more thorough understanding of the link between substance abuse disorders and poor COVID-19 prognoses. One of them was based on analyses from electronic health records in the United States. The purpose was to determine COVID-19 risk and outcomes in patients based on the type of use disorder (for example, alcohol, opioid, cannabis, cocaine).

“The results showed that regardless of the drug type, all users of these substances had both a higher risk of being infected by COVID-19 and a higher death rate in comparison with the rest of the population,” said Dr. Volkow. “This surprised us, because there’s no evidence that drugs themselves make the virus more infectious. However, what the results did clearly indicate to us was that using these substances was associated with behavior that put these individuals at a greater risk for infection,” Dr. Volkow explained.

“In addition,” she continued, “using, for example, tobacco or cannabis causes inflammation in the lungs. It seems that, as a result, they end up being more vulnerable to infection by COVID. And this has consequences, above all, in terms of mortality.”

Another finding was that, among patients with substance use disorders, race had the largest effect on COVID risk. “From the very start, we saw that, compared with White individuals, Black individuals showed a much higher risk of not only getting COVID, but also dying from it,” said Dr. Volkow. “Therefore, on the one hand, our data show that drug users are more vulnerable to COVID-19 and, on the other hand, they reflect that within this group, Black individuals are even more vulnerable.”

In her presentation, Dr. Volkow drew particular attention to the impact that social surroundings have on these patients and the decisive role they played in terms of vulnerability. “It’s a very complex issue, what with the various factors at play: family, social environment. ... A person living in an at-risk situation can more easily get drugs or even prescription medication, which can also be abused.”

The psychiatrist stressed that when it comes to addictive disorders (and related questions such as prevention, treatment, and social reintegration), one of the most crucial factors has to do with the individual’s social support structures. “The studies also brought to light the role that social interaction has as an inhibitory factor with regard to drug use,” said Dr. Volkow. “And indeed, adequate adherence to treatment requires that the necessary support systems be maintained.”

In the context of the pandemic, this social aspect was also key, especially concerning the high death rate among substance use disorder patients with COVID-19. “There are very significant social determinants, such as the stigma associated with these groups – a stigma that makes these individuals more likely to hesitate to seek out treatment for diseases that may be starting to take hold, in this case COVID-19.”

On that note, Dr. Volkow emphasized the importance of treating drug addicts as though they had a chronic disease in need of treatment. “In fact, the prevalence of pathologies such as hypertension, diabetes, cancer, and dementia is much higher in these individuals than in the general population,” she said. “However, this isn’t widely known. The data reflect that not only the prevalence of these diseases, but also the severity of the symptoms, is higher, and this has a lot to do with these individuals’ reticence when it comes to reaching out for medical care. Added to that are the effects of their economic situation and other factors, such as stress (which can trigger a relapse), lack of ready access to medications, and limited access to community support or other sources of social connection.”
 

Opioids and COVID-19

As for drug use during the pandemic, Dr. Volkow provided context by mentioning that in the United States, the experts and authorities have spent two decades fighting the epidemic of opioid-related drug overdoses, which has caused many deaths. “And on top of this epidemic – one that we still haven’t been able to get control of – there’s the situation brought about by COVID-19. So, we had to see the consequences of a pandemic crossing paths with an epidemic.”

The United States’s epidemic of overdose deaths started with the use of opioid painkillers, medications which are overprescribed. Another issue that the United States faces is that many drugs are contaminated with fentanyl. This contamination has caused an increase in deaths.

“In the United States, fentanyl is everywhere,” said Dr. Volkow. “And what’s more concerning: almost a third of this fentanyl comes in pills that are sold as benzodiazepines. With this comes a high risk for overdose. In line with this, we saw overdose deaths among adolescents nearly double in 1 year, an increase which is likely related to these contaminated pills. It’s a risk that’s just below the surface. We’ve got to be vigilant, because this phenomenon is expected to eventually spread to Europe. After all, these pills are very cheap, hence the rapid increase in their use.”

To provide figures on drug use and overdose deaths since the beginning of the pandemic, Dr. Volkow referred to COVID-19 data provided by the National Center for Health Statistics (NCHS) at the U.S. Centers for Disease Control and Prevention. The data indicate that of the 70,630 drug overdose deaths that occurred in 2019, 49,860 involved opioids (whether prescribed or illicit). “And these numbers have continued to rise, so much so that the current situation can be classified as catastrophic – because this increase has been even greater during the pandemic due to the rise in the use of all drugs,” said Dr. Volkow.

Dr. Volkow referred to an NCHS study that looked at the period between September 2020 and September 2021, finding a 15.9% increase in the number of drug overdose deaths. A breakdown of these data shows that the highest percentage corresponds to deaths from “other psychostimulants,” primarily methamphetamines (35.7%). This category is followed by deaths involving synthetic opioids, mostly illicit fentanyl (25.8%), and deaths from cocaine (13.4%).

“These figures indicate that, for the first time in history, the United States had over 100,000 overdose deaths in 1 year,” said Dr. Volkow. “This is something that has never happened. We can only infer that the pandemic had a hand in making the overdose crisis even worse than it already was.”

As Dr. Volkow explained, policies related to handling overdoses and prescribing medications have been changed in the context of COVID-19. Addiction treatment consequently has been provided through a larger number of telehealth services, and measures such as greater access to treatment for comorbid conditions, expanded access to behavioral treatments, and the establishment of mental health hotlines have been undertaken.
 

Children’s cognitive development

Dr. Volkow also spoke about another of NIDA’s current subjects of research: The role that damage or compromise from drugs has on the neural circuits involved in reinforcement systems. “It’s important that we make people aware of the significance of what’s at play there, because the greatest damage that can be inflicted on the brain comes from using any type of drug during adolescence. In these cases, the likelihood of having an addictive disorder as an adult significantly increases.”

Within this framework, her team has also investigated the impact of the pandemic on the cognitive development of infants under 1 year of age. One of these studies was a pilot program in which pregnant women participated. “We found that children born during the pandemic had lower cognitive development: n = 112 versus n = 554 of those born before January 2019.”

“None of the mothers or children in the study had been infected with SARS-CoV-2,” Dr. Volkow explained. “But the results clearly reflect the negative effect of the circumstances brought about by the pandemic, especially the high level of stress, the isolation, and the lack of stimuli. Another study, currently in preprint, is based on imaging. It analyzed the impact on myelination in children not exposed to COVID-19 but born during the pandemic, compared with pre-pandemic infants. The data showed significantly reduced areas of myelin development (P < .05) in those born after 2019. And the researchers didn’t find significant differences in gestation duration or birth weight.”

The longitudinal characteristics of these studies will let us see whether a change in these individuals’ social circumstances over time also brings to light cognitive changes, even the recovery of lost or underdeveloped cognitive processes, Dr. Volkow concluded.

Dr. Volkow has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

MADRID, Spain – Individuals with substance use disorders are at higher risk of being infected by and dying from COVID-19 – even if they are fully vaccinated – compared with the general population. Such are the findings of a line of research led by Mexican psychiatrist Nora Volkow, MD, director of the U.S. National Institute on Drug Abuse (NIDA).

A pioneer in the use of brain imaging to investigate how substance use affects brain functions and one of Time magazine’s “Top 100 People Who Shape Our World,” she led the Inaugural Conference at the XXXI Congress of the Spanish Society of Clinical Pharmacology “Drugs and Actions During the Pandemic.” Dr. Volkow spoke about the effects that the current health crisis has had on drug use and the social challenges that arose from lockdowns. She also presented and discussed the results of studies being conducted at NIDA that “are aimed at reviewing what we’ve learned and what the consequences of COVID-19 have been with respect to substance abuse disorder.”

As Dr. Volkow pointed out, drugs affect much more than just the brain. “In particular, the heart, the lungs, the immune system – all of these are significantly harmed by substances like tobacco, alcohol, cocaine, and methamphetamine. This is why, since the beginning of the pandemic, we’ve been worried about seeing what consequences SARS-CoV-2 was going to have on users of these substances, especially in light of the great toll this disease takes on the respiratory system and the vascular system.”
 

Pulmonary ‘predisposition’ and race

Dr. Volkow and her team launched several studies to get a more thorough understanding of the link between substance abuse disorders and poor COVID-19 prognoses. One of them was based on analyses from electronic health records in the United States. The purpose was to determine COVID-19 risk and outcomes in patients based on the type of use disorder (for example, alcohol, opioid, cannabis, cocaine).

“The results showed that regardless of the drug type, all users of these substances had both a higher risk of being infected by COVID-19 and a higher death rate in comparison with the rest of the population,” said Dr. Volkow. “This surprised us, because there’s no evidence that drugs themselves make the virus more infectious. However, what the results did clearly indicate to us was that using these substances was associated with behavior that put these individuals at a greater risk for infection,” Dr. Volkow explained.

“In addition,” she continued, “using, for example, tobacco or cannabis causes inflammation in the lungs. It seems that, as a result, they end up being more vulnerable to infection by COVID. And this has consequences, above all, in terms of mortality.”

Another finding was that, among patients with substance use disorders, race had the largest effect on COVID risk. “From the very start, we saw that, compared with White individuals, Black individuals showed a much higher risk of not only getting COVID, but also dying from it,” said Dr. Volkow. “Therefore, on the one hand, our data show that drug users are more vulnerable to COVID-19 and, on the other hand, they reflect that within this group, Black individuals are even more vulnerable.”

In her presentation, Dr. Volkow drew particular attention to the impact that social surroundings have on these patients and the decisive role they played in terms of vulnerability. “It’s a very complex issue, what with the various factors at play: family, social environment. ... A person living in an at-risk situation can more easily get drugs or even prescription medication, which can also be abused.”

The psychiatrist stressed that when it comes to addictive disorders (and related questions such as prevention, treatment, and social reintegration), one of the most crucial factors has to do with the individual’s social support structures. “The studies also brought to light the role that social interaction has as an inhibitory factor with regard to drug use,” said Dr. Volkow. “And indeed, adequate adherence to treatment requires that the necessary support systems be maintained.”

In the context of the pandemic, this social aspect was also key, especially concerning the high death rate among substance use disorder patients with COVID-19. “There are very significant social determinants, such as the stigma associated with these groups – a stigma that makes these individuals more likely to hesitate to seek out treatment for diseases that may be starting to take hold, in this case COVID-19.”

On that note, Dr. Volkow emphasized the importance of treating drug addicts as though they had a chronic disease in need of treatment. “In fact, the prevalence of pathologies such as hypertension, diabetes, cancer, and dementia is much higher in these individuals than in the general population,” she said. “However, this isn’t widely known. The data reflect that not only the prevalence of these diseases, but also the severity of the symptoms, is higher, and this has a lot to do with these individuals’ reticence when it comes to reaching out for medical care. Added to that are the effects of their economic situation and other factors, such as stress (which can trigger a relapse), lack of ready access to medications, and limited access to community support or other sources of social connection.”
 

Opioids and COVID-19

As for drug use during the pandemic, Dr. Volkow provided context by mentioning that in the United States, the experts and authorities have spent two decades fighting the epidemic of opioid-related drug overdoses, which has caused many deaths. “And on top of this epidemic – one that we still haven’t been able to get control of – there’s the situation brought about by COVID-19. So, we had to see the consequences of a pandemic crossing paths with an epidemic.”

The United States’s epidemic of overdose deaths started with the use of opioid painkillers, medications which are overprescribed. Another issue that the United States faces is that many drugs are contaminated with fentanyl. This contamination has caused an increase in deaths.

“In the United States, fentanyl is everywhere,” said Dr. Volkow. “And what’s more concerning: almost a third of this fentanyl comes in pills that are sold as benzodiazepines. With this comes a high risk for overdose. In line with this, we saw overdose deaths among adolescents nearly double in 1 year, an increase which is likely related to these contaminated pills. It’s a risk that’s just below the surface. We’ve got to be vigilant, because this phenomenon is expected to eventually spread to Europe. After all, these pills are very cheap, hence the rapid increase in their use.”

To provide figures on drug use and overdose deaths since the beginning of the pandemic, Dr. Volkow referred to COVID-19 data provided by the National Center for Health Statistics (NCHS) at the U.S. Centers for Disease Control and Prevention. The data indicate that of the 70,630 drug overdose deaths that occurred in 2019, 49,860 involved opioids (whether prescribed or illicit). “And these numbers have continued to rise, so much so that the current situation can be classified as catastrophic – because this increase has been even greater during the pandemic due to the rise in the use of all drugs,” said Dr. Volkow.

Dr. Volkow referred to an NCHS study that looked at the period between September 2020 and September 2021, finding a 15.9% increase in the number of drug overdose deaths. A breakdown of these data shows that the highest percentage corresponds to deaths from “other psychostimulants,” primarily methamphetamines (35.7%). This category is followed by deaths involving synthetic opioids, mostly illicit fentanyl (25.8%), and deaths from cocaine (13.4%).

“These figures indicate that, for the first time in history, the United States had over 100,000 overdose deaths in 1 year,” said Dr. Volkow. “This is something that has never happened. We can only infer that the pandemic had a hand in making the overdose crisis even worse than it already was.”

As Dr. Volkow explained, policies related to handling overdoses and prescribing medications have been changed in the context of COVID-19. Addiction treatment consequently has been provided through a larger number of telehealth services, and measures such as greater access to treatment for comorbid conditions, expanded access to behavioral treatments, and the establishment of mental health hotlines have been undertaken.
 

Children’s cognitive development

Dr. Volkow also spoke about another of NIDA’s current subjects of research: The role that damage or compromise from drugs has on the neural circuits involved in reinforcement systems. “It’s important that we make people aware of the significance of what’s at play there, because the greatest damage that can be inflicted on the brain comes from using any type of drug during adolescence. In these cases, the likelihood of having an addictive disorder as an adult significantly increases.”

Within this framework, her team has also investigated the impact of the pandemic on the cognitive development of infants under 1 year of age. One of these studies was a pilot program in which pregnant women participated. “We found that children born during the pandemic had lower cognitive development: n = 112 versus n = 554 of those born before January 2019.”

“None of the mothers or children in the study had been infected with SARS-CoV-2,” Dr. Volkow explained. “But the results clearly reflect the negative effect of the circumstances brought about by the pandemic, especially the high level of stress, the isolation, and the lack of stimuli. Another study, currently in preprint, is based on imaging. It analyzed the impact on myelination in children not exposed to COVID-19 but born during the pandemic, compared with pre-pandemic infants. The data showed significantly reduced areas of myelin development (P < .05) in those born after 2019. And the researchers didn’t find significant differences in gestation duration or birth weight.”

The longitudinal characteristics of these studies will let us see whether a change in these individuals’ social circumstances over time also brings to light cognitive changes, even the recovery of lost or underdeveloped cognitive processes, Dr. Volkow concluded.

Dr. Volkow has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

MADRID, Spain – Individuals with substance use disorders are at higher risk of being infected by and dying from COVID-19 – even if they are fully vaccinated – compared with the general population. Such are the findings of a line of research led by Mexican psychiatrist Nora Volkow, MD, director of the U.S. National Institute on Drug Abuse (NIDA).

A pioneer in the use of brain imaging to investigate how substance use affects brain functions and one of Time magazine’s “Top 100 People Who Shape Our World,” she led the Inaugural Conference at the XXXI Congress of the Spanish Society of Clinical Pharmacology “Drugs and Actions During the Pandemic.” Dr. Volkow spoke about the effects that the current health crisis has had on drug use and the social challenges that arose from lockdowns. She also presented and discussed the results of studies being conducted at NIDA that “are aimed at reviewing what we’ve learned and what the consequences of COVID-19 have been with respect to substance abuse disorder.”

As Dr. Volkow pointed out, drugs affect much more than just the brain. “In particular, the heart, the lungs, the immune system – all of these are significantly harmed by substances like tobacco, alcohol, cocaine, and methamphetamine. This is why, since the beginning of the pandemic, we’ve been worried about seeing what consequences SARS-CoV-2 was going to have on users of these substances, especially in light of the great toll this disease takes on the respiratory system and the vascular system.”
 

Pulmonary ‘predisposition’ and race

Dr. Volkow and her team launched several studies to get a more thorough understanding of the link between substance abuse disorders and poor COVID-19 prognoses. One of them was based on analyses from electronic health records in the United States. The purpose was to determine COVID-19 risk and outcomes in patients based on the type of use disorder (for example, alcohol, opioid, cannabis, cocaine).

“The results showed that regardless of the drug type, all users of these substances had both a higher risk of being infected by COVID-19 and a higher death rate in comparison with the rest of the population,” said Dr. Volkow. “This surprised us, because there’s no evidence that drugs themselves make the virus more infectious. However, what the results did clearly indicate to us was that using these substances was associated with behavior that put these individuals at a greater risk for infection,” Dr. Volkow explained.

“In addition,” she continued, “using, for example, tobacco or cannabis causes inflammation in the lungs. It seems that, as a result, they end up being more vulnerable to infection by COVID. And this has consequences, above all, in terms of mortality.”

Another finding was that, among patients with substance use disorders, race had the largest effect on COVID risk. “From the very start, we saw that, compared with White individuals, Black individuals showed a much higher risk of not only getting COVID, but also dying from it,” said Dr. Volkow. “Therefore, on the one hand, our data show that drug users are more vulnerable to COVID-19 and, on the other hand, they reflect that within this group, Black individuals are even more vulnerable.”

In her presentation, Dr. Volkow drew particular attention to the impact that social surroundings have on these patients and the decisive role they played in terms of vulnerability. “It’s a very complex issue, what with the various factors at play: family, social environment. ... A person living in an at-risk situation can more easily get drugs or even prescription medication, which can also be abused.”

The psychiatrist stressed that when it comes to addictive disorders (and related questions such as prevention, treatment, and social reintegration), one of the most crucial factors has to do with the individual’s social support structures. “The studies also brought to light the role that social interaction has as an inhibitory factor with regard to drug use,” said Dr. Volkow. “And indeed, adequate adherence to treatment requires that the necessary support systems be maintained.”

In the context of the pandemic, this social aspect was also key, especially concerning the high death rate among substance use disorder patients with COVID-19. “There are very significant social determinants, such as the stigma associated with these groups – a stigma that makes these individuals more likely to hesitate to seek out treatment for diseases that may be starting to take hold, in this case COVID-19.”

On that note, Dr. Volkow emphasized the importance of treating drug addicts as though they had a chronic disease in need of treatment. “In fact, the prevalence of pathologies such as hypertension, diabetes, cancer, and dementia is much higher in these individuals than in the general population,” she said. “However, this isn’t widely known. The data reflect that not only the prevalence of these diseases, but also the severity of the symptoms, is higher, and this has a lot to do with these individuals’ reticence when it comes to reaching out for medical care. Added to that are the effects of their economic situation and other factors, such as stress (which can trigger a relapse), lack of ready access to medications, and limited access to community support or other sources of social connection.”
 

Opioids and COVID-19

As for drug use during the pandemic, Dr. Volkow provided context by mentioning that in the United States, the experts and authorities have spent two decades fighting the epidemic of opioid-related drug overdoses, which has caused many deaths. “And on top of this epidemic – one that we still haven’t been able to get control of – there’s the situation brought about by COVID-19. So, we had to see the consequences of a pandemic crossing paths with an epidemic.”

The United States’s epidemic of overdose deaths started with the use of opioid painkillers, medications which are overprescribed. Another issue that the United States faces is that many drugs are contaminated with fentanyl. This contamination has caused an increase in deaths.

“In the United States, fentanyl is everywhere,” said Dr. Volkow. “And what’s more concerning: almost a third of this fentanyl comes in pills that are sold as benzodiazepines. With this comes a high risk for overdose. In line with this, we saw overdose deaths among adolescents nearly double in 1 year, an increase which is likely related to these contaminated pills. It’s a risk that’s just below the surface. We’ve got to be vigilant, because this phenomenon is expected to eventually spread to Europe. After all, these pills are very cheap, hence the rapid increase in their use.”

To provide figures on drug use and overdose deaths since the beginning of the pandemic, Dr. Volkow referred to COVID-19 data provided by the National Center for Health Statistics (NCHS) at the U.S. Centers for Disease Control and Prevention. The data indicate that of the 70,630 drug overdose deaths that occurred in 2019, 49,860 involved opioids (whether prescribed or illicit). “And these numbers have continued to rise, so much so that the current situation can be classified as catastrophic – because this increase has been even greater during the pandemic due to the rise in the use of all drugs,” said Dr. Volkow.

Dr. Volkow referred to an NCHS study that looked at the period between September 2020 and September 2021, finding a 15.9% increase in the number of drug overdose deaths. A breakdown of these data shows that the highest percentage corresponds to deaths from “other psychostimulants,” primarily methamphetamines (35.7%). This category is followed by deaths involving synthetic opioids, mostly illicit fentanyl (25.8%), and deaths from cocaine (13.4%).

“These figures indicate that, for the first time in history, the United States had over 100,000 overdose deaths in 1 year,” said Dr. Volkow. “This is something that has never happened. We can only infer that the pandemic had a hand in making the overdose crisis even worse than it already was.”

As Dr. Volkow explained, policies related to handling overdoses and prescribing medications have been changed in the context of COVID-19. Addiction treatment consequently has been provided through a larger number of telehealth services, and measures such as greater access to treatment for comorbid conditions, expanded access to behavioral treatments, and the establishment of mental health hotlines have been undertaken.
 

Children’s cognitive development

Dr. Volkow also spoke about another of NIDA’s current subjects of research: The role that damage or compromise from drugs has on the neural circuits involved in reinforcement systems. “It’s important that we make people aware of the significance of what’s at play there, because the greatest damage that can be inflicted on the brain comes from using any type of drug during adolescence. In these cases, the likelihood of having an addictive disorder as an adult significantly increases.”

Within this framework, her team has also investigated the impact of the pandemic on the cognitive development of infants under 1 year of age. One of these studies was a pilot program in which pregnant women participated. “We found that children born during the pandemic had lower cognitive development: n = 112 versus n = 554 of those born before January 2019.”

“None of the mothers or children in the study had been infected with SARS-CoV-2,” Dr. Volkow explained. “But the results clearly reflect the negative effect of the circumstances brought about by the pandemic, especially the high level of stress, the isolation, and the lack of stimuli. Another study, currently in preprint, is based on imaging. It analyzed the impact on myelination in children not exposed to COVID-19 but born during the pandemic, compared with pre-pandemic infants. The data showed significantly reduced areas of myelin development (P < .05) in those born after 2019. And the researchers didn’t find significant differences in gestation duration or birth weight.”

The longitudinal characteristics of these studies will let us see whether a change in these individuals’ social circumstances over time also brings to light cognitive changes, even the recovery of lost or underdeveloped cognitive processes, Dr. Volkow concluded.

Dr. Volkow has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

COVID-19 was the third-leading cause of death in the United States in 2021 for the second straight year, with only heart disease and cancer causing more deaths, the Centers for Disease Control and Prevention said April 22.

About 693,000 people died of heart disease in 2021, with 605,000 dying of cancer and 415,000 of COVID, the CDC said, citing provisional data that might be updated later.

Unintentional injuries were the fourth-leading cause of death, increasing to 219,000 in 2021 from 201,000 in 2020. Influenza and pneumonia dropped out of the top 10 leading causes of death and suicide moved into 10th place.

Overall, about 3,458,697 deaths were reported in the United States in 2021. The age-adjusted death rate was 841.6 deaths per 100,000 people, an increase of 0.7% from 2020. The 2021 death rate was the highest since 2003, the CDC said.

The overall number of COVID deaths in 2021 increased around 20% over 2020, when around 384,000 people died from the virus, the CDC said. COVID deaths in 2021 peaked for the weeks ending Jan. 16 and Sept. 11, following holiday periods.

The demographics of COVID mortality changed slightly, the CDC said in a second report.

Blacks accounted for 13.3% of COVID deaths in 2021 and Hispanics 16.5%, down several percentage points from 2020, the CDC said. Asians made up 3.1% of COVID deaths for 2021, a drop from 3.6% in 2020. White people accounted for 65.2% of COVID deaths in 2021, an increase from 59.6% in 2020.

Non-Hispanic American Indian/Alaskan Native and non-Hispanic Black or African American had the highest overall death rates for COVID, the CDC said.

Breaking the data down by age, the number of COVID deaths among people aged 75 years and older dropped to 178,000 in 2021 from around 207,000 in 2020. The numbers went up in other age groups. Among people aged 65-75, about 101,000 died of COVID in 2021, up from around 76,000 in 2020.

“The results of both studies highlight the need for greater effort to implement effective interventions,” the CDC said in a statement. “We must work to ensure equal treatment in all communities in proportion to their need for effective interventions that can prevent excess COVID-19 deaths.”

Since the pandemic began, about 991,000 people in the United States have died from COVID-related causes, the most among all nations in the world.
 

A version of this article first appeared on WebMD.com.

COVID-19 was the third-leading cause of death in the United States in 2021 for the second straight year, with only heart disease and cancer causing more deaths, the Centers for Disease Control and Prevention said April 22.

About 693,000 people died of heart disease in 2021, with 605,000 dying of cancer and 415,000 of COVID, the CDC said, citing provisional data that might be updated later.

Unintentional injuries were the fourth-leading cause of death, increasing to 219,000 in 2021 from 201,000 in 2020. Influenza and pneumonia dropped out of the top 10 leading causes of death and suicide moved into 10th place.

Overall, about 3,458,697 deaths were reported in the United States in 2021. The age-adjusted death rate was 841.6 deaths per 100,000 people, an increase of 0.7% from 2020. The 2021 death rate was the highest since 2003, the CDC said.

The overall number of COVID deaths in 2021 increased around 20% over 2020, when around 384,000 people died from the virus, the CDC said. COVID deaths in 2021 peaked for the weeks ending Jan. 16 and Sept. 11, following holiday periods.

The demographics of COVID mortality changed slightly, the CDC said in a second report.

Blacks accounted for 13.3% of COVID deaths in 2021 and Hispanics 16.5%, down several percentage points from 2020, the CDC said. Asians made up 3.1% of COVID deaths for 2021, a drop from 3.6% in 2020. White people accounted for 65.2% of COVID deaths in 2021, an increase from 59.6% in 2020.

Non-Hispanic American Indian/Alaskan Native and non-Hispanic Black or African American had the highest overall death rates for COVID, the CDC said.

Breaking the data down by age, the number of COVID deaths among people aged 75 years and older dropped to 178,000 in 2021 from around 207,000 in 2020. The numbers went up in other age groups. Among people aged 65-75, about 101,000 died of COVID in 2021, up from around 76,000 in 2020.

“The results of both studies highlight the need for greater effort to implement effective interventions,” the CDC said in a statement. “We must work to ensure equal treatment in all communities in proportion to their need for effective interventions that can prevent excess COVID-19 deaths.”

Since the pandemic began, about 991,000 people in the United States have died from COVID-related causes, the most among all nations in the world.
 

A version of this article first appeared on WebMD.com.

COVID-19 was the third-leading cause of death in the United States in 2021 for the second straight year, with only heart disease and cancer causing more deaths, the Centers for Disease Control and Prevention said April 22.

About 693,000 people died of heart disease in 2021, with 605,000 dying of cancer and 415,000 of COVID, the CDC said, citing provisional data that might be updated later.

Unintentional injuries were the fourth-leading cause of death, increasing to 219,000 in 2021 from 201,000 in 2020. Influenza and pneumonia dropped out of the top 10 leading causes of death and suicide moved into 10th place.

Overall, about 3,458,697 deaths were reported in the United States in 2021. The age-adjusted death rate was 841.6 deaths per 100,000 people, an increase of 0.7% from 2020. The 2021 death rate was the highest since 2003, the CDC said.

The overall number of COVID deaths in 2021 increased around 20% over 2020, when around 384,000 people died from the virus, the CDC said. COVID deaths in 2021 peaked for the weeks ending Jan. 16 and Sept. 11, following holiday periods.

The demographics of COVID mortality changed slightly, the CDC said in a second report.

Blacks accounted for 13.3% of COVID deaths in 2021 and Hispanics 16.5%, down several percentage points from 2020, the CDC said. Asians made up 3.1% of COVID deaths for 2021, a drop from 3.6% in 2020. White people accounted for 65.2% of COVID deaths in 2021, an increase from 59.6% in 2020.

Non-Hispanic American Indian/Alaskan Native and non-Hispanic Black or African American had the highest overall death rates for COVID, the CDC said.

Breaking the data down by age, the number of COVID deaths among people aged 75 years and older dropped to 178,000 in 2021 from around 207,000 in 2020. The numbers went up in other age groups. Among people aged 65-75, about 101,000 died of COVID in 2021, up from around 76,000 in 2020.

“The results of both studies highlight the need for greater effort to implement effective interventions,” the CDC said in a statement. “We must work to ensure equal treatment in all communities in proportion to their need for effective interventions that can prevent excess COVID-19 deaths.”

Since the pandemic began, about 991,000 people in the United States have died from COVID-related causes, the most among all nations in the world.
 

A version of this article first appeared on WebMD.com.

One of the largest studies to date on myocarditis after COVID-19 vaccination confirms an increased risk with both the Pfizer and Moderna vaccines in young men and shows that the risk is higher with the Moderna than with the Pfizer vaccine.

The study also suggests for the first time that in young men 16 to 24 years of age, the risk for myocarditis after vaccination with either the Pfizer or Moderna vaccine is higher than the risk for myocarditis after COVID-19 infection.

The population-based study involved data on 23.1 million residents across four Scandinavian countries – Denmark, Finland, Norway, and Sweden – 74% of whom had received two vaccine doses and 7% of whom had received one dose.

By linking data from high-quality nationwide health registers on COVID-19 vaccination, infection rates, and myocarditis diagnoses, the researchers were able to evaluate the risk for myocarditis by vaccine product, vaccination dose number, sex, and age.

The study was published online in JAMA Cardiology.

The results confirm that the risk for myocarditis after COVID-19 mRNA vaccines is highest in young men 16 to 24 years of age after the second dose.

For men in this age group who received two doses of the same vaccine, data were compatible, with between four and seven excess myocarditis events in 28 days per 100,000 individuals after the second dose of the Pfizer vaccine, and between nine and 28 per 100,000 individuals after the second dose of the Moderna vaccine.

“This is one of the largest studies on this topic to date. The first population studies were in Israel, with 5 million individuals, and looked at just the Pfizer vaccine. We have data on 23 million people from Scandinavia that include both the Pfizer and Moderna vaccines,” senior author Rickard Ljung, MD, Swedish Medical Products Agency, told this news organization.

“We show a clearly higher risk of myocarditis after the Moderna vaccine than after the Pfizer vaccine. This has been suggested before, but our data confirm definitively that the Moderna vaccine has a higher risk of myocarditis than the Pfizer vaccine,” he added.

“In the group at highest risk of myocarditis after COVID vaccination – young men aged 16 to 24 – the Pfizer vaccine shows a five times higher risk of myocarditis versus the unvaccinated cohort, while the Moderna vaccine shows a 15 times higher risk,” Dr. Ljung noted.

After seeing these data, the Swedish regulatory authority is no longer recommending use of the Moderna vaccine for people younger than 30 years, Dr. Ljung said. Similar recommendations have been made in Norway and Finland.

The researchers report that their finding of a higher risk for myocarditis after the Moderna vaccine than after the Pfizer vaccine in young men is in line with data from the Canada, France, the United Kingdom, and the United States. But they point out that, compared with previous studies, the current study had the advantage of data analyzed according to a common protocol from four different countries and that showed similar directions of associations, despite considerable differences in previous COVID-19 infection levels and lockdown policies.

Risk higher with vaccination than infection?

For what is believed to be the first time, the Scandinavian data also suggest a higher risk for myocarditis after COVID-19 vaccination with both the Pfizer and Moderna vaccines than after COVID-19 infection in young men 16 to 24 years.

Although previous studies have shown that males in this age group have the highest risk for myocarditis after vaccination, it has always been suggested that the risk after vaccination is lower than the risk after infection. The Scandinavian data suggest otherwise for this age group.

Dr. Ljung explained that the myocarditis risk after COVID infection is very hard to study.

“It is highly dependent on the testing strategy,” he said. “For example, in the first half of 2020, the only people being tested were those admitted to hospital, so studies would have included the sickest patients and would therefore likely have found a higher rate of myocarditis. But this current Scandinavian dataset only included individuals with a positive COVID test after August 2020, reflecting a broader range of people.”

The researchers found an excess rate of myocarditis of 3.26 per 100,000 individuals within 28 days of a positive COVID-19 test among all males, and 1.37 per 100,000 individuals among males 16 to 24 years of age.

“We show that the risk of myocarditis after COVID infection is lower in younger people and higher in older people, but the opposite is true after COVID vaccination, where the risk of myocarditis is higher in younger people and lower in older people,” Dr. Ljung said.

The study was not able to look at severity of myocarditis but did record length of hospital stay, which was similar in patients who developed myocarditis after vaccination and those in the unvaccinated cohort (4 to 5 days). Deaths were rare, with no deaths in people younger than 40 years.

“I think we can say that in people aged over 40, the risk of myocarditis is greater with infection than with vaccination, but in those under 40, it is not so clear. And our data suggest that for young men aged 16 to 24 years, the risk of myocarditis after COVID vaccination with either the Pfizer or Moderna vaccine is higher than after COVID infection,” Dr. Ljung commented.

Although the Swedish regulatory agency has already stopped recommending use of Moderna vaccine in those younger than 30 years on the basis of these data, Dr. Ljung was reluctant to make any recommendations regarding the use of the Pfizer vaccine in young males, saying it was up to individual public-health agencies to makes these decisions. 

But he pointed out that the current study only looked at myocarditis, and COVID infection can result in many other complications that can lead to hospitalization and death, which needs to be taken into account when assessing the risk and benefit of vaccination.

Dr. Ljung noted that the current data only applied to the first two doses of the vaccines; data after booster injections have not been included, although the researchers are looking at that now.

What to advise patients?

In an accompanying Editor’s Note, Ann Marie Navar, MD, University of Texas Southwestern Medical Center, Dallas, who is editor of JAMA Cardiology, and Robert Bonow, MD, Northwestern University Feinberg School of Medicine, Chicago, who is deputy editor of JAMA Cardiology, try to explain how these data can inform the way health care professionals communicate with their patients about vaccination.

They point out the “good news,” that older adults who are at highest risk for COVID-19 complications appear to be at extremely low risk for vaccine-associated myocarditis.

They note that for both men and women older than 40 years, the excess number of cases of myocarditis after vaccination was fewer than two in 100,000 vaccinees across all vaccines studied, and the death toll from COVID-19 in the United States as of March was more than 200 per 100,000 population.

“Given the high rates of morbidity and mortality from COVID-19 infection in older adults and the efficacy of the vaccine in preventing severe infection and death, the benefits of immunization in those older than 40 years clearly outweigh the risks,” the editors say.

But given these data in young men, they suggest that health care professionals consider recommending the Pfizer vaccine over the Moderna vaccine for certain populations, including young men and other individuals for whom concerns about myocarditis present a barrier to immunization.

The editors also point out that although the risk for myocarditis after COVID-19 immunization is real, this low risk must be considered in the context of the overall benefit of the vaccine.

“At the individual level, immunization prevents not only COVID-19-related myocarditis but also severe disease, hospitalization, long-term complications after COVID-19 infection, and death. At the population level, immunization helps to decrease community spread, decrease the chances of new variants emerging, protect people who are immunocompromised, and ensure our health care system can continue to provide for our communities,” they conclude.

Dr. Ljung reports grants from Sanofi Aventis paid to his institution outside the submitted work and personal fees from Pfizer outside the submitted work. Dr. Navar reports personal fees from Pfizer and AstraZeneca, outside the scope of this work.

A version of this article first appeared on Medscape.com.

One of the largest studies to date on myocarditis after COVID-19 vaccination confirms an increased risk with both the Pfizer and Moderna vaccines in young men and shows that the risk is higher with the Moderna than with the Pfizer vaccine.

The study also suggests for the first time that in young men 16 to 24 years of age, the risk for myocarditis after vaccination with either the Pfizer or Moderna vaccine is higher than the risk for myocarditis after COVID-19 infection.

The population-based study involved data on 23.1 million residents across four Scandinavian countries – Denmark, Finland, Norway, and Sweden – 74% of whom had received two vaccine doses and 7% of whom had received one dose.

By linking data from high-quality nationwide health registers on COVID-19 vaccination, infection rates, and myocarditis diagnoses, the researchers were able to evaluate the risk for myocarditis by vaccine product, vaccination dose number, sex, and age.

The study was published online in JAMA Cardiology.

The results confirm that the risk for myocarditis after COVID-19 mRNA vaccines is highest in young men 16 to 24 years of age after the second dose.

For men in this age group who received two doses of the same vaccine, data were compatible, with between four and seven excess myocarditis events in 28 days per 100,000 individuals after the second dose of the Pfizer vaccine, and between nine and 28 per 100,000 individuals after the second dose of the Moderna vaccine.

“This is one of the largest studies on this topic to date. The first population studies were in Israel, with 5 million individuals, and looked at just the Pfizer vaccine. We have data on 23 million people from Scandinavia that include both the Pfizer and Moderna vaccines,” senior author Rickard Ljung, MD, Swedish Medical Products Agency, told this news organization.

“We show a clearly higher risk of myocarditis after the Moderna vaccine than after the Pfizer vaccine. This has been suggested before, but our data confirm definitively that the Moderna vaccine has a higher risk of myocarditis than the Pfizer vaccine,” he added.

“In the group at highest risk of myocarditis after COVID vaccination – young men aged 16 to 24 – the Pfizer vaccine shows a five times higher risk of myocarditis versus the unvaccinated cohort, while the Moderna vaccine shows a 15 times higher risk,” Dr. Ljung noted.

After seeing these data, the Swedish regulatory authority is no longer recommending use of the Moderna vaccine for people younger than 30 years, Dr. Ljung said. Similar recommendations have been made in Norway and Finland.

The researchers report that their finding of a higher risk for myocarditis after the Moderna vaccine than after the Pfizer vaccine in young men is in line with data from the Canada, France, the United Kingdom, and the United States. But they point out that, compared with previous studies, the current study had the advantage of data analyzed according to a common protocol from four different countries and that showed similar directions of associations, despite considerable differences in previous COVID-19 infection levels and lockdown policies.

Risk higher with vaccination than infection?

For what is believed to be the first time, the Scandinavian data also suggest a higher risk for myocarditis after COVID-19 vaccination with both the Pfizer and Moderna vaccines than after COVID-19 infection in young men 16 to 24 years.

Although previous studies have shown that males in this age group have the highest risk for myocarditis after vaccination, it has always been suggested that the risk after vaccination is lower than the risk after infection. The Scandinavian data suggest otherwise for this age group.

Dr. Ljung explained that the myocarditis risk after COVID infection is very hard to study.

“It is highly dependent on the testing strategy,” he said. “For example, in the first half of 2020, the only people being tested were those admitted to hospital, so studies would have included the sickest patients and would therefore likely have found a higher rate of myocarditis. But this current Scandinavian dataset only included individuals with a positive COVID test after August 2020, reflecting a broader range of people.”

The researchers found an excess rate of myocarditis of 3.26 per 100,000 individuals within 28 days of a positive COVID-19 test among all males, and 1.37 per 100,000 individuals among males 16 to 24 years of age.

“We show that the risk of myocarditis after COVID infection is lower in younger people and higher in older people, but the opposite is true after COVID vaccination, where the risk of myocarditis is higher in younger people and lower in older people,” Dr. Ljung said.

The study was not able to look at severity of myocarditis but did record length of hospital stay, which was similar in patients who developed myocarditis after vaccination and those in the unvaccinated cohort (4 to 5 days). Deaths were rare, with no deaths in people younger than 40 years.

“I think we can say that in people aged over 40, the risk of myocarditis is greater with infection than with vaccination, but in those under 40, it is not so clear. And our data suggest that for young men aged 16 to 24 years, the risk of myocarditis after COVID vaccination with either the Pfizer or Moderna vaccine is higher than after COVID infection,” Dr. Ljung commented.

Although the Swedish regulatory agency has already stopped recommending use of Moderna vaccine in those younger than 30 years on the basis of these data, Dr. Ljung was reluctant to make any recommendations regarding the use of the Pfizer vaccine in young males, saying it was up to individual public-health agencies to makes these decisions. 

But he pointed out that the current study only looked at myocarditis, and COVID infection can result in many other complications that can lead to hospitalization and death, which needs to be taken into account when assessing the risk and benefit of vaccination.

Dr. Ljung noted that the current data only applied to the first two doses of the vaccines; data after booster injections have not been included, although the researchers are looking at that now.

What to advise patients?

In an accompanying Editor’s Note, Ann Marie Navar, MD, University of Texas Southwestern Medical Center, Dallas, who is editor of JAMA Cardiology, and Robert Bonow, MD, Northwestern University Feinberg School of Medicine, Chicago, who is deputy editor of JAMA Cardiology, try to explain how these data can inform the way health care professionals communicate with their patients about vaccination.

They point out the “good news,” that older adults who are at highest risk for COVID-19 complications appear to be at extremely low risk for vaccine-associated myocarditis.

They note that for both men and women older than 40 years, the excess number of cases of myocarditis after vaccination was fewer than two in 100,000 vaccinees across all vaccines studied, and the death toll from COVID-19 in the United States as of March was more than 200 per 100,000 population.

“Given the high rates of morbidity and mortality from COVID-19 infection in older adults and the efficacy of the vaccine in preventing severe infection and death, the benefits of immunization in those older than 40 years clearly outweigh the risks,” the editors say.

But given these data in young men, they suggest that health care professionals consider recommending the Pfizer vaccine over the Moderna vaccine for certain populations, including young men and other individuals for whom concerns about myocarditis present a barrier to immunization.

The editors also point out that although the risk for myocarditis after COVID-19 immunization is real, this low risk must be considered in the context of the overall benefit of the vaccine.

“At the individual level, immunization prevents not only COVID-19-related myocarditis but also severe disease, hospitalization, long-term complications after COVID-19 infection, and death. At the population level, immunization helps to decrease community spread, decrease the chances of new variants emerging, protect people who are immunocompromised, and ensure our health care system can continue to provide for our communities,” they conclude.

Dr. Ljung reports grants from Sanofi Aventis paid to his institution outside the submitted work and personal fees from Pfizer outside the submitted work. Dr. Navar reports personal fees from Pfizer and AstraZeneca, outside the scope of this work.

A version of this article first appeared on Medscape.com.

One of the largest studies to date on myocarditis after COVID-19 vaccination confirms an increased risk with both the Pfizer and Moderna vaccines in young men and shows that the risk is higher with the Moderna than with the Pfizer vaccine.

The study also suggests for the first time that in young men 16 to 24 years of age, the risk for myocarditis after vaccination with either the Pfizer or Moderna vaccine is higher than the risk for myocarditis after COVID-19 infection.

The population-based study involved data on 23.1 million residents across four Scandinavian countries – Denmark, Finland, Norway, and Sweden – 74% of whom had received two vaccine doses and 7% of whom had received one dose.

By linking data from high-quality nationwide health registers on COVID-19 vaccination, infection rates, and myocarditis diagnoses, the researchers were able to evaluate the risk for myocarditis by vaccine product, vaccination dose number, sex, and age.

The study was published online in JAMA Cardiology.

The results confirm that the risk for myocarditis after COVID-19 mRNA vaccines is highest in young men 16 to 24 years of age after the second dose.

For men in this age group who received two doses of the same vaccine, data were compatible, with between four and seven excess myocarditis events in 28 days per 100,000 individuals after the second dose of the Pfizer vaccine, and between nine and 28 per 100,000 individuals after the second dose of the Moderna vaccine.

“This is one of the largest studies on this topic to date. The first population studies were in Israel, with 5 million individuals, and looked at just the Pfizer vaccine. We have data on 23 million people from Scandinavia that include both the Pfizer and Moderna vaccines,” senior author Rickard Ljung, MD, Swedish Medical Products Agency, told this news organization.

“We show a clearly higher risk of myocarditis after the Moderna vaccine than after the Pfizer vaccine. This has been suggested before, but our data confirm definitively that the Moderna vaccine has a higher risk of myocarditis than the Pfizer vaccine,” he added.

“In the group at highest risk of myocarditis after COVID vaccination – young men aged 16 to 24 – the Pfizer vaccine shows a five times higher risk of myocarditis versus the unvaccinated cohort, while the Moderna vaccine shows a 15 times higher risk,” Dr. Ljung noted.

After seeing these data, the Swedish regulatory authority is no longer recommending use of the Moderna vaccine for people younger than 30 years, Dr. Ljung said. Similar recommendations have been made in Norway and Finland.

The researchers report that their finding of a higher risk for myocarditis after the Moderna vaccine than after the Pfizer vaccine in young men is in line with data from the Canada, France, the United Kingdom, and the United States. But they point out that, compared with previous studies, the current study had the advantage of data analyzed according to a common protocol from four different countries and that showed similar directions of associations, despite considerable differences in previous COVID-19 infection levels and lockdown policies.

Risk higher with vaccination than infection?

For what is believed to be the first time, the Scandinavian data also suggest a higher risk for myocarditis after COVID-19 vaccination with both the Pfizer and Moderna vaccines than after COVID-19 infection in young men 16 to 24 years.

Although previous studies have shown that males in this age group have the highest risk for myocarditis after vaccination, it has always been suggested that the risk after vaccination is lower than the risk after infection. The Scandinavian data suggest otherwise for this age group.

Dr. Ljung explained that the myocarditis risk after COVID infection is very hard to study.

“It is highly dependent on the testing strategy,” he said. “For example, in the first half of 2020, the only people being tested were those admitted to hospital, so studies would have included the sickest patients and would therefore likely have found a higher rate of myocarditis. But this current Scandinavian dataset only included individuals with a positive COVID test after August 2020, reflecting a broader range of people.”

The researchers found an excess rate of myocarditis of 3.26 per 100,000 individuals within 28 days of a positive COVID-19 test among all males, and 1.37 per 100,000 individuals among males 16 to 24 years of age.

“We show that the risk of myocarditis after COVID infection is lower in younger people and higher in older people, but the opposite is true after COVID vaccination, where the risk of myocarditis is higher in younger people and lower in older people,” Dr. Ljung said.

The study was not able to look at severity of myocarditis but did record length of hospital stay, which was similar in patients who developed myocarditis after vaccination and those in the unvaccinated cohort (4 to 5 days). Deaths were rare, with no deaths in people younger than 40 years.

“I think we can say that in people aged over 40, the risk of myocarditis is greater with infection than with vaccination, but in those under 40, it is not so clear. And our data suggest that for young men aged 16 to 24 years, the risk of myocarditis after COVID vaccination with either the Pfizer or Moderna vaccine is higher than after COVID infection,” Dr. Ljung commented.

Although the Swedish regulatory agency has already stopped recommending use of Moderna vaccine in those younger than 30 years on the basis of these data, Dr. Ljung was reluctant to make any recommendations regarding the use of the Pfizer vaccine in young males, saying it was up to individual public-health agencies to makes these decisions. 

But he pointed out that the current study only looked at myocarditis, and COVID infection can result in many other complications that can lead to hospitalization and death, which needs to be taken into account when assessing the risk and benefit of vaccination.

Dr. Ljung noted that the current data only applied to the first two doses of the vaccines; data after booster injections have not been included, although the researchers are looking at that now.

What to advise patients?

In an accompanying Editor’s Note, Ann Marie Navar, MD, University of Texas Southwestern Medical Center, Dallas, who is editor of JAMA Cardiology, and Robert Bonow, MD, Northwestern University Feinberg School of Medicine, Chicago, who is deputy editor of JAMA Cardiology, try to explain how these data can inform the way health care professionals communicate with their patients about vaccination.

They point out the “good news,” that older adults who are at highest risk for COVID-19 complications appear to be at extremely low risk for vaccine-associated myocarditis.

They note that for both men and women older than 40 years, the excess number of cases of myocarditis after vaccination was fewer than two in 100,000 vaccinees across all vaccines studied, and the death toll from COVID-19 in the United States as of March was more than 200 per 100,000 population.

“Given the high rates of morbidity and mortality from COVID-19 infection in older adults and the efficacy of the vaccine in preventing severe infection and death, the benefits of immunization in those older than 40 years clearly outweigh the risks,” the editors say.

But given these data in young men, they suggest that health care professionals consider recommending the Pfizer vaccine over the Moderna vaccine for certain populations, including young men and other individuals for whom concerns about myocarditis present a barrier to immunization.

The editors also point out that although the risk for myocarditis after COVID-19 immunization is real, this low risk must be considered in the context of the overall benefit of the vaccine.

“At the individual level, immunization prevents not only COVID-19-related myocarditis but also severe disease, hospitalization, long-term complications after COVID-19 infection, and death. At the population level, immunization helps to decrease community spread, decrease the chances of new variants emerging, protect people who are immunocompromised, and ensure our health care system can continue to provide for our communities,” they conclude.

Dr. Ljung reports grants from Sanofi Aventis paid to his institution outside the submitted work and personal fees from Pfizer outside the submitted work. Dr. Navar reports personal fees from Pfizer and AstraZeneca, outside the scope of this work.

A version of this article first appeared on Medscape.com.

The Centers for Disease Control and Prevention is considering what to tell the public about second booster shots with mRNA vaccinations for COVID-19.

The U.S. Food and Drug Administration in March authorized a second booster dose of either the Pfizer-BioNTech or the Moderna COVID-19 vaccines for people aged 50 and older and certain immunocompromised adults, even though many top infectious disease experts questioned the need before the agency’s decision.

In a meeting April 20, the CDC asked its Advisory Committee on Immunization Practices to discuss second booster shots, but did not ask the group of experts to vote on formal recommendations.

Instead, the experts talked about the potential timing of additional COVID-19 vaccines for those who already have had three shots, and challenges for vaccination efforts that likely will arise as the pandemic persists.

ACIP member Beth Bell, MD, MPH, of the University of Washington, Seattle, said she’s concerned about the potential for “booster fatigue.”

“A vaccination program that’s going to require boosting large proportions of the population every 4-6 months is really not sustainable and probably not something that most people want to participate in,” she said.

The benefit of additional COVID-19 shots for now appears to be smaller than what people get from the initial doses, Dr. Bell said.

Earlier in the meeting, CDC staff presented estimates about how well the COVID-19 vaccines work to prevent one case of hospitalization from the disease over 4 months among people aged 50 and older.

The major gain in preventing hospitalizations occurs with the first vaccination series and then wanes, the CDC said.

It appears that one hospitalization is prevented for every 135 people who get the first round of COVID-19 vaccinations. But it takes 674 people getting a first booster dose to prevent one hospitalization. A second booster prevents one hospitalization for every 1,205 people vaccinated.

Dr. Bell said she’s concerned about considering additional doses for “smaller and smaller return and creating an impression that we don’t have a very effective vaccination program,” even though the CDC’s data show a clear benefit.
 

Reasons to get a second booster

Elisha Hall, PhD, RD, of the CDC presented slides with some factors to help determine the urgency for a person to get a second booster:

• Having certain underlying medical conditions that increase the risk of severe COVID-19 illness.
• Being moderately or severely immunocompromised.
• Living with someone who is immunocompromised, at increased risk for severe disease, or who cannot be vaccinated because of age or contraindication.
• Being at increased risk of exposure to SARS-CoV-2, the virus that causes COVID-19, such as through occupational, institutional, or other activities (e.g., travel or large gatherings).
• Living or working in an area where there is a medium or high level of COVID-19 in the community.

In contrast, people might want to wait if they had been infected with SARS-CoV-2 within the past 3 months, Dr. Hall said in her presentation. Another reason for delay might be a concern that a booster dose may be more important later in the year.

The experts also addressed public confusion over boosters. For the Pfizer and Moderna mRNA vaccines, a second booster is a fourth dose, but for those who received the one-shot J&J vaccine, the second booster is a third dose.

Going forward, it may be easier to refer to subsequent doses as “annual boosters,” the CDC’s Sara Oliver, MD, MSPH, told the panel. It will be important to keep language about subsequent vaccinations clear and easy for the public to follow, she said.

Dr. Oliver also said there’s already been a drop-off in the acceptance of second rounds of COVID-19 vaccinations. CDC data show that 77% of people in the United States have had at least one dose of a COVID-19 vaccine, but only 66% of the population is fully vaccinated, and only 45% have had a first booster dose.

In her presentation, Dr. Oliver said the top priority in COVID-19 vaccination efforts remains initial vaccinations for people who haven’t gotten them.
 

Kids younger than 5

During the public comment session of the CDC meeting, several people called on the FDA to move quickly to expand authorization of COVID-19 vaccines to children aged 5 years and younger.

“We know that many parents and caregivers and health care providers are anxious to have COVID vaccines available” for young children, said Doran Fink, MD, PhD, a deputy director of the FDA’s vaccines division.

He said the agency is working to be ready to authorize the shots for young children while it awaits research results from the manufacturers.

A version of this article first appeared on WebMD.com.

The Centers for Disease Control and Prevention is considering what to tell the public about second booster shots with mRNA vaccinations for COVID-19.

The U.S. Food and Drug Administration in March authorized a second booster dose of either the Pfizer-BioNTech or the Moderna COVID-19 vaccines for people aged 50 and older and certain immunocompromised adults, even though many top infectious disease experts questioned the need before the agency’s decision.

In a meeting April 20, the CDC asked its Advisory Committee on Immunization Practices to discuss second booster shots, but did not ask the group of experts to vote on formal recommendations.

Instead, the experts talked about the potential timing of additional COVID-19 vaccines for those who already have had three shots, and challenges for vaccination efforts that likely will arise as the pandemic persists.

ACIP member Beth Bell, MD, MPH, of the University of Washington, Seattle, said she’s concerned about the potential for “booster fatigue.”

“A vaccination program that’s going to require boosting large proportions of the population every 4-6 months is really not sustainable and probably not something that most people want to participate in,” she said.

The benefit of additional COVID-19 shots for now appears to be smaller than what people get from the initial doses, Dr. Bell said.

Earlier in the meeting, CDC staff presented estimates about how well the COVID-19 vaccines work to prevent one case of hospitalization from the disease over 4 months among people aged 50 and older.

The major gain in preventing hospitalizations occurs with the first vaccination series and then wanes, the CDC said.

It appears that one hospitalization is prevented for every 135 people who get the first round of COVID-19 vaccinations. But it takes 674 people getting a first booster dose to prevent one hospitalization. A second booster prevents one hospitalization for every 1,205 people vaccinated.

Dr. Bell said she’s concerned about considering additional doses for “smaller and smaller return and creating an impression that we don’t have a very effective vaccination program,” even though the CDC’s data show a clear benefit.
 

Reasons to get a second booster

Elisha Hall, PhD, RD, of the CDC presented slides with some factors to help determine the urgency for a person to get a second booster:

• Having certain underlying medical conditions that increase the risk of severe COVID-19 illness.
• Being moderately or severely immunocompromised.
• Living with someone who is immunocompromised, at increased risk for severe disease, or who cannot be vaccinated because of age or contraindication.
• Being at increased risk of exposure to SARS-CoV-2, the virus that causes COVID-19, such as through occupational, institutional, or other activities (e.g., travel or large gatherings).
• Living or working in an area where there is a medium or high level of COVID-19 in the community.

In contrast, people might want to wait if they had been infected with SARS-CoV-2 within the past 3 months, Dr. Hall said in her presentation. Another reason for delay might be a concern that a booster dose may be more important later in the year.

The experts also addressed public confusion over boosters. For the Pfizer and Moderna mRNA vaccines, a second booster is a fourth dose, but for those who received the one-shot J&J vaccine, the second booster is a third dose.

Going forward, it may be easier to refer to subsequent doses as “annual boosters,” the CDC’s Sara Oliver, MD, MSPH, told the panel. It will be important to keep language about subsequent vaccinations clear and easy for the public to follow, she said.

Dr. Oliver also said there’s already been a drop-off in the acceptance of second rounds of COVID-19 vaccinations. CDC data show that 77% of people in the United States have had at least one dose of a COVID-19 vaccine, but only 66% of the population is fully vaccinated, and only 45% have had a first booster dose.

In her presentation, Dr. Oliver said the top priority in COVID-19 vaccination efforts remains initial vaccinations for people who haven’t gotten them.
 

Kids younger than 5

During the public comment session of the CDC meeting, several people called on the FDA to move quickly to expand authorization of COVID-19 vaccines to children aged 5 years and younger.

“We know that many parents and caregivers and health care providers are anxious to have COVID vaccines available” for young children, said Doran Fink, MD, PhD, a deputy director of the FDA’s vaccines division.

He said the agency is working to be ready to authorize the shots for young children while it awaits research results from the manufacturers.

A version of this article first appeared on WebMD.com.

The Centers for Disease Control and Prevention is considering what to tell the public about second booster shots with mRNA vaccinations for COVID-19.

The U.S. Food and Drug Administration in March authorized a second booster dose of either the Pfizer-BioNTech or the Moderna COVID-19 vaccines for people aged 50 and older and certain immunocompromised adults, even though many top infectious disease experts questioned the need before the agency’s decision.

In a meeting April 20, the CDC asked its Advisory Committee on Immunization Practices to discuss second booster shots, but did not ask the group of experts to vote on formal recommendations.

Instead, the experts talked about the potential timing of additional COVID-19 vaccines for those who already have had three shots, and challenges for vaccination efforts that likely will arise as the pandemic persists.

ACIP member Beth Bell, MD, MPH, of the University of Washington, Seattle, said she’s concerned about the potential for “booster fatigue.”

“A vaccination program that’s going to require boosting large proportions of the population every 4-6 months is really not sustainable and probably not something that most people want to participate in,” she said.

The benefit of additional COVID-19 shots for now appears to be smaller than what people get from the initial doses, Dr. Bell said.

Earlier in the meeting, CDC staff presented estimates about how well the COVID-19 vaccines work to prevent one case of hospitalization from the disease over 4 months among people aged 50 and older.

The major gain in preventing hospitalizations occurs with the first vaccination series and then wanes, the CDC said.

It appears that one hospitalization is prevented for every 135 people who get the first round of COVID-19 vaccinations. But it takes 674 people getting a first booster dose to prevent one hospitalization. A second booster prevents one hospitalization for every 1,205 people vaccinated.

Dr. Bell said she’s concerned about considering additional doses for “smaller and smaller return and creating an impression that we don’t have a very effective vaccination program,” even though the CDC’s data show a clear benefit.
 

Reasons to get a second booster

Elisha Hall, PhD, RD, of the CDC presented slides with some factors to help determine the urgency for a person to get a second booster:

• Having certain underlying medical conditions that increase the risk of severe COVID-19 illness.
• Being moderately or severely immunocompromised.
• Living with someone who is immunocompromised, at increased risk for severe disease, or who cannot be vaccinated because of age or contraindication.
• Being at increased risk of exposure to SARS-CoV-2, the virus that causes COVID-19, such as through occupational, institutional, or other activities (e.g., travel or large gatherings).
• Living or working in an area where there is a medium or high level of COVID-19 in the community.

In contrast, people might want to wait if they had been infected with SARS-CoV-2 within the past 3 months, Dr. Hall said in her presentation. Another reason for delay might be a concern that a booster dose may be more important later in the year.

The experts also addressed public confusion over boosters. For the Pfizer and Moderna mRNA vaccines, a second booster is a fourth dose, but for those who received the one-shot J&J vaccine, the second booster is a third dose.

Going forward, it may be easier to refer to subsequent doses as “annual boosters,” the CDC’s Sara Oliver, MD, MSPH, told the panel. It will be important to keep language about subsequent vaccinations clear and easy for the public to follow, she said.

Dr. Oliver also said there’s already been a drop-off in the acceptance of second rounds of COVID-19 vaccinations. CDC data show that 77% of people in the United States have had at least one dose of a COVID-19 vaccine, but only 66% of the population is fully vaccinated, and only 45% have had a first booster dose.

In her presentation, Dr. Oliver said the top priority in COVID-19 vaccination efforts remains initial vaccinations for people who haven’t gotten them.
 

Kids younger than 5

During the public comment session of the CDC meeting, several people called on the FDA to move quickly to expand authorization of COVID-19 vaccines to children aged 5 years and younger.

“We know that many parents and caregivers and health care providers are anxious to have COVID vaccines available” for young children, said Doran Fink, MD, PhD, a deputy director of the FDA’s vaccines division.

He said the agency is working to be ready to authorize the shots for young children while it awaits research results from the manufacturers.

A version of this article first appeared on WebMD.com.

About 30% of COVID-19 patients developed the condition known as long COVID, University of California, Los Angeles, researchers said in a study published in the Journal of General Internal Medicine.

The UCLA researchers studied 1,038 people enrolled in the UCLA COVID Ambulatory Program between April 2020 and February 2021 and found that 309 developed long COVID.

A long-COVID diagnosis came if a patient answering a questionnaire reported persistent symptoms 60-90 days after they were infected or hospitalized. The most persistent symptoms were fatigue (31%) and shortness of breath (15%) in hospitalized participants. Among outpatients, 16% reported losing sense of smell.

The study’s findings differ from earlier research. The University of California, Davis, for example, estimated that 10% of COVID-19 patients develop long-haul symptoms. A 2021 study from Penn State University found that more than half of worldwide COVID-19 patients would develop long COVID.

Part of the discrepancy can blamed on the fact there is no official, widely accepted definition of long COVID. The Centers for Disease Control and Prevention has said it means patients who experience “new, returning, or ongoing health problems 4 or more weeks after an initial infection” the coronavirus. The UCLA study, meanwhile, included patients still having symptoms 60-90 days after infection.

Still, the UCLA research team looked at demographics and clinical characteristics in an attempt to develop effective treatments.

People with a history of hospitalization, diabetes, and higher body mass index were most likely to develop long COVID, the researchers said. The kind of insurance the patients had also seemed to be a factor, though the researchers didn’t offer a reason why.

“Surprisingly, patients with commercial insurance had double the likelihood of developing [long COVID] compared to patients with Medicaid,” they wrote. “This association will be important to explore further to understand if insurance status in this group is representing unmeasured demographic factors or exposures.”

Older age and socioeconomic status were not associated with long COVID in the study – a surprise because those characteristics are often linked with severe illness and higher risk of death from COVID-19.

Weaknesses in the study included the subjective nature of how patients rated their symptoms and the limited number of symptoms evaluated.

“This study illustrates the need to follow diverse patient populations ... to understand the long COVID disease trajectory and evaluate how individual factors such as preexisting comorbidities, sociodemographic factors, vaccination status and virus variant type affect type and persistence of long COVID symptoms,” said Sun Yoo, MD, health sciences assistant clinical professor at UCLA.

A version of this article first appeared on WebMD.com.

About 30% of COVID-19 patients developed the condition known as long COVID, University of California, Los Angeles, researchers said in a study published in the Journal of General Internal Medicine.

The UCLA researchers studied 1,038 people enrolled in the UCLA COVID Ambulatory Program between April 2020 and February 2021 and found that 309 developed long COVID.

A long-COVID diagnosis came if a patient answering a questionnaire reported persistent symptoms 60-90 days after they were infected or hospitalized. The most persistent symptoms were fatigue (31%) and shortness of breath (15%) in hospitalized participants. Among outpatients, 16% reported losing sense of smell.

The study’s findings differ from earlier research. The University of California, Davis, for example, estimated that 10% of COVID-19 patients develop long-haul symptoms. A 2021 study from Penn State University found that more than half of worldwide COVID-19 patients would develop long COVID.

Part of the discrepancy can blamed on the fact there is no official, widely accepted definition of long COVID. The Centers for Disease Control and Prevention has said it means patients who experience “new, returning, or ongoing health problems 4 or more weeks after an initial infection” the coronavirus. The UCLA study, meanwhile, included patients still having symptoms 60-90 days after infection.

Still, the UCLA research team looked at demographics and clinical characteristics in an attempt to develop effective treatments.

People with a history of hospitalization, diabetes, and higher body mass index were most likely to develop long COVID, the researchers said. The kind of insurance the patients had also seemed to be a factor, though the researchers didn’t offer a reason why.

“Surprisingly, patients with commercial insurance had double the likelihood of developing [long COVID] compared to patients with Medicaid,” they wrote. “This association will be important to explore further to understand if insurance status in this group is representing unmeasured demographic factors or exposures.”

Older age and socioeconomic status were not associated with long COVID in the study – a surprise because those characteristics are often linked with severe illness and higher risk of death from COVID-19.

Weaknesses in the study included the subjective nature of how patients rated their symptoms and the limited number of symptoms evaluated.

“This study illustrates the need to follow diverse patient populations ... to understand the long COVID disease trajectory and evaluate how individual factors such as preexisting comorbidities, sociodemographic factors, vaccination status and virus variant type affect type and persistence of long COVID symptoms,” said Sun Yoo, MD, health sciences assistant clinical professor at UCLA.

A version of this article first appeared on WebMD.com.

About 30% of COVID-19 patients developed the condition known as long COVID, University of California, Los Angeles, researchers said in a study published in the Journal of General Internal Medicine.

The UCLA researchers studied 1,038 people enrolled in the UCLA COVID Ambulatory Program between April 2020 and February 2021 and found that 309 developed long COVID.

A long-COVID diagnosis came if a patient answering a questionnaire reported persistent symptoms 60-90 days after they were infected or hospitalized. The most persistent symptoms were fatigue (31%) and shortness of breath (15%) in hospitalized participants. Among outpatients, 16% reported losing sense of smell.

The study’s findings differ from earlier research. The University of California, Davis, for example, estimated that 10% of COVID-19 patients develop long-haul symptoms. A 2021 study from Penn State University found that more than half of worldwide COVID-19 patients would develop long COVID.

Part of the discrepancy can blamed on the fact there is no official, widely accepted definition of long COVID. The Centers for Disease Control and Prevention has said it means patients who experience “new, returning, or ongoing health problems 4 or more weeks after an initial infection” the coronavirus. The UCLA study, meanwhile, included patients still having symptoms 60-90 days after infection.

Still, the UCLA research team looked at demographics and clinical characteristics in an attempt to develop effective treatments.

People with a history of hospitalization, diabetes, and higher body mass index were most likely to develop long COVID, the researchers said. The kind of insurance the patients had also seemed to be a factor, though the researchers didn’t offer a reason why.

“Surprisingly, patients with commercial insurance had double the likelihood of developing [long COVID] compared to patients with Medicaid,” they wrote. “This association will be important to explore further to understand if insurance status in this group is representing unmeasured demographic factors or exposures.”

Older age and socioeconomic status were not associated with long COVID in the study – a surprise because those characteristics are often linked with severe illness and higher risk of death from COVID-19.

Weaknesses in the study included the subjective nature of how patients rated their symptoms and the limited number of symptoms evaluated.

“This study illustrates the need to follow diverse patient populations ... to understand the long COVID disease trajectory and evaluate how individual factors such as preexisting comorbidities, sociodemographic factors, vaccination status and virus variant type affect type and persistence of long COVID symptoms,” said Sun Yoo, MD, health sciences assistant clinical professor at UCLA.

A version of this article first appeared on WebMD.com.

Peripheral muscle fatigue was the most common cause of exercise limitation in patients recovered from COVID-19 regardless of disease severity, in a study of nearly 300 individuals.

The source and magnitude of exercise intolerance in post–COVID-19 patients has not been well studied, said Mauricio Milani, MD, of Fitcordis Exercise Medicine Clinic, Brasilia, Brazil, in a presentation at the annual congress of the European Association of Preventive Cardiology.

Midas Anim/Shutterstock

To assess exercise intolerance, the researchers performed cardiopulmonary exercise testing (CPET) on 144 adults who had recovered from COVID-19 and 144 matched controls who had not had COVID-19. The average age of the participants was 43 years, and 57% were male. COVID-19 was defined as mild, moderate, or severe in 60%, 21%, and 19% of the cases, respectively.

Residual symptoms were present in 41% of cases. CPET was performed at roughly 14 weeks after disease onset.

Among the COVID-19 patients, most of the CPET limitations (92%) were caused by muscle fatigue; cardiovascular limitations were noted in 2%, and pulmonary limitations were noted in 6%.

Data from the post-COVID CPET showed differences in peak oxygen consumption, as well as the first and second ventilatory thresholds (VT1 and VT2) between COVID-19 patients and controls, and with lower values related to higher illness severities, Dr. Milani said. Heart rate also varied according to illness severity, with lower values significantly related to higher illness severities and significant differences between COVID patients and controls.

A total of 42 individuals with COVID-19 had previous CPET data for comparison (27 with mild disease and 15 with moderate or severe disease), Dr. Milani said. In the subgroup with mild disease, the only significant difference in CPET results before and after COVID-19 was peak speed. In the moderate/severe group, the researchers observed higher reductions in peak speed and also reductions in oxygen consumption at peak and thresholds.

However, peak oxygen flows were not different before and after COVID-19 in either the mild or moderate/severe subgroups, Dr. Milani said.

The study findings were limited in part by the relatively small study population; however, the results indicate that peripheral muscle fatigue is the primary etiology in exercise limitation in post–COVID-19 patients.

“Our data suggest that treatment should emphasize comprehensive rehabilitation programs, including aerobic and muscle strengthening components,” Dr. Milani concluded.

COVID challenges remain unclear

“After COVID, patients often display a postviral syndrome with a wide range of symptoms,” Matthew Martinez, MD, a sports cardiologist at the Atlantic Health System in Morristown, N.J., in an interview said. “These conditions frequently lead to a sense of tiredness and weakness, pain, difficulty concentrating, and headaches that linger after the viral infection has cleared,” and these symptoms may continue for weeks.

However, this scenario is not unique to COVID-19: “This study confirms the importance of muscle fatigue in recovery,” said Dr. Martinez. “Recovery from viral illness requires hydration, sleep and slow progression return to exercise.” Consequently, Dr. Martinez said he was not surprised by the current study findings.

The take-home message for clinicians is to be aware that COVID-19 can have postviral syndrome, as is common after other infections, Dr. Martinez noted. The findings provide a starting point for discussing concerns with patients and explaining that a slow return to normal with usual care is expected. “Time to recovery will vary by individual,” he said. “Additional research is needed to identify which specific therapies are most important to help reduce time to recovery, and what new therapies could be developed to help facilitate muscle fatigue recovery and reduce time needed to recover.”

The study was supported by CAPES and CNPq. Dr. Milani had no financial conflicts to disclose. Dr. Martinez had no financial conflicts to disclose.

Peripheral muscle fatigue was the most common cause of exercise limitation in patients recovered from COVID-19 regardless of disease severity, in a study of nearly 300 individuals.

The source and magnitude of exercise intolerance in post–COVID-19 patients has not been well studied, said Mauricio Milani, MD, of Fitcordis Exercise Medicine Clinic, Brasilia, Brazil, in a presentation at the annual congress of the European Association of Preventive Cardiology.

Midas Anim/Shutterstock

To assess exercise intolerance, the researchers performed cardiopulmonary exercise testing (CPET) on 144 adults who had recovered from COVID-19 and 144 matched controls who had not had COVID-19. The average age of the participants was 43 years, and 57% were male. COVID-19 was defined as mild, moderate, or severe in 60%, 21%, and 19% of the cases, respectively.

Residual symptoms were present in 41% of cases. CPET was performed at roughly 14 weeks after disease onset.

Among the COVID-19 patients, most of the CPET limitations (92%) were caused by muscle fatigue; cardiovascular limitations were noted in 2%, and pulmonary limitations were noted in 6%.

Data from the post-COVID CPET showed differences in peak oxygen consumption, as well as the first and second ventilatory thresholds (VT1 and VT2) between COVID-19 patients and controls, and with lower values related to higher illness severities, Dr. Milani said. Heart rate also varied according to illness severity, with lower values significantly related to higher illness severities and significant differences between COVID patients and controls.

A total of 42 individuals with COVID-19 had previous CPET data for comparison (27 with mild disease and 15 with moderate or severe disease), Dr. Milani said. In the subgroup with mild disease, the only significant difference in CPET results before and after COVID-19 was peak speed. In the moderate/severe group, the researchers observed higher reductions in peak speed and also reductions in oxygen consumption at peak and thresholds.

However, peak oxygen flows were not different before and after COVID-19 in either the mild or moderate/severe subgroups, Dr. Milani said.

The study findings were limited in part by the relatively small study population; however, the results indicate that peripheral muscle fatigue is the primary etiology in exercise limitation in post–COVID-19 patients.

“Our data suggest that treatment should emphasize comprehensive rehabilitation programs, including aerobic and muscle strengthening components,” Dr. Milani concluded.

COVID challenges remain unclear

“After COVID, patients often display a postviral syndrome with a wide range of symptoms,” Matthew Martinez, MD, a sports cardiologist at the Atlantic Health System in Morristown, N.J., in an interview said. “These conditions frequently lead to a sense of tiredness and weakness, pain, difficulty concentrating, and headaches that linger after the viral infection has cleared,” and these symptoms may continue for weeks.

However, this scenario is not unique to COVID-19: “This study confirms the importance of muscle fatigue in recovery,” said Dr. Martinez. “Recovery from viral illness requires hydration, sleep and slow progression return to exercise.” Consequently, Dr. Martinez said he was not surprised by the current study findings.

The take-home message for clinicians is to be aware that COVID-19 can have postviral syndrome, as is common after other infections, Dr. Martinez noted. The findings provide a starting point for discussing concerns with patients and explaining that a slow return to normal with usual care is expected. “Time to recovery will vary by individual,” he said. “Additional research is needed to identify which specific therapies are most important to help reduce time to recovery, and what new therapies could be developed to help facilitate muscle fatigue recovery and reduce time needed to recover.”

The study was supported by CAPES and CNPq. Dr. Milani had no financial conflicts to disclose. Dr. Martinez had no financial conflicts to disclose.

Peripheral muscle fatigue was the most common cause of exercise limitation in patients recovered from COVID-19 regardless of disease severity, in a study of nearly 300 individuals.

The source and magnitude of exercise intolerance in post–COVID-19 patients has not been well studied, said Mauricio Milani, MD, of Fitcordis Exercise Medicine Clinic, Brasilia, Brazil, in a presentation at the annual congress of the European Association of Preventive Cardiology.

Midas Anim/Shutterstock

To assess exercise intolerance, the researchers performed cardiopulmonary exercise testing (CPET) on 144 adults who had recovered from COVID-19 and 144 matched controls who had not had COVID-19. The average age of the participants was 43 years, and 57% were male. COVID-19 was defined as mild, moderate, or severe in 60%, 21%, and 19% of the cases, respectively.

Residual symptoms were present in 41% of cases. CPET was performed at roughly 14 weeks after disease onset.

Among the COVID-19 patients, most of the CPET limitations (92%) were caused by muscle fatigue; cardiovascular limitations were noted in 2%, and pulmonary limitations were noted in 6%.

Data from the post-COVID CPET showed differences in peak oxygen consumption, as well as the first and second ventilatory thresholds (VT1 and VT2) between COVID-19 patients and controls, and with lower values related to higher illness severities, Dr. Milani said. Heart rate also varied according to illness severity, with lower values significantly related to higher illness severities and significant differences between COVID patients and controls.

A total of 42 individuals with COVID-19 had previous CPET data for comparison (27 with mild disease and 15 with moderate or severe disease), Dr. Milani said. In the subgroup with mild disease, the only significant difference in CPET results before and after COVID-19 was peak speed. In the moderate/severe group, the researchers observed higher reductions in peak speed and also reductions in oxygen consumption at peak and thresholds.

However, peak oxygen flows were not different before and after COVID-19 in either the mild or moderate/severe subgroups, Dr. Milani said.

The study findings were limited in part by the relatively small study population; however, the results indicate that peripheral muscle fatigue is the primary etiology in exercise limitation in post–COVID-19 patients.

“Our data suggest that treatment should emphasize comprehensive rehabilitation programs, including aerobic and muscle strengthening components,” Dr. Milani concluded.

COVID challenges remain unclear

“After COVID, patients often display a postviral syndrome with a wide range of symptoms,” Matthew Martinez, MD, a sports cardiologist at the Atlantic Health System in Morristown, N.J., in an interview said. “These conditions frequently lead to a sense of tiredness and weakness, pain, difficulty concentrating, and headaches that linger after the viral infection has cleared,” and these symptoms may continue for weeks.

However, this scenario is not unique to COVID-19: “This study confirms the importance of muscle fatigue in recovery,” said Dr. Martinez. “Recovery from viral illness requires hydration, sleep and slow progression return to exercise.” Consequently, Dr. Martinez said he was not surprised by the current study findings.

The take-home message for clinicians is to be aware that COVID-19 can have postviral syndrome, as is common after other infections, Dr. Martinez noted. The findings provide a starting point for discussing concerns with patients and explaining that a slow return to normal with usual care is expected. “Time to recovery will vary by individual,” he said. “Additional research is needed to identify which specific therapies are most important to help reduce time to recovery, and what new therapies could be developed to help facilitate muscle fatigue recovery and reduce time needed to recover.”

The study was supported by CAPES and CNPq. Dr. Milani had no financial conflicts to disclose. Dr. Martinez had no financial conflicts to disclose.

During the first year of the pandemic, at least four people in Michigan were infected with a coronavirus variant that has been found in mink.

The cluster, which previously included three cases, marks the first known instance of likely animal-to-human “spillover” of the virus in the United States, according to the New York Times. All four people fully recovered.

Two of the infected people were employees of a mink farm in Michigan that had an outbreak in October 2020. The other two people didn’t have known links to the farm, which may mean that the coronavirus variant among mink may have been circulating more widely among residents in that area during that time.

Virus samples from all four people contained two mutations that may show signs of an adaptation to mink. The mutations have also been documented in farmed mink in Europe and people with connections to those farms.

“This, in addition to the mink farmworkers testing positive for COVID-19 after the mink herd had begun experiencing illness and increased mortality, suggests that the most likely hypothesis is that the workers were infected after contact with mink on the farm,” Casey Barton Behravesh, DVM, who directs the Centers for Disease Control and Prevention’s One Health Office, told the newspaper.

But researchers are unable to prove the cause, she noted.

“Because there are few genetic sequences available from the communities around the farm, it is impossible to know for sure whether the mutations came from mink on the farm or were already circulating in the community,” she said.

In August 2020, the U.S. Department of Agriculture announced the first confirmed COVID-19 case in mink at farms in Utah, followed by a case in Wisconsin. Worldwide, the coronavirus has been detected in mink on farms in the Netherlands, Denmark, Poland, and Spain.

In early October 2020, Michigan officials announced that the coronavirus had been detected in mink on a local farm. Several of the animals had died. The CDC helped to investigate the outbreak by collecting samples from animals, farmworkers, and residents in the community.

By March 2021, the CDC had updated its website to note that a “small number of people” had contracted a coronavirus variant that “contained unique mink-related mutations.”

In April 2021, the Detroit Free Press and the Documenting COVID-19 project first reported on the first three cases – two farmworkers and a taxidermist who didn’t have a connection to the mink farm. This week, the news outlets reported an update that the fourth case was the taxidermist’s wife.

Earlier this month, National Geographic first reported on the fourth human case based on government documents about the mink farm outbreak.

Overall, animal-to-human transmission is rare, but the CDC is continuing to monitor potential coronavirus cases in wildlife, livestock, and zoo animals for new variants and virus reservoirs, the Times reported.

“These results highlight the importance of routinely studying the genetic material of SARS-CoV-2 in susceptible animal populations like mink, as well as in people,” the CDC wrote.

A version of this article first appeared on WebMD.com.

During the first year of the pandemic, at least four people in Michigan were infected with a coronavirus variant that has been found in mink.

The cluster, which previously included three cases, marks the first known instance of likely animal-to-human “spillover” of the virus in the United States, according to the New York Times. All four people fully recovered.

Two of the infected people were employees of a mink farm in Michigan that had an outbreak in October 2020. The other two people didn’t have known links to the farm, which may mean that the coronavirus variant among mink may have been circulating more widely among residents in that area during that time.

Virus samples from all four people contained two mutations that may show signs of an adaptation to mink. The mutations have also been documented in farmed mink in Europe and people with connections to those farms.

“This, in addition to the mink farmworkers testing positive for COVID-19 after the mink herd had begun experiencing illness and increased mortality, suggests that the most likely hypothesis is that the workers were infected after contact with mink on the farm,” Casey Barton Behravesh, DVM, who directs the Centers for Disease Control and Prevention’s One Health Office, told the newspaper.

But researchers are unable to prove the cause, she noted.

“Because there are few genetic sequences available from the communities around the farm, it is impossible to know for sure whether the mutations came from mink on the farm or were already circulating in the community,” she said.

In August 2020, the U.S. Department of Agriculture announced the first confirmed COVID-19 case in mink at farms in Utah, followed by a case in Wisconsin. Worldwide, the coronavirus has been detected in mink on farms in the Netherlands, Denmark, Poland, and Spain.

In early October 2020, Michigan officials announced that the coronavirus had been detected in mink on a local farm. Several of the animals had died. The CDC helped to investigate the outbreak by collecting samples from animals, farmworkers, and residents in the community.

By March 2021, the CDC had updated its website to note that a “small number of people” had contracted a coronavirus variant that “contained unique mink-related mutations.”

In April 2021, the Detroit Free Press and the Documenting COVID-19 project first reported on the first three cases – two farmworkers and a taxidermist who didn’t have a connection to the mink farm. This week, the news outlets reported an update that the fourth case was the taxidermist’s wife.

Earlier this month, National Geographic first reported on the fourth human case based on government documents about the mink farm outbreak.

Overall, animal-to-human transmission is rare, but the CDC is continuing to monitor potential coronavirus cases in wildlife, livestock, and zoo animals for new variants and virus reservoirs, the Times reported.

“These results highlight the importance of routinely studying the genetic material of SARS-CoV-2 in susceptible animal populations like mink, as well as in people,” the CDC wrote.

A version of this article first appeared on WebMD.com.

During the first year of the pandemic, at least four people in Michigan were infected with a coronavirus variant that has been found in mink.

The cluster, which previously included three cases, marks the first known instance of likely animal-to-human “spillover” of the virus in the United States, according to the New York Times. All four people fully recovered.

Two of the infected people were employees of a mink farm in Michigan that had an outbreak in October 2020. The other two people didn’t have known links to the farm, which may mean that the coronavirus variant among mink may have been circulating more widely among residents in that area during that time.

Virus samples from all four people contained two mutations that may show signs of an adaptation to mink. The mutations have also been documented in farmed mink in Europe and people with connections to those farms.

“This, in addition to the mink farmworkers testing positive for COVID-19 after the mink herd had begun experiencing illness and increased mortality, suggests that the most likely hypothesis is that the workers were infected after contact with mink on the farm,” Casey Barton Behravesh, DVM, who directs the Centers for Disease Control and Prevention’s One Health Office, told the newspaper.

But researchers are unable to prove the cause, she noted.

“Because there are few genetic sequences available from the communities around the farm, it is impossible to know for sure whether the mutations came from mink on the farm or were already circulating in the community,” she said.

In August 2020, the U.S. Department of Agriculture announced the first confirmed COVID-19 case in mink at farms in Utah, followed by a case in Wisconsin. Worldwide, the coronavirus has been detected in mink on farms in the Netherlands, Denmark, Poland, and Spain.

In early October 2020, Michigan officials announced that the coronavirus had been detected in mink on a local farm. Several of the animals had died. The CDC helped to investigate the outbreak by collecting samples from animals, farmworkers, and residents in the community.

By March 2021, the CDC had updated its website to note that a “small number of people” had contracted a coronavirus variant that “contained unique mink-related mutations.”

In April 2021, the Detroit Free Press and the Documenting COVID-19 project first reported on the first three cases – two farmworkers and a taxidermist who didn’t have a connection to the mink farm. This week, the news outlets reported an update that the fourth case was the taxidermist’s wife.

Earlier this month, National Geographic first reported on the fourth human case based on government documents about the mink farm outbreak.

Overall, animal-to-human transmission is rare, but the CDC is continuing to monitor potential coronavirus cases in wildlife, livestock, and zoo animals for new variants and virus reservoirs, the Times reported.

“These results highlight the importance of routinely studying the genetic material of SARS-CoV-2 in susceptible animal populations like mink, as well as in people,” the CDC wrote.

A version of this article first appeared on WebMD.com.