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First Human Bird Flu Death Confirmed in US; Overall Risk Remains Low
The first human patient in the United States with a confirmed case of avian influenza has died, according to a press release from the Louisiana Department of Health. The individual was older than 65 years and had underlying medical conditions and remains the only known human case in the state.
The patient contracted highly pathogenic avian influenza, also known as H5N1, through exposure to wild birds and a noncommercial backyard flock, according to the release.
The Centers for Disease Control and Prevention (CDC) conducted genetic sequencing of specimens of the virus collected from the Louisiana patient. The agency compared the sequences with sequences from dairy cows, wild birds, and poultry in various areas of the United States that were infected with the H5N1 virus.
The Louisiana patient was infected with the D1.1 genotype of the H5N1 virus. Although D1.1 is related to other D1.1 viruses found in recent human cases in Washington State and British Columbia, Canada, it is distinct from the widely spreading B3.13 genotype that has caused H5N1 outbreaks in dairy cows, poultry, and other animals and has been linked to sporadic human cases in the United States, according to the CDC.
Despite evidence of some changes in the virus between the Louisiana patient and samples from poultry on the patient’s property, “these changes would be more concerning if found in animal hosts or in early stages of infection,” according to the CDC. The CDC and the Louisiana Department of Health are conducting additional sequencing to facilitate further analysis.
In the meantime, the risk to the general public for H5N1 remains low, but individuals who work with or have recreational exposure to birds, poultry, or cows remain at increased risk.
The CDC and the Louisiana Department of Health advise individuals to reduce the risk for H5N1 exposure by avoiding direct contact with wild birds or other animals infected or possibly infected with the virus, avoiding any contact with dead animals, and keeping pets away from sick or dead animals and their feces. Additional safety measures include avoiding uncooked food products such as unpasteurized raw milk or cheese from animals with suspected or confirmed infections and reporting sick or dead birds or animals to the US Department of Agriculture by calling 1-866-536-7593 or the Louisiana Department of Agriculture and Forestry Diagnostic Lab by calling 318-927-3441.
The CDC advises clinicians to consider H5N1 in patients presenting with conjunctivitis or signs of acute respiratory illness and a history of high-risk exposure, including handling sick or dead animals, notably birds and livestock, within 10 days before the onset of symptoms. Other risk factors include consuming uncooked or undercooked food, direct contact with areas contaminated with feces, direct contact with unpasteurized milk or other dairy products or with parts of potentially infected animals, and prolonged exposure to infected animals in a confined space.
Clinical symptoms also may include gastrointestinal complaints such as diarrhea, as well as fatigue, arthralgia, and headache. Patients with more severe H5N1 may experience shortness of breath, altered mental state, and seizures, and serious complications of the virus include pneumonia, acute respiratory distress syndrome, multiorgan failure, and sepsis, according to the CDC.
Clinicians who suspect H5N1 cases should contact their local public health departments. The CDC offers additional advice on evaluating and managing patients with novel influenza A viruses.
A Clinician’s Take
“Some symptoms of avian flu include fever, cough, sore throat, runny nose, fatigue, body aches or eye redness or irritation,” Shirin A. Mazumder, MD, associate professor and infectious disease specialist at The University of Tennessee Health Science Center, Memphis, said in an interview. “The timing to the development of symptoms after exposure is typically within 10 days. Avian influenza should be considered when individuals develop symptoms with a relevant exposure history,” she said.
Whenever possible, avoidance of sick or dead birds and other animals is ideal, but for those who must have contact with sick or dead birds, poultry, or other animals, personal protective equipment (PPE) including a respirator, goggles, and disposable gloves is recommended, said Mazumder.
“For those working in high-exposure settings, additional PPE including boots or boot covers, hair cover, and fluid-resistant coveralls are recommended,” she said. “Other protective measures include avoiding touching surfaces or materials contaminated with feces, mucus, and saliva from infected animals and avoid[ing] the consumption of raw milk, raw milk products, and undercooked meat from infected animals,” she added.
Hunters handling wild game should dress birds in the field, practice good hand hygiene, and use a respirator or well-fitting mask and gloves when handling the animals to help prevent disease, said Mazumder.
In addition, those working with confirmed or suspected H5N1 cases should monitor themselves for symptoms, said Mazumder. “Those who become ill within 10 days of exposure to an infected animal or source should isolate from household members and avoid going to work or school until infection is excluded. It is important to reach out to a healthcare professional if you think you may have been exposed or if you think you are infected,” she said.
There is no currently available vaccine for H5N1 infection, but oseltamivir can be used for chemoprophylaxis and treatment, said Mazumder. “The seasonal flu vaccine does not protect against avian influenza; however, it is still important to ensure that you are up to date on the latest flu vaccine to prevent the possibility of a coinfection with seasonal flu and avian flu,” she emphasized.
More research is needed to better understand how the influenza virus is transmitted, said Mazumder. “The potential for the virus to evolve and mutate, and how it affects different hosts, are all factors that can impact public health decisions,” she said. “In addition, further research into finding a vaccine and improving surveillance methods are necessary for disease prevention,” she said.
Mazumder had no financial conflicts to disclose.
A version of this article appeared on Medscape.com.
The first human patient in the United States with a confirmed case of avian influenza has died, according to a press release from the Louisiana Department of Health. The individual was older than 65 years and had underlying medical conditions and remains the only known human case in the state.
The patient contracted highly pathogenic avian influenza, also known as H5N1, through exposure to wild birds and a noncommercial backyard flock, according to the release.
The Centers for Disease Control and Prevention (CDC) conducted genetic sequencing of specimens of the virus collected from the Louisiana patient. The agency compared the sequences with sequences from dairy cows, wild birds, and poultry in various areas of the United States that were infected with the H5N1 virus.
The Louisiana patient was infected with the D1.1 genotype of the H5N1 virus. Although D1.1 is related to other D1.1 viruses found in recent human cases in Washington State and British Columbia, Canada, it is distinct from the widely spreading B3.13 genotype that has caused H5N1 outbreaks in dairy cows, poultry, and other animals and has been linked to sporadic human cases in the United States, according to the CDC.
Despite evidence of some changes in the virus between the Louisiana patient and samples from poultry on the patient’s property, “these changes would be more concerning if found in animal hosts or in early stages of infection,” according to the CDC. The CDC and the Louisiana Department of Health are conducting additional sequencing to facilitate further analysis.
In the meantime, the risk to the general public for H5N1 remains low, but individuals who work with or have recreational exposure to birds, poultry, or cows remain at increased risk.
The CDC and the Louisiana Department of Health advise individuals to reduce the risk for H5N1 exposure by avoiding direct contact with wild birds or other animals infected or possibly infected with the virus, avoiding any contact with dead animals, and keeping pets away from sick or dead animals and their feces. Additional safety measures include avoiding uncooked food products such as unpasteurized raw milk or cheese from animals with suspected or confirmed infections and reporting sick or dead birds or animals to the US Department of Agriculture by calling 1-866-536-7593 or the Louisiana Department of Agriculture and Forestry Diagnostic Lab by calling 318-927-3441.
The CDC advises clinicians to consider H5N1 in patients presenting with conjunctivitis or signs of acute respiratory illness and a history of high-risk exposure, including handling sick or dead animals, notably birds and livestock, within 10 days before the onset of symptoms. Other risk factors include consuming uncooked or undercooked food, direct contact with areas contaminated with feces, direct contact with unpasteurized milk or other dairy products or with parts of potentially infected animals, and prolonged exposure to infected animals in a confined space.
Clinical symptoms also may include gastrointestinal complaints such as diarrhea, as well as fatigue, arthralgia, and headache. Patients with more severe H5N1 may experience shortness of breath, altered mental state, and seizures, and serious complications of the virus include pneumonia, acute respiratory distress syndrome, multiorgan failure, and sepsis, according to the CDC.
Clinicians who suspect H5N1 cases should contact their local public health departments. The CDC offers additional advice on evaluating and managing patients with novel influenza A viruses.
A Clinician’s Take
“Some symptoms of avian flu include fever, cough, sore throat, runny nose, fatigue, body aches or eye redness or irritation,” Shirin A. Mazumder, MD, associate professor and infectious disease specialist at The University of Tennessee Health Science Center, Memphis, said in an interview. “The timing to the development of symptoms after exposure is typically within 10 days. Avian influenza should be considered when individuals develop symptoms with a relevant exposure history,” she said.
Whenever possible, avoidance of sick or dead birds and other animals is ideal, but for those who must have contact with sick or dead birds, poultry, or other animals, personal protective equipment (PPE) including a respirator, goggles, and disposable gloves is recommended, said Mazumder.
“For those working in high-exposure settings, additional PPE including boots or boot covers, hair cover, and fluid-resistant coveralls are recommended,” she said. “Other protective measures include avoiding touching surfaces or materials contaminated with feces, mucus, and saliva from infected animals and avoid[ing] the consumption of raw milk, raw milk products, and undercooked meat from infected animals,” she added.
Hunters handling wild game should dress birds in the field, practice good hand hygiene, and use a respirator or well-fitting mask and gloves when handling the animals to help prevent disease, said Mazumder.
In addition, those working with confirmed or suspected H5N1 cases should monitor themselves for symptoms, said Mazumder. “Those who become ill within 10 days of exposure to an infected animal or source should isolate from household members and avoid going to work or school until infection is excluded. It is important to reach out to a healthcare professional if you think you may have been exposed or if you think you are infected,” she said.
There is no currently available vaccine for H5N1 infection, but oseltamivir can be used for chemoprophylaxis and treatment, said Mazumder. “The seasonal flu vaccine does not protect against avian influenza; however, it is still important to ensure that you are up to date on the latest flu vaccine to prevent the possibility of a coinfection with seasonal flu and avian flu,” she emphasized.
More research is needed to better understand how the influenza virus is transmitted, said Mazumder. “The potential for the virus to evolve and mutate, and how it affects different hosts, are all factors that can impact public health decisions,” she said. “In addition, further research into finding a vaccine and improving surveillance methods are necessary for disease prevention,” she said.
Mazumder had no financial conflicts to disclose.
A version of this article appeared on Medscape.com.
The first human patient in the United States with a confirmed case of avian influenza has died, according to a press release from the Louisiana Department of Health. The individual was older than 65 years and had underlying medical conditions and remains the only known human case in the state.
The patient contracted highly pathogenic avian influenza, also known as H5N1, through exposure to wild birds and a noncommercial backyard flock, according to the release.
The Centers for Disease Control and Prevention (CDC) conducted genetic sequencing of specimens of the virus collected from the Louisiana patient. The agency compared the sequences with sequences from dairy cows, wild birds, and poultry in various areas of the United States that were infected with the H5N1 virus.
The Louisiana patient was infected with the D1.1 genotype of the H5N1 virus. Although D1.1 is related to other D1.1 viruses found in recent human cases in Washington State and British Columbia, Canada, it is distinct from the widely spreading B3.13 genotype that has caused H5N1 outbreaks in dairy cows, poultry, and other animals and has been linked to sporadic human cases in the United States, according to the CDC.
Despite evidence of some changes in the virus between the Louisiana patient and samples from poultry on the patient’s property, “these changes would be more concerning if found in animal hosts or in early stages of infection,” according to the CDC. The CDC and the Louisiana Department of Health are conducting additional sequencing to facilitate further analysis.
In the meantime, the risk to the general public for H5N1 remains low, but individuals who work with or have recreational exposure to birds, poultry, or cows remain at increased risk.
The CDC and the Louisiana Department of Health advise individuals to reduce the risk for H5N1 exposure by avoiding direct contact with wild birds or other animals infected or possibly infected with the virus, avoiding any contact with dead animals, and keeping pets away from sick or dead animals and their feces. Additional safety measures include avoiding uncooked food products such as unpasteurized raw milk or cheese from animals with suspected or confirmed infections and reporting sick or dead birds or animals to the US Department of Agriculture by calling 1-866-536-7593 or the Louisiana Department of Agriculture and Forestry Diagnostic Lab by calling 318-927-3441.
The CDC advises clinicians to consider H5N1 in patients presenting with conjunctivitis or signs of acute respiratory illness and a history of high-risk exposure, including handling sick or dead animals, notably birds and livestock, within 10 days before the onset of symptoms. Other risk factors include consuming uncooked or undercooked food, direct contact with areas contaminated with feces, direct contact with unpasteurized milk or other dairy products or with parts of potentially infected animals, and prolonged exposure to infected animals in a confined space.
Clinical symptoms also may include gastrointestinal complaints such as diarrhea, as well as fatigue, arthralgia, and headache. Patients with more severe H5N1 may experience shortness of breath, altered mental state, and seizures, and serious complications of the virus include pneumonia, acute respiratory distress syndrome, multiorgan failure, and sepsis, according to the CDC.
Clinicians who suspect H5N1 cases should contact their local public health departments. The CDC offers additional advice on evaluating and managing patients with novel influenza A viruses.
A Clinician’s Take
“Some symptoms of avian flu include fever, cough, sore throat, runny nose, fatigue, body aches or eye redness or irritation,” Shirin A. Mazumder, MD, associate professor and infectious disease specialist at The University of Tennessee Health Science Center, Memphis, said in an interview. “The timing to the development of symptoms after exposure is typically within 10 days. Avian influenza should be considered when individuals develop symptoms with a relevant exposure history,” she said.
Whenever possible, avoidance of sick or dead birds and other animals is ideal, but for those who must have contact with sick or dead birds, poultry, or other animals, personal protective equipment (PPE) including a respirator, goggles, and disposable gloves is recommended, said Mazumder.
“For those working in high-exposure settings, additional PPE including boots or boot covers, hair cover, and fluid-resistant coveralls are recommended,” she said. “Other protective measures include avoiding touching surfaces or materials contaminated with feces, mucus, and saliva from infected animals and avoid[ing] the consumption of raw milk, raw milk products, and undercooked meat from infected animals,” she added.
Hunters handling wild game should dress birds in the field, practice good hand hygiene, and use a respirator or well-fitting mask and gloves when handling the animals to help prevent disease, said Mazumder.
In addition, those working with confirmed or suspected H5N1 cases should monitor themselves for symptoms, said Mazumder. “Those who become ill within 10 days of exposure to an infected animal or source should isolate from household members and avoid going to work or school until infection is excluded. It is important to reach out to a healthcare professional if you think you may have been exposed or if you think you are infected,” she said.
There is no currently available vaccine for H5N1 infection, but oseltamivir can be used for chemoprophylaxis and treatment, said Mazumder. “The seasonal flu vaccine does not protect against avian influenza; however, it is still important to ensure that you are up to date on the latest flu vaccine to prevent the possibility of a coinfection with seasonal flu and avian flu,” she emphasized.
More research is needed to better understand how the influenza virus is transmitted, said Mazumder. “The potential for the virus to evolve and mutate, and how it affects different hosts, are all factors that can impact public health decisions,” she said. “In addition, further research into finding a vaccine and improving surveillance methods are necessary for disease prevention,” she said.
Mazumder had no financial conflicts to disclose.
A version of this article appeared on Medscape.com.
Flu Shot Reminders Improve Use in Heart Attack Survivors
, showed the NUDGE FLU series of clinical trials.
Influenza has the potential to be a dangerous infection on its own, but it increases the risk for cardiovascular events among people with a history of heart attack, said the study’s lead author, Ankeet Bhatt, MD, a cardiologist at Kaiser Permanente San Francisco Medical Center, San Francisco.
“Yearly influenza vaccines help prevent influenza infection and, in patients with a heart attack, are potentially cardioprotective,” he said during his presentation at the American Heart Association (AHA) Scientific Sessions 2024 in Chicago. The NUDGE FLU results were simultaneously published online in JAMA Cardiology.
In Denmark, where the trials were conducted, about 80% of older adults get flu shots, but only about 40% of younger adults with chronic diseases do, Bhatt reported. In the United States, about 45% of adults and 55% of children received at least one dose of the flu vaccine in the 2023/24 flu season, according to the US Centers for Disease Control and Prevention (CDC).
The NUDGE FLU Trials
Bhatt and his colleagues conducted three related clinical trials during the 2022/23 and 2023/24 flu seasons: NUDGE-FLU and NUDGE-FLU-2 targeted older adults, whereas NUDGE-FLU-CHRONIC targeted younger adults with chronic diseases. Nearly 2 million people were involved in the three trials.
Participants were randomized to receive one of a series of different behavioral-science-informed letters, delivered through a government-run electronic communication system, or no reminder.
People who received any of the nudges had higher rates of vaccination; among heart attack survivors, there was a 1.8% improvement and among adults without a history of heart attack, there was a 1.3% improvement. But a nudge that explained the potential cardiovascular benefits of flu shots was even more effective, leading to a 3.9% increase among people with a history of heart attack and a 2% increase among those with no heart attack history.
“A simple sentence resulted in a durable improvement in the vaccination rate,” said Bhatt.
The effect was even greater among those who had not been vaccinated in the previous flu season. Among heart attack survivors, nearly 14% more people got the vaccine compared with just 1.5% more survivors who were previously vaccinated. And it was most effective among younger adults who had experienced a recent heart attack, resulting in a 26% increase.
“The impact was larger in patients with a history of acute myocardial infarction, in those who were vaccine-hesitant, and in younger people” — all groups with the most to gain from vaccination in terms of cardiovascular protection — Bhatt reported.
About 25% of people in the United States are unsure about whether to get a flu shot, said Orly Vardeny, PharmD, professor of medicine at the University of Minnesota Medical School in Minneapolis, who was not involved in the study. The fact that previously unvaccinated people were convinced by the nudges is reassuring. “That’s the group where this intervention is most likely to move the needle,” she said.
Around half of all people hospitalized for flu in the United States have cardiovascular disease, CDC data showed, so “even a small increase in the number of patients who get vaccinated has substantial public health benefits,” Vardeny said.
The NUDGE FLU series showed that nudges like this should be employed as a simple tool to improve vaccination rates, but the system would be much more difficult to implement in the United States, Bhatt said.
Denmark has a national health service and a preexisting government electronic communication system, whereas the US system is privately run and more fractured. It would be possible to make it work, he pointed out, but would take some effort.
A version of this article first appeared on Medscape.com.
, showed the NUDGE FLU series of clinical trials.
Influenza has the potential to be a dangerous infection on its own, but it increases the risk for cardiovascular events among people with a history of heart attack, said the study’s lead author, Ankeet Bhatt, MD, a cardiologist at Kaiser Permanente San Francisco Medical Center, San Francisco.
“Yearly influenza vaccines help prevent influenza infection and, in patients with a heart attack, are potentially cardioprotective,” he said during his presentation at the American Heart Association (AHA) Scientific Sessions 2024 in Chicago. The NUDGE FLU results were simultaneously published online in JAMA Cardiology.
In Denmark, where the trials were conducted, about 80% of older adults get flu shots, but only about 40% of younger adults with chronic diseases do, Bhatt reported. In the United States, about 45% of adults and 55% of children received at least one dose of the flu vaccine in the 2023/24 flu season, according to the US Centers for Disease Control and Prevention (CDC).
The NUDGE FLU Trials
Bhatt and his colleagues conducted three related clinical trials during the 2022/23 and 2023/24 flu seasons: NUDGE-FLU and NUDGE-FLU-2 targeted older adults, whereas NUDGE-FLU-CHRONIC targeted younger adults with chronic diseases. Nearly 2 million people were involved in the three trials.
Participants were randomized to receive one of a series of different behavioral-science-informed letters, delivered through a government-run electronic communication system, or no reminder.
People who received any of the nudges had higher rates of vaccination; among heart attack survivors, there was a 1.8% improvement and among adults without a history of heart attack, there was a 1.3% improvement. But a nudge that explained the potential cardiovascular benefits of flu shots was even more effective, leading to a 3.9% increase among people with a history of heart attack and a 2% increase among those with no heart attack history.
“A simple sentence resulted in a durable improvement in the vaccination rate,” said Bhatt.
The effect was even greater among those who had not been vaccinated in the previous flu season. Among heart attack survivors, nearly 14% more people got the vaccine compared with just 1.5% more survivors who were previously vaccinated. And it was most effective among younger adults who had experienced a recent heart attack, resulting in a 26% increase.
“The impact was larger in patients with a history of acute myocardial infarction, in those who were vaccine-hesitant, and in younger people” — all groups with the most to gain from vaccination in terms of cardiovascular protection — Bhatt reported.
About 25% of people in the United States are unsure about whether to get a flu shot, said Orly Vardeny, PharmD, professor of medicine at the University of Minnesota Medical School in Minneapolis, who was not involved in the study. The fact that previously unvaccinated people were convinced by the nudges is reassuring. “That’s the group where this intervention is most likely to move the needle,” she said.
Around half of all people hospitalized for flu in the United States have cardiovascular disease, CDC data showed, so “even a small increase in the number of patients who get vaccinated has substantial public health benefits,” Vardeny said.
The NUDGE FLU series showed that nudges like this should be employed as a simple tool to improve vaccination rates, but the system would be much more difficult to implement in the United States, Bhatt said.
Denmark has a national health service and a preexisting government electronic communication system, whereas the US system is privately run and more fractured. It would be possible to make it work, he pointed out, but would take some effort.
A version of this article first appeared on Medscape.com.
, showed the NUDGE FLU series of clinical trials.
Influenza has the potential to be a dangerous infection on its own, but it increases the risk for cardiovascular events among people with a history of heart attack, said the study’s lead author, Ankeet Bhatt, MD, a cardiologist at Kaiser Permanente San Francisco Medical Center, San Francisco.
“Yearly influenza vaccines help prevent influenza infection and, in patients with a heart attack, are potentially cardioprotective,” he said during his presentation at the American Heart Association (AHA) Scientific Sessions 2024 in Chicago. The NUDGE FLU results were simultaneously published online in JAMA Cardiology.
In Denmark, where the trials were conducted, about 80% of older adults get flu shots, but only about 40% of younger adults with chronic diseases do, Bhatt reported. In the United States, about 45% of adults and 55% of children received at least one dose of the flu vaccine in the 2023/24 flu season, according to the US Centers for Disease Control and Prevention (CDC).
The NUDGE FLU Trials
Bhatt and his colleagues conducted three related clinical trials during the 2022/23 and 2023/24 flu seasons: NUDGE-FLU and NUDGE-FLU-2 targeted older adults, whereas NUDGE-FLU-CHRONIC targeted younger adults with chronic diseases. Nearly 2 million people were involved in the three trials.
Participants were randomized to receive one of a series of different behavioral-science-informed letters, delivered through a government-run electronic communication system, or no reminder.
People who received any of the nudges had higher rates of vaccination; among heart attack survivors, there was a 1.8% improvement and among adults without a history of heart attack, there was a 1.3% improvement. But a nudge that explained the potential cardiovascular benefits of flu shots was even more effective, leading to a 3.9% increase among people with a history of heart attack and a 2% increase among those with no heart attack history.
“A simple sentence resulted in a durable improvement in the vaccination rate,” said Bhatt.
The effect was even greater among those who had not been vaccinated in the previous flu season. Among heart attack survivors, nearly 14% more people got the vaccine compared with just 1.5% more survivors who were previously vaccinated. And it was most effective among younger adults who had experienced a recent heart attack, resulting in a 26% increase.
“The impact was larger in patients with a history of acute myocardial infarction, in those who were vaccine-hesitant, and in younger people” — all groups with the most to gain from vaccination in terms of cardiovascular protection — Bhatt reported.
About 25% of people in the United States are unsure about whether to get a flu shot, said Orly Vardeny, PharmD, professor of medicine at the University of Minnesota Medical School in Minneapolis, who was not involved in the study. The fact that previously unvaccinated people were convinced by the nudges is reassuring. “That’s the group where this intervention is most likely to move the needle,” she said.
Around half of all people hospitalized for flu in the United States have cardiovascular disease, CDC data showed, so “even a small increase in the number of patients who get vaccinated has substantial public health benefits,” Vardeny said.
The NUDGE FLU series showed that nudges like this should be employed as a simple tool to improve vaccination rates, but the system would be much more difficult to implement in the United States, Bhatt said.
Denmark has a national health service and a preexisting government electronic communication system, whereas the US system is privately run and more fractured. It would be possible to make it work, he pointed out, but would take some effort.
A version of this article first appeared on Medscape.com.
FROM AHA 2024
H5N1 Avian Influenza Spreads Across North America
It’s been a while since I’ve discussed the H5N1 avian influenza clade 2.3.4.4b and its rapid spread in North America. I hope the facts prove me wrong, but many experts have been warning for some time that ideal conditions are forming for this virus, which for now only causes zoonoses, to pose a pandemic threat.
either because they work in other medical fields or think that the experience of the COVID-19 pandemic was a worst-case scenario that is unlikely to be repeated in the short term.
The Virus Has Flown to Hawaii
According to data from the Centers for Disease Control and Prevention in Atlanta, Georgia, the infection has now affected more than 500 cattle herds in 15 states. There are about 30 outbreaks reported in poultry, equally distributed between backyard and farm-raised birds, primarily located in California. Here alone, over 3 million birds have been affected.
Wild birds are believed to have transported the highly pathogenic virus via migration routes across the Pacific, introducing it to Hawaii for the first time. Just days after wastewater analysis detected the presence of H5N1 on the island of Oahu, home to the capital Honolulu, the first outbreak was promptly reported, killing at least a dozen ducks and geese in a backyard coop. Some of these birds had been taken in early November to the Mililani Pet Fair, a sort of domestic animal festival. Local authorities recommended that anyone who attended the fair, touched a duck or goose at the event, and developed symptoms including fever, cough, sore throat, and conjunctivitis, should isolate and seek medical advice.
Meanwhile, more than 50 farmers, animal handlers, or workers involved in the slaughter of cattle or poultry across seven states have been confirmed infected, presumably contracted at their workplace. The latest case, diagnosed recently in Oregon, presented with severe conjunctivitis and mild respiratory symptoms. More than half of these patients have been identified in recent weeks in California, where active surveillance measures have been implemented. However, there is strong suspicion that the actual number of people infected with mild symptoms in the rest of the country is much, much higher.
The Red Alert Lights Up in Canada
The level of concern was raised further with news of the first severe — indeed very severe — case of H5N1 avian influenza originating from the western edge of Canada. A teenager (gender not disclosed), previously healthy and without risk factors, was hospitalized with severe respiratory failure in the intensive care unit at British Columbia Children’s Hospital in Vancouver. The source of the infection is unknown, similar to only one other case in Missouri involving an adult already hospitalized for other reasons, which was identified by chance through influenza surveillance programs. We also know that the Canadian adolescent does not live on a farm and had no known contact with potentially infected animals. The only suspicions focus on the family dog, euthanized owing to unspecified health problems in the early days of the epidemiologic investigation. Although the dog tested negative for avian influenza, a necropsy will be conducted to rule out its involvement in the transmission chain.
An initial characterization of the virus has linked it to genotype D1.1, which is circulating among wild birds and poultry farms in Canada’s westernmost province, rather than the strain typical of dairy cows in the United States. The publication of the complete viral sequence over the past weekend has, for the first time, highlighted mutations that could enhance the virus’s ability to infect human cells.
How do we know this? From the highly contested “gain-of-function” studies, which artificially modify viruses to understand which genomic points require the most surveillance — those mutations that can make the infectious agent more virulent or more transmissible between people.
Under Special Surveillance for 20 Years
The influenza A (H5N1) avian virus is not new or previously unknown, like SARS-CoV-2, and this could (in theory) give us a slight advantage. We have known about it for decades, and it began infecting humans about 20 years ago, causing pneumonia with respiratory failure. It proved lethal in about half of the cases, but only in people who had close contact with infected poultry, primarily in Southeast Asia.
Hundreds of other human cases occurred worldwide, but always in low-income countries with poor hygiene conditions and where families lived in close contact with animals. This contributed to a false sense of security in Europe and North America, where the threat has been consistently underestimated. Despite an estimated fatality rate of around 50%, the media often labeled scientists’ warnings and health authorities’ efforts to remain prepared as false alarms, tainted by suspicions of catering to the interests of pharmaceutical companies.
Some people may recall the scandal involving Tamiflu, the Roche antiviral oseltamivir, that governments stockpiled when there were fears that the avian virus might acquire the ability to spread among humans. It was dubbed “a false antidote for a false pandemic,” referring to the potential avian pandemic and the 2009 H1N1 influenza pandemic, improperly called “swine flu,” and which turned out to be less severe than expected. There was talk of €2.64 billion being “wasted” to “please” the manufacturer. Although the Cochrane Collaboration made legitimate demands for rigor and transparency in conducting and publishing clinical trials, much of the public, and the journalists who wrote the stories, cared little about these technical aspects. The prevailing message was that stockpiling drugs (or vaccines) for a disease we don’t even know will occur is a waste of taxpayers’ money rather than a prudent preventive measure.
More Vulnerable Than Ever
If we were to ascribe strategic thinking to the virus, which it is not capable of, we might argue that it chose the ideal moment to conquer the world. It began circulating in the new clade in 2020, when experts and authorities were focused on the coronavirus. It spread from birds to marine mammals and finally to cattle, exploiting the public’s post-pandemic fatigue, as people no longer wanted to hear about infectious diseases and containment measures. It ultimately rode the wave of political polarization that irrationally equates prevention with supposed cowardice on the left, and recklessness with courageous freedom on the right.
The coincidence between the future appointments announced by the incoming Trump administration and the virus’s accelerated spread deserves attention from decision-makers and health professionals worldwide. The COVID-19 pandemic experience should have taught us that ignoring a threat doesn’t make it go away, if not in our health, then at least in our wallet. The economic repercussions of a virus circulating among animals crucial to our food chain and national economies should concern everyone, well before the threat crosses the ocean, because only then can we defend ourselves.
The proposed Secretary of Health and Human Services, Robert F. Kennedy, is a proponent of the supposed benefits of raw milk, which could serve as a potent vector for the virus. He is ideologically opposed to vaccinations. It’s hard to imagine he would utilize the H5N1 vaccine stockpiles held by the US government for a campaign starting at least with farmers, as was done prophylactically in Finland with products jointly procured by 15 European countries — a group the Italian government decided not to join.
If Kennedy indeed becomes responsible for US public health, it’s reasonable to fear that, in the name of freedom, he will try to delay as much as possible — even if necessary — the obligation to undergo testing and wear masks, not to mention more restrictive infection containment measures. It’s also unlikely he would support and promote the development of new mRNA products already under study, which would become indispensable if the disease begins to spread more easily among people, as well as animals. In such a case, traditional influenza vaccine cultivation methods using chicken eggs would prove too slow and quantitatively insufficient, especially if the virus continues to circulate among poultry.
In short, let’s keep our fingers crossed, but recognize that crossing our fingers might not be enough.
This story was translated from Univadis Italy using several editorial tools, including artificial intelligence, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
It’s been a while since I’ve discussed the H5N1 avian influenza clade 2.3.4.4b and its rapid spread in North America. I hope the facts prove me wrong, but many experts have been warning for some time that ideal conditions are forming for this virus, which for now only causes zoonoses, to pose a pandemic threat.
either because they work in other medical fields or think that the experience of the COVID-19 pandemic was a worst-case scenario that is unlikely to be repeated in the short term.
The Virus Has Flown to Hawaii
According to data from the Centers for Disease Control and Prevention in Atlanta, Georgia, the infection has now affected more than 500 cattle herds in 15 states. There are about 30 outbreaks reported in poultry, equally distributed between backyard and farm-raised birds, primarily located in California. Here alone, over 3 million birds have been affected.
Wild birds are believed to have transported the highly pathogenic virus via migration routes across the Pacific, introducing it to Hawaii for the first time. Just days after wastewater analysis detected the presence of H5N1 on the island of Oahu, home to the capital Honolulu, the first outbreak was promptly reported, killing at least a dozen ducks and geese in a backyard coop. Some of these birds had been taken in early November to the Mililani Pet Fair, a sort of domestic animal festival. Local authorities recommended that anyone who attended the fair, touched a duck or goose at the event, and developed symptoms including fever, cough, sore throat, and conjunctivitis, should isolate and seek medical advice.
Meanwhile, more than 50 farmers, animal handlers, or workers involved in the slaughter of cattle or poultry across seven states have been confirmed infected, presumably contracted at their workplace. The latest case, diagnosed recently in Oregon, presented with severe conjunctivitis and mild respiratory symptoms. More than half of these patients have been identified in recent weeks in California, where active surveillance measures have been implemented. However, there is strong suspicion that the actual number of people infected with mild symptoms in the rest of the country is much, much higher.
The Red Alert Lights Up in Canada
The level of concern was raised further with news of the first severe — indeed very severe — case of H5N1 avian influenza originating from the western edge of Canada. A teenager (gender not disclosed), previously healthy and without risk factors, was hospitalized with severe respiratory failure in the intensive care unit at British Columbia Children’s Hospital in Vancouver. The source of the infection is unknown, similar to only one other case in Missouri involving an adult already hospitalized for other reasons, which was identified by chance through influenza surveillance programs. We also know that the Canadian adolescent does not live on a farm and had no known contact with potentially infected animals. The only suspicions focus on the family dog, euthanized owing to unspecified health problems in the early days of the epidemiologic investigation. Although the dog tested negative for avian influenza, a necropsy will be conducted to rule out its involvement in the transmission chain.
An initial characterization of the virus has linked it to genotype D1.1, which is circulating among wild birds and poultry farms in Canada’s westernmost province, rather than the strain typical of dairy cows in the United States. The publication of the complete viral sequence over the past weekend has, for the first time, highlighted mutations that could enhance the virus’s ability to infect human cells.
How do we know this? From the highly contested “gain-of-function” studies, which artificially modify viruses to understand which genomic points require the most surveillance — those mutations that can make the infectious agent more virulent or more transmissible between people.
Under Special Surveillance for 20 Years
The influenza A (H5N1) avian virus is not new or previously unknown, like SARS-CoV-2, and this could (in theory) give us a slight advantage. We have known about it for decades, and it began infecting humans about 20 years ago, causing pneumonia with respiratory failure. It proved lethal in about half of the cases, but only in people who had close contact with infected poultry, primarily in Southeast Asia.
Hundreds of other human cases occurred worldwide, but always in low-income countries with poor hygiene conditions and where families lived in close contact with animals. This contributed to a false sense of security in Europe and North America, where the threat has been consistently underestimated. Despite an estimated fatality rate of around 50%, the media often labeled scientists’ warnings and health authorities’ efforts to remain prepared as false alarms, tainted by suspicions of catering to the interests of pharmaceutical companies.
Some people may recall the scandal involving Tamiflu, the Roche antiviral oseltamivir, that governments stockpiled when there were fears that the avian virus might acquire the ability to spread among humans. It was dubbed “a false antidote for a false pandemic,” referring to the potential avian pandemic and the 2009 H1N1 influenza pandemic, improperly called “swine flu,” and which turned out to be less severe than expected. There was talk of €2.64 billion being “wasted” to “please” the manufacturer. Although the Cochrane Collaboration made legitimate demands for rigor and transparency in conducting and publishing clinical trials, much of the public, and the journalists who wrote the stories, cared little about these technical aspects. The prevailing message was that stockpiling drugs (or vaccines) for a disease we don’t even know will occur is a waste of taxpayers’ money rather than a prudent preventive measure.
More Vulnerable Than Ever
If we were to ascribe strategic thinking to the virus, which it is not capable of, we might argue that it chose the ideal moment to conquer the world. It began circulating in the new clade in 2020, when experts and authorities were focused on the coronavirus. It spread from birds to marine mammals and finally to cattle, exploiting the public’s post-pandemic fatigue, as people no longer wanted to hear about infectious diseases and containment measures. It ultimately rode the wave of political polarization that irrationally equates prevention with supposed cowardice on the left, and recklessness with courageous freedom on the right.
The coincidence between the future appointments announced by the incoming Trump administration and the virus’s accelerated spread deserves attention from decision-makers and health professionals worldwide. The COVID-19 pandemic experience should have taught us that ignoring a threat doesn’t make it go away, if not in our health, then at least in our wallet. The economic repercussions of a virus circulating among animals crucial to our food chain and national economies should concern everyone, well before the threat crosses the ocean, because only then can we defend ourselves.
The proposed Secretary of Health and Human Services, Robert F. Kennedy, is a proponent of the supposed benefits of raw milk, which could serve as a potent vector for the virus. He is ideologically opposed to vaccinations. It’s hard to imagine he would utilize the H5N1 vaccine stockpiles held by the US government for a campaign starting at least with farmers, as was done prophylactically in Finland with products jointly procured by 15 European countries — a group the Italian government decided not to join.
If Kennedy indeed becomes responsible for US public health, it’s reasonable to fear that, in the name of freedom, he will try to delay as much as possible — even if necessary — the obligation to undergo testing and wear masks, not to mention more restrictive infection containment measures. It’s also unlikely he would support and promote the development of new mRNA products already under study, which would become indispensable if the disease begins to spread more easily among people, as well as animals. In such a case, traditional influenza vaccine cultivation methods using chicken eggs would prove too slow and quantitatively insufficient, especially if the virus continues to circulate among poultry.
In short, let’s keep our fingers crossed, but recognize that crossing our fingers might not be enough.
This story was translated from Univadis Italy using several editorial tools, including artificial intelligence, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
It’s been a while since I’ve discussed the H5N1 avian influenza clade 2.3.4.4b and its rapid spread in North America. I hope the facts prove me wrong, but many experts have been warning for some time that ideal conditions are forming for this virus, which for now only causes zoonoses, to pose a pandemic threat.
either because they work in other medical fields or think that the experience of the COVID-19 pandemic was a worst-case scenario that is unlikely to be repeated in the short term.
The Virus Has Flown to Hawaii
According to data from the Centers for Disease Control and Prevention in Atlanta, Georgia, the infection has now affected more than 500 cattle herds in 15 states. There are about 30 outbreaks reported in poultry, equally distributed between backyard and farm-raised birds, primarily located in California. Here alone, over 3 million birds have been affected.
Wild birds are believed to have transported the highly pathogenic virus via migration routes across the Pacific, introducing it to Hawaii for the first time. Just days after wastewater analysis detected the presence of H5N1 on the island of Oahu, home to the capital Honolulu, the first outbreak was promptly reported, killing at least a dozen ducks and geese in a backyard coop. Some of these birds had been taken in early November to the Mililani Pet Fair, a sort of domestic animal festival. Local authorities recommended that anyone who attended the fair, touched a duck or goose at the event, and developed symptoms including fever, cough, sore throat, and conjunctivitis, should isolate and seek medical advice.
Meanwhile, more than 50 farmers, animal handlers, or workers involved in the slaughter of cattle or poultry across seven states have been confirmed infected, presumably contracted at their workplace. The latest case, diagnosed recently in Oregon, presented with severe conjunctivitis and mild respiratory symptoms. More than half of these patients have been identified in recent weeks in California, where active surveillance measures have been implemented. However, there is strong suspicion that the actual number of people infected with mild symptoms in the rest of the country is much, much higher.
The Red Alert Lights Up in Canada
The level of concern was raised further with news of the first severe — indeed very severe — case of H5N1 avian influenza originating from the western edge of Canada. A teenager (gender not disclosed), previously healthy and without risk factors, was hospitalized with severe respiratory failure in the intensive care unit at British Columbia Children’s Hospital in Vancouver. The source of the infection is unknown, similar to only one other case in Missouri involving an adult already hospitalized for other reasons, which was identified by chance through influenza surveillance programs. We also know that the Canadian adolescent does not live on a farm and had no known contact with potentially infected animals. The only suspicions focus on the family dog, euthanized owing to unspecified health problems in the early days of the epidemiologic investigation. Although the dog tested negative for avian influenza, a necropsy will be conducted to rule out its involvement in the transmission chain.
An initial characterization of the virus has linked it to genotype D1.1, which is circulating among wild birds and poultry farms in Canada’s westernmost province, rather than the strain typical of dairy cows in the United States. The publication of the complete viral sequence over the past weekend has, for the first time, highlighted mutations that could enhance the virus’s ability to infect human cells.
How do we know this? From the highly contested “gain-of-function” studies, which artificially modify viruses to understand which genomic points require the most surveillance — those mutations that can make the infectious agent more virulent or more transmissible between people.
Under Special Surveillance for 20 Years
The influenza A (H5N1) avian virus is not new or previously unknown, like SARS-CoV-2, and this could (in theory) give us a slight advantage. We have known about it for decades, and it began infecting humans about 20 years ago, causing pneumonia with respiratory failure. It proved lethal in about half of the cases, but only in people who had close contact with infected poultry, primarily in Southeast Asia.
Hundreds of other human cases occurred worldwide, but always in low-income countries with poor hygiene conditions and where families lived in close contact with animals. This contributed to a false sense of security in Europe and North America, where the threat has been consistently underestimated. Despite an estimated fatality rate of around 50%, the media often labeled scientists’ warnings and health authorities’ efforts to remain prepared as false alarms, tainted by suspicions of catering to the interests of pharmaceutical companies.
Some people may recall the scandal involving Tamiflu, the Roche antiviral oseltamivir, that governments stockpiled when there were fears that the avian virus might acquire the ability to spread among humans. It was dubbed “a false antidote for a false pandemic,” referring to the potential avian pandemic and the 2009 H1N1 influenza pandemic, improperly called “swine flu,” and which turned out to be less severe than expected. There was talk of €2.64 billion being “wasted” to “please” the manufacturer. Although the Cochrane Collaboration made legitimate demands for rigor and transparency in conducting and publishing clinical trials, much of the public, and the journalists who wrote the stories, cared little about these technical aspects. The prevailing message was that stockpiling drugs (or vaccines) for a disease we don’t even know will occur is a waste of taxpayers’ money rather than a prudent preventive measure.
More Vulnerable Than Ever
If we were to ascribe strategic thinking to the virus, which it is not capable of, we might argue that it chose the ideal moment to conquer the world. It began circulating in the new clade in 2020, when experts and authorities were focused on the coronavirus. It spread from birds to marine mammals and finally to cattle, exploiting the public’s post-pandemic fatigue, as people no longer wanted to hear about infectious diseases and containment measures. It ultimately rode the wave of political polarization that irrationally equates prevention with supposed cowardice on the left, and recklessness with courageous freedom on the right.
The coincidence between the future appointments announced by the incoming Trump administration and the virus’s accelerated spread deserves attention from decision-makers and health professionals worldwide. The COVID-19 pandemic experience should have taught us that ignoring a threat doesn’t make it go away, if not in our health, then at least in our wallet. The economic repercussions of a virus circulating among animals crucial to our food chain and national economies should concern everyone, well before the threat crosses the ocean, because only then can we defend ourselves.
The proposed Secretary of Health and Human Services, Robert F. Kennedy, is a proponent of the supposed benefits of raw milk, which could serve as a potent vector for the virus. He is ideologically opposed to vaccinations. It’s hard to imagine he would utilize the H5N1 vaccine stockpiles held by the US government for a campaign starting at least with farmers, as was done prophylactically in Finland with products jointly procured by 15 European countries — a group the Italian government decided not to join.
If Kennedy indeed becomes responsible for US public health, it’s reasonable to fear that, in the name of freedom, he will try to delay as much as possible — even if necessary — the obligation to undergo testing and wear masks, not to mention more restrictive infection containment measures. It’s also unlikely he would support and promote the development of new mRNA products already under study, which would become indispensable if the disease begins to spread more easily among people, as well as animals. In such a case, traditional influenza vaccine cultivation methods using chicken eggs would prove too slow and quantitatively insufficient, especially if the virus continues to circulate among poultry.
In short, let’s keep our fingers crossed, but recognize that crossing our fingers might not be enough.
This story was translated from Univadis Italy using several editorial tools, including artificial intelligence, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
Flu Vaccine Guards Household Contacts of Infected People
TOPLINE:
Vaccination lowers the risk of contracting the infection among household contacts.
METHODOLOGY:
- Researchers conducted a prospective cohort study of data between 2017 and 2020 to determine the estimated effectiveness of influenza vaccines in preventing secondary infections in household contacts.
- Overall, 699 people were primary contacts, or the first in a household to get infected (median age, 13 years; 54.5% women); there were 1581 household contacts (median age, 31 years; 52.7% women), and both groups were followed for 7 days.
- Participants collected daily symptom diaries and nasal swabs during the follow-up period.
- Participants also submitted their history of influenza vaccination; 50.1% of household contacts had received a shot at least 14 days before the first case of disease onset in the household.
- The risk for secondary infection and vaccine effectiveness in preventing infection among household contacts was estimated overall and by virus type, subtype, and lineage.
TAKEAWAY:
- Nearly half (48.2%) of primary cases were from children and teens between ages 5 and 17 years.
- Overall, 22% household contacts had laboratory-confirmed influenza during follow-up, of which 7% were asymptomatic.
- The overall risk for secondary infection among unvaccinated household contacts was 18.8%, with the highest risk observed among children younger than age 5 years (29.9%).
- The overall effectiveness of influenza vaccines in preventing laboratory-confirmed infections among household contacts was 21% (95% CI, 1.4%-36.7%).
- The vaccine demonstrated specific protection against influenza B infection (56.4%; 95% CI, 30.1%-72.8%), particularly among those between ages 5 and 17 years.
IN PRACTICE:
“Although complementary preventive strategies to prevent influenza in household settings may be considered, seasonal influenza vaccination is the primary strategy recommended for prevention of influenza illness and its complications,” the authors wrote.
SOURCE:
The study was led by Carlos G. Grijalva, MD, MPH, of Vanderbilt University Medical Center in Nashville, Tennessee, and was published online in JAMA Network Open.
LIMITATIONS:
The recruitment of infected individuals from clinical testing pools may have limited the generalizability of the risk for secondary infection in households in which the primary case had a milder or asymptomatic infection. The study was unable to assess the effectiveness of specific vaccine formulations, such as those receiving high doses. The stratification of estimates by influenza subtypes and lineages was challenging because of small cell sizes.
DISCLOSURES:
This study was supported by grants from the Centers for Disease Control and Prevention (CDC) and authors reported support from grants from the National Institute Of Allergy And Infectious Diseases. Some authors reported contracts, receiving personal fees and grants from the CDC and various pharmaceutical companies such as Merck and Sanofi.
This article was created using several editorial tools, including artificial intelligence, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
Vaccination lowers the risk of contracting the infection among household contacts.
METHODOLOGY:
- Researchers conducted a prospective cohort study of data between 2017 and 2020 to determine the estimated effectiveness of influenza vaccines in preventing secondary infections in household contacts.
- Overall, 699 people were primary contacts, or the first in a household to get infected (median age, 13 years; 54.5% women); there were 1581 household contacts (median age, 31 years; 52.7% women), and both groups were followed for 7 days.
- Participants collected daily symptom diaries and nasal swabs during the follow-up period.
- Participants also submitted their history of influenza vaccination; 50.1% of household contacts had received a shot at least 14 days before the first case of disease onset in the household.
- The risk for secondary infection and vaccine effectiveness in preventing infection among household contacts was estimated overall and by virus type, subtype, and lineage.
TAKEAWAY:
- Nearly half (48.2%) of primary cases were from children and teens between ages 5 and 17 years.
- Overall, 22% household contacts had laboratory-confirmed influenza during follow-up, of which 7% were asymptomatic.
- The overall risk for secondary infection among unvaccinated household contacts was 18.8%, with the highest risk observed among children younger than age 5 years (29.9%).
- The overall effectiveness of influenza vaccines in preventing laboratory-confirmed infections among household contacts was 21% (95% CI, 1.4%-36.7%).
- The vaccine demonstrated specific protection against influenza B infection (56.4%; 95% CI, 30.1%-72.8%), particularly among those between ages 5 and 17 years.
IN PRACTICE:
“Although complementary preventive strategies to prevent influenza in household settings may be considered, seasonal influenza vaccination is the primary strategy recommended for prevention of influenza illness and its complications,” the authors wrote.
SOURCE:
The study was led by Carlos G. Grijalva, MD, MPH, of Vanderbilt University Medical Center in Nashville, Tennessee, and was published online in JAMA Network Open.
LIMITATIONS:
The recruitment of infected individuals from clinical testing pools may have limited the generalizability of the risk for secondary infection in households in which the primary case had a milder or asymptomatic infection. The study was unable to assess the effectiveness of specific vaccine formulations, such as those receiving high doses. The stratification of estimates by influenza subtypes and lineages was challenging because of small cell sizes.
DISCLOSURES:
This study was supported by grants from the Centers for Disease Control and Prevention (CDC) and authors reported support from grants from the National Institute Of Allergy And Infectious Diseases. Some authors reported contracts, receiving personal fees and grants from the CDC and various pharmaceutical companies such as Merck and Sanofi.
This article was created using several editorial tools, including artificial intelligence, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
Vaccination lowers the risk of contracting the infection among household contacts.
METHODOLOGY:
- Researchers conducted a prospective cohort study of data between 2017 and 2020 to determine the estimated effectiveness of influenza vaccines in preventing secondary infections in household contacts.
- Overall, 699 people were primary contacts, or the first in a household to get infected (median age, 13 years; 54.5% women); there were 1581 household contacts (median age, 31 years; 52.7% women), and both groups were followed for 7 days.
- Participants collected daily symptom diaries and nasal swabs during the follow-up period.
- Participants also submitted their history of influenza vaccination; 50.1% of household contacts had received a shot at least 14 days before the first case of disease onset in the household.
- The risk for secondary infection and vaccine effectiveness in preventing infection among household contacts was estimated overall and by virus type, subtype, and lineage.
TAKEAWAY:
- Nearly half (48.2%) of primary cases were from children and teens between ages 5 and 17 years.
- Overall, 22% household contacts had laboratory-confirmed influenza during follow-up, of which 7% were asymptomatic.
- The overall risk for secondary infection among unvaccinated household contacts was 18.8%, with the highest risk observed among children younger than age 5 years (29.9%).
- The overall effectiveness of influenza vaccines in preventing laboratory-confirmed infections among household contacts was 21% (95% CI, 1.4%-36.7%).
- The vaccine demonstrated specific protection against influenza B infection (56.4%; 95% CI, 30.1%-72.8%), particularly among those between ages 5 and 17 years.
IN PRACTICE:
“Although complementary preventive strategies to prevent influenza in household settings may be considered, seasonal influenza vaccination is the primary strategy recommended for prevention of influenza illness and its complications,” the authors wrote.
SOURCE:
The study was led by Carlos G. Grijalva, MD, MPH, of Vanderbilt University Medical Center in Nashville, Tennessee, and was published online in JAMA Network Open.
LIMITATIONS:
The recruitment of infected individuals from clinical testing pools may have limited the generalizability of the risk for secondary infection in households in which the primary case had a milder or asymptomatic infection. The study was unable to assess the effectiveness of specific vaccine formulations, such as those receiving high doses. The stratification of estimates by influenza subtypes and lineages was challenging because of small cell sizes.
DISCLOSURES:
This study was supported by grants from the Centers for Disease Control and Prevention (CDC) and authors reported support from grants from the National Institute Of Allergy And Infectious Diseases. Some authors reported contracts, receiving personal fees and grants from the CDC and various pharmaceutical companies such as Merck and Sanofi.
This article was created using several editorial tools, including artificial intelligence, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
It’s Not Too Late for Influenza Vaccination: Q&A With CDC’s Dr. Lisa Grohskopf
Text has been edited for length.
Are there any updates to this season’s influenza vaccine or vaccine recommendations?
Yes, we have updates to both the vaccine and the vaccine recommendations this year. Typically we have some changes each year, and this year there are two main changes in the recommendations. One relates to the composition of the vaccine for this season, and the other is a new recommendation for adult solid organ transplant recipients.
We typically have changes in the vaccine composition each season. For most seasons, one or more parts of the vaccine will change, but this year is a little different in that all of the vaccines available in the US for the 2024-2025 season are going to be three-virus, or trivalent, vaccines. They are going to be formulated to protect against three viruses: an influenza A(H1N1) virus, an influenza A(H3N2) virus, and an influenza B/Victoria lineage virus.
The reason for this change is that since the 2013-2014 season through the 2023-2024 season, we had quadrivalent vaccines that were available in the US that contained four viruses. Those vaccines contained a second influenza B virus from the Yamagata lineage (B viruses come from two main lineages).
The reason for the change to trivalent vaccines this season is that influenza B/Yamagata viruses have not been detected in global surveillance since March 2020, and so their inclusion is no longer warranted. So this season, all of the vaccines available in the US are going to be trivalent.
In addition to that change, we have an update in the influenza A(H3N2) component of the vaccine compared with last season.
The second change concerning adult solid organ transplant recipients is that Advisory Committee on Immunization Practices (ACIP) now recommends that solid organ transplant recipients aged 18-64 years can receive as acceptable options either the high-dose inactivated vaccine or the adjuvanted inactivated vaccine without a preference over other age appropriate, inactivated, or recombinant vaccines.
Those vaccines are both formulated with features intended to make them more immunogenic — ie, promote a stronger immune response — and there are data for immunogenicity that suggest they could be more immunogenic in that population.
Who needs an influenza vaccine this season?
That recommendation is the same as it’s been for a number of years, which is that everybody aged 6 months or older is recommended to get a flu vaccine, with some rare exceptions, mainly concerning contraindications to vaccination.
Contraindications are detailed in the ACIP flu statement each year, and they’re relatively uncommon conditions overall, so most people are recommended, if they’re in that age group 6 months and up, to get an annual flu vaccine.
Are there groups for whom influenza vaccination is especially important?
Yes. While influenza vaccination is recommended for everybody in that age group 6 months and up — and in truth, we can never really predict who’s going to get severely ill — some people are more likely to be at risk of having serious illness or hospitalization. Those people include adults aged 65 years or older; young children; people with certain chronic health conditions such as heart disease, lung disease, and diabetes; and people from some racial and ethnic groups.
Are there any specific influenza vaccination recommendations for these groups or others?
Not for most people. In general, we have a number of different influenza vaccines each season; this year we have a total of nine brands. In general, there’s no preferential recommendation for one vaccine or type of vaccine for specific groups of people, with one exception: For people aged 65 years or older, there’s a preferential recommendation for three specific vaccines — the high-dose inactivated vaccine, Fluzone High-Dose; the recombinant vaccine, Flublok; and the adjuvanted inactivated vaccine, FLUAD.
Among those three, there’s no preference for any one of them over the other two; they’re all preferred vaccines for this age group, if available. If none of those three vaccines are available at the time that somebody aged 65 or older is there to get vaccinated, people in this age group should get any other age-appropriate influenza vaccine that is available.
When should people get vaccinated if they haven’t already?
CDC and ACIP recommend vaccination for most people, ideally by the end of October. But for those who missed the end of October, it is absolutely not too late. Providers should continue to encourage vaccination and people should get their vaccines as long as flu viruses are circulating.
The timing of the onset and the peak and the end of the flu season vary a bit from year to year. We often start to see generally activity begin to increase in the US in the fall, which is the reason for the end of October recommendation; however, flu activity doesn’t tend to peak in the US until after October. We’re talking December, January, or later, so getting vaccinated after October can still provide important protection during the peak of the season.
There does seem to be a tendency for people to think, OK, I haven’t gotten the vaccine yet, and there probably isn’t a lot of reason to do it now. But really, it’s definitely not too late, and that’s something we like to encourage people to think about, particularly as we move into December and January — it’s not too late if you missed October.
Influenza vaccination is also available in so many places. You don’t necessarily have to go to a healthcare provider’s office; there are many retail chains which offer influenza vaccines.
Is influenza spreading right now? Are activity levels increasing?
Overall influenza activity currently is low nationally, although there’s starting to be some slight increases in the pediatric age groups and, of course, we do anticipate that it will increase in the coming weeks and months.
When we get vaccinated, the protection isn’t instantaneous. The immune system needs a bit of time to react to the vaccine and to develop antibodies. That can take about 2 weeks. Even with that, now is still absolutely not too late to get a vaccine. Neither is December, for that matter. As long as the flu viruses are circulating where you are, it is still worth getting vaccinated.
What was influenza vaccination coverage like last season?
It’s a little bit early to tell for the current season, but one of the things that we do know is that since the COVID-19 pandemic, coverage has dropped compared with before the COVID-19 pandemic. Before COVID-19, influenza vaccination coverage had been slowly increasing in most groups, but it has decreased since then, and those downturns in coverage haven’t recovered to prepandemic levels. For example, during 2023-2024, about half of children and adults received a flu vaccine.
What can providers do to encourage influenza vaccination in their patients?
We know that a healthcare provider’s strong recommendation for flu vaccination is a really major factor in whether or not patients get a flu vaccine, and is more effective in increasing acceptance of vaccination than just about any other factor.
There’s a method from CDC called SHARE, which is a helpful way to help make a strong recommendation and provide information to help patients make an informed decision about whether or not they want to be vaccinated.
To implement SHARE, it’s an acronym with five parts. S is for Share the reasons why the flu vaccine is right for that patient. H is for Highlight positive experiences with flu vaccination, either personal or in practice. A is for Address patient concerns and questions about the flu vaccine, including things such as side effects, safety, and effectiveness. R is Remind patients that vaccination protects them and their loved ones from serious illness and related complications. E is Explain the potential complications and consequences of getting influenza, including serious health effects, time lost from family, work, and school, and potential financial costs.
Additional resources are accessible on CDC’s influenza resources page, including brochures, posters, and fact sheets that can help providers in encouraging and reminding people to get vaccinated.
A version of this article appeared on Medscape.com.
Text has been edited for length.
Are there any updates to this season’s influenza vaccine or vaccine recommendations?
Yes, we have updates to both the vaccine and the vaccine recommendations this year. Typically we have some changes each year, and this year there are two main changes in the recommendations. One relates to the composition of the vaccine for this season, and the other is a new recommendation for adult solid organ transplant recipients.
We typically have changes in the vaccine composition each season. For most seasons, one or more parts of the vaccine will change, but this year is a little different in that all of the vaccines available in the US for the 2024-2025 season are going to be three-virus, or trivalent, vaccines. They are going to be formulated to protect against three viruses: an influenza A(H1N1) virus, an influenza A(H3N2) virus, and an influenza B/Victoria lineage virus.
The reason for this change is that since the 2013-2014 season through the 2023-2024 season, we had quadrivalent vaccines that were available in the US that contained four viruses. Those vaccines contained a second influenza B virus from the Yamagata lineage (B viruses come from two main lineages).
The reason for the change to trivalent vaccines this season is that influenza B/Yamagata viruses have not been detected in global surveillance since March 2020, and so their inclusion is no longer warranted. So this season, all of the vaccines available in the US are going to be trivalent.
In addition to that change, we have an update in the influenza A(H3N2) component of the vaccine compared with last season.
The second change concerning adult solid organ transplant recipients is that Advisory Committee on Immunization Practices (ACIP) now recommends that solid organ transplant recipients aged 18-64 years can receive as acceptable options either the high-dose inactivated vaccine or the adjuvanted inactivated vaccine without a preference over other age appropriate, inactivated, or recombinant vaccines.
Those vaccines are both formulated with features intended to make them more immunogenic — ie, promote a stronger immune response — and there are data for immunogenicity that suggest they could be more immunogenic in that population.
Who needs an influenza vaccine this season?
That recommendation is the same as it’s been for a number of years, which is that everybody aged 6 months or older is recommended to get a flu vaccine, with some rare exceptions, mainly concerning contraindications to vaccination.
Contraindications are detailed in the ACIP flu statement each year, and they’re relatively uncommon conditions overall, so most people are recommended, if they’re in that age group 6 months and up, to get an annual flu vaccine.
Are there groups for whom influenza vaccination is especially important?
Yes. While influenza vaccination is recommended for everybody in that age group 6 months and up — and in truth, we can never really predict who’s going to get severely ill — some people are more likely to be at risk of having serious illness or hospitalization. Those people include adults aged 65 years or older; young children; people with certain chronic health conditions such as heart disease, lung disease, and diabetes; and people from some racial and ethnic groups.
Are there any specific influenza vaccination recommendations for these groups or others?
Not for most people. In general, we have a number of different influenza vaccines each season; this year we have a total of nine brands. In general, there’s no preferential recommendation for one vaccine or type of vaccine for specific groups of people, with one exception: For people aged 65 years or older, there’s a preferential recommendation for three specific vaccines — the high-dose inactivated vaccine, Fluzone High-Dose; the recombinant vaccine, Flublok; and the adjuvanted inactivated vaccine, FLUAD.
Among those three, there’s no preference for any one of them over the other two; they’re all preferred vaccines for this age group, if available. If none of those three vaccines are available at the time that somebody aged 65 or older is there to get vaccinated, people in this age group should get any other age-appropriate influenza vaccine that is available.
When should people get vaccinated if they haven’t already?
CDC and ACIP recommend vaccination for most people, ideally by the end of October. But for those who missed the end of October, it is absolutely not too late. Providers should continue to encourage vaccination and people should get their vaccines as long as flu viruses are circulating.
The timing of the onset and the peak and the end of the flu season vary a bit from year to year. We often start to see generally activity begin to increase in the US in the fall, which is the reason for the end of October recommendation; however, flu activity doesn’t tend to peak in the US until after October. We’re talking December, January, or later, so getting vaccinated after October can still provide important protection during the peak of the season.
There does seem to be a tendency for people to think, OK, I haven’t gotten the vaccine yet, and there probably isn’t a lot of reason to do it now. But really, it’s definitely not too late, and that’s something we like to encourage people to think about, particularly as we move into December and January — it’s not too late if you missed October.
Influenza vaccination is also available in so many places. You don’t necessarily have to go to a healthcare provider’s office; there are many retail chains which offer influenza vaccines.
Is influenza spreading right now? Are activity levels increasing?
Overall influenza activity currently is low nationally, although there’s starting to be some slight increases in the pediatric age groups and, of course, we do anticipate that it will increase in the coming weeks and months.
When we get vaccinated, the protection isn’t instantaneous. The immune system needs a bit of time to react to the vaccine and to develop antibodies. That can take about 2 weeks. Even with that, now is still absolutely not too late to get a vaccine. Neither is December, for that matter. As long as the flu viruses are circulating where you are, it is still worth getting vaccinated.
What was influenza vaccination coverage like last season?
It’s a little bit early to tell for the current season, but one of the things that we do know is that since the COVID-19 pandemic, coverage has dropped compared with before the COVID-19 pandemic. Before COVID-19, influenza vaccination coverage had been slowly increasing in most groups, but it has decreased since then, and those downturns in coverage haven’t recovered to prepandemic levels. For example, during 2023-2024, about half of children and adults received a flu vaccine.
What can providers do to encourage influenza vaccination in their patients?
We know that a healthcare provider’s strong recommendation for flu vaccination is a really major factor in whether or not patients get a flu vaccine, and is more effective in increasing acceptance of vaccination than just about any other factor.
There’s a method from CDC called SHARE, which is a helpful way to help make a strong recommendation and provide information to help patients make an informed decision about whether or not they want to be vaccinated.
To implement SHARE, it’s an acronym with five parts. S is for Share the reasons why the flu vaccine is right for that patient. H is for Highlight positive experiences with flu vaccination, either personal or in practice. A is for Address patient concerns and questions about the flu vaccine, including things such as side effects, safety, and effectiveness. R is Remind patients that vaccination protects them and their loved ones from serious illness and related complications. E is Explain the potential complications and consequences of getting influenza, including serious health effects, time lost from family, work, and school, and potential financial costs.
Additional resources are accessible on CDC’s influenza resources page, including brochures, posters, and fact sheets that can help providers in encouraging and reminding people to get vaccinated.
A version of this article appeared on Medscape.com.
Text has been edited for length.
Are there any updates to this season’s influenza vaccine or vaccine recommendations?
Yes, we have updates to both the vaccine and the vaccine recommendations this year. Typically we have some changes each year, and this year there are two main changes in the recommendations. One relates to the composition of the vaccine for this season, and the other is a new recommendation for adult solid organ transplant recipients.
We typically have changes in the vaccine composition each season. For most seasons, one or more parts of the vaccine will change, but this year is a little different in that all of the vaccines available in the US for the 2024-2025 season are going to be three-virus, or trivalent, vaccines. They are going to be formulated to protect against three viruses: an influenza A(H1N1) virus, an influenza A(H3N2) virus, and an influenza B/Victoria lineage virus.
The reason for this change is that since the 2013-2014 season through the 2023-2024 season, we had quadrivalent vaccines that were available in the US that contained four viruses. Those vaccines contained a second influenza B virus from the Yamagata lineage (B viruses come from two main lineages).
The reason for the change to trivalent vaccines this season is that influenza B/Yamagata viruses have not been detected in global surveillance since March 2020, and so their inclusion is no longer warranted. So this season, all of the vaccines available in the US are going to be trivalent.
In addition to that change, we have an update in the influenza A(H3N2) component of the vaccine compared with last season.
The second change concerning adult solid organ transplant recipients is that Advisory Committee on Immunization Practices (ACIP) now recommends that solid organ transplant recipients aged 18-64 years can receive as acceptable options either the high-dose inactivated vaccine or the adjuvanted inactivated vaccine without a preference over other age appropriate, inactivated, or recombinant vaccines.
Those vaccines are both formulated with features intended to make them more immunogenic — ie, promote a stronger immune response — and there are data for immunogenicity that suggest they could be more immunogenic in that population.
Who needs an influenza vaccine this season?
That recommendation is the same as it’s been for a number of years, which is that everybody aged 6 months or older is recommended to get a flu vaccine, with some rare exceptions, mainly concerning contraindications to vaccination.
Contraindications are detailed in the ACIP flu statement each year, and they’re relatively uncommon conditions overall, so most people are recommended, if they’re in that age group 6 months and up, to get an annual flu vaccine.
Are there groups for whom influenza vaccination is especially important?
Yes. While influenza vaccination is recommended for everybody in that age group 6 months and up — and in truth, we can never really predict who’s going to get severely ill — some people are more likely to be at risk of having serious illness or hospitalization. Those people include adults aged 65 years or older; young children; people with certain chronic health conditions such as heart disease, lung disease, and diabetes; and people from some racial and ethnic groups.
Are there any specific influenza vaccination recommendations for these groups or others?
Not for most people. In general, we have a number of different influenza vaccines each season; this year we have a total of nine brands. In general, there’s no preferential recommendation for one vaccine or type of vaccine for specific groups of people, with one exception: For people aged 65 years or older, there’s a preferential recommendation for three specific vaccines — the high-dose inactivated vaccine, Fluzone High-Dose; the recombinant vaccine, Flublok; and the adjuvanted inactivated vaccine, FLUAD.
Among those three, there’s no preference for any one of them over the other two; they’re all preferred vaccines for this age group, if available. If none of those three vaccines are available at the time that somebody aged 65 or older is there to get vaccinated, people in this age group should get any other age-appropriate influenza vaccine that is available.
When should people get vaccinated if they haven’t already?
CDC and ACIP recommend vaccination for most people, ideally by the end of October. But for those who missed the end of October, it is absolutely not too late. Providers should continue to encourage vaccination and people should get their vaccines as long as flu viruses are circulating.
The timing of the onset and the peak and the end of the flu season vary a bit from year to year. We often start to see generally activity begin to increase in the US in the fall, which is the reason for the end of October recommendation; however, flu activity doesn’t tend to peak in the US until after October. We’re talking December, January, or later, so getting vaccinated after October can still provide important protection during the peak of the season.
There does seem to be a tendency for people to think, OK, I haven’t gotten the vaccine yet, and there probably isn’t a lot of reason to do it now. But really, it’s definitely not too late, and that’s something we like to encourage people to think about, particularly as we move into December and January — it’s not too late if you missed October.
Influenza vaccination is also available in so many places. You don’t necessarily have to go to a healthcare provider’s office; there are many retail chains which offer influenza vaccines.
Is influenza spreading right now? Are activity levels increasing?
Overall influenza activity currently is low nationally, although there’s starting to be some slight increases in the pediatric age groups and, of course, we do anticipate that it will increase in the coming weeks and months.
When we get vaccinated, the protection isn’t instantaneous. The immune system needs a bit of time to react to the vaccine and to develop antibodies. That can take about 2 weeks. Even with that, now is still absolutely not too late to get a vaccine. Neither is December, for that matter. As long as the flu viruses are circulating where you are, it is still worth getting vaccinated.
What was influenza vaccination coverage like last season?
It’s a little bit early to tell for the current season, but one of the things that we do know is that since the COVID-19 pandemic, coverage has dropped compared with before the COVID-19 pandemic. Before COVID-19, influenza vaccination coverage had been slowly increasing in most groups, but it has decreased since then, and those downturns in coverage haven’t recovered to prepandemic levels. For example, during 2023-2024, about half of children and adults received a flu vaccine.
What can providers do to encourage influenza vaccination in their patients?
We know that a healthcare provider’s strong recommendation for flu vaccination is a really major factor in whether or not patients get a flu vaccine, and is more effective in increasing acceptance of vaccination than just about any other factor.
There’s a method from CDC called SHARE, which is a helpful way to help make a strong recommendation and provide information to help patients make an informed decision about whether or not they want to be vaccinated.
To implement SHARE, it’s an acronym with five parts. S is for Share the reasons why the flu vaccine is right for that patient. H is for Highlight positive experiences with flu vaccination, either personal or in practice. A is for Address patient concerns and questions about the flu vaccine, including things such as side effects, safety, and effectiveness. R is Remind patients that vaccination protects them and their loved ones from serious illness and related complications. E is Explain the potential complications and consequences of getting influenza, including serious health effects, time lost from family, work, and school, and potential financial costs.
Additional resources are accessible on CDC’s influenza resources page, including brochures, posters, and fact sheets that can help providers in encouraging and reminding people to get vaccinated.
A version of this article appeared on Medscape.com.
Does Antibiotic Use During Influenza Infection Worsen Lung Immunity?
TOPLINE:
Antibiotic use during influenza infection increases lung eosinophils, impairing immunity against secondary bacterial pneumonia. This study highlights the detrimental effects of antibiotics on lung health during viral infections.
METHODOLOGY:
- Researchers conducted a murine model study to evaluate the impact of antibiotic use during influenza infection on lung immunity. Mice were treated with a broad-spectrum antibiotic cocktail (vancomycin, neomycin, ampicillin, and metronidazole) starting 7 days before influenza infection.
- The study included intranasal infection with influenza virus followed by a secondary challenge with methicillin-resistant Staphylococcus aureus (MRSA).
- Finally, in sub-study, a total of three cohorts of hospitalized patients were evaluated to correlate eosinophil levels with antibiotic use, systemic inflammation, and outcomes.
TAKEAWAY:
- Antibiotic use during influenza infection impairs lung immunity, leading to increased lung eosinophils and reduced macrophage function.
- The study found that antibiotic treatment during influenza infection caused fungal dysbiosis, driving lung eosinophilia and impairing MRSA clearance.
- The detrimental effects of antibiotics on lung immunity were specific to the two-hit model of influenza followed by MRSA infection in mice.
- In hospitalized patients, eosinophil levels positively correlated with antibiotic use, systemic inflammation, and worsened outcomes.
IN PRACTICE:
“Our study highlights the pernicious effects of antibiotic use during viral infections and defines a mechanism whereby antibiotics perturb the gut mycobiome and result in lung eosinophilia. In turn, lung eosinophils, via release of MBP-1, suppress alveolar macrophage clearance of bacteria,” the authors of the study wrote.
SOURCE:
This study was led by Marilia Sanches Santos Rizzo Zuttion, Cedars-Sinai Medical Center in Los Angeles. It was published online in The Journal of Clinical Investigation.
LIMITATIONS:
This study’s limitations included the use of a murine model, which may not fully replicate human immune responses. Additionally, the study focused on a specific antibiotic cocktail, and results may vary with different antibiotics. The findings were also specific to the two-hit model of influenza followed by MRSA infection, limiting generalizability to other infections.
DISCLOSURES:
This study was supported by grants from the National Institutes of Health. Marilia Sanches Santos Rizzo Zuttion received research funding from Pfizer Inc. Additional disclosures are noted in the original article.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
TOPLINE:
Antibiotic use during influenza infection increases lung eosinophils, impairing immunity against secondary bacterial pneumonia. This study highlights the detrimental effects of antibiotics on lung health during viral infections.
METHODOLOGY:
- Researchers conducted a murine model study to evaluate the impact of antibiotic use during influenza infection on lung immunity. Mice were treated with a broad-spectrum antibiotic cocktail (vancomycin, neomycin, ampicillin, and metronidazole) starting 7 days before influenza infection.
- The study included intranasal infection with influenza virus followed by a secondary challenge with methicillin-resistant Staphylococcus aureus (MRSA).
- Finally, in sub-study, a total of three cohorts of hospitalized patients were evaluated to correlate eosinophil levels with antibiotic use, systemic inflammation, and outcomes.
TAKEAWAY:
- Antibiotic use during influenza infection impairs lung immunity, leading to increased lung eosinophils and reduced macrophage function.
- The study found that antibiotic treatment during influenza infection caused fungal dysbiosis, driving lung eosinophilia and impairing MRSA clearance.
- The detrimental effects of antibiotics on lung immunity were specific to the two-hit model of influenza followed by MRSA infection in mice.
- In hospitalized patients, eosinophil levels positively correlated with antibiotic use, systemic inflammation, and worsened outcomes.
IN PRACTICE:
“Our study highlights the pernicious effects of antibiotic use during viral infections and defines a mechanism whereby antibiotics perturb the gut mycobiome and result in lung eosinophilia. In turn, lung eosinophils, via release of MBP-1, suppress alveolar macrophage clearance of bacteria,” the authors of the study wrote.
SOURCE:
This study was led by Marilia Sanches Santos Rizzo Zuttion, Cedars-Sinai Medical Center in Los Angeles. It was published online in The Journal of Clinical Investigation.
LIMITATIONS:
This study’s limitations included the use of a murine model, which may not fully replicate human immune responses. Additionally, the study focused on a specific antibiotic cocktail, and results may vary with different antibiotics. The findings were also specific to the two-hit model of influenza followed by MRSA infection, limiting generalizability to other infections.
DISCLOSURES:
This study was supported by grants from the National Institutes of Health. Marilia Sanches Santos Rizzo Zuttion received research funding from Pfizer Inc. Additional disclosures are noted in the original article.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
TOPLINE:
Antibiotic use during influenza infection increases lung eosinophils, impairing immunity against secondary bacterial pneumonia. This study highlights the detrimental effects of antibiotics on lung health during viral infections.
METHODOLOGY:
- Researchers conducted a murine model study to evaluate the impact of antibiotic use during influenza infection on lung immunity. Mice were treated with a broad-spectrum antibiotic cocktail (vancomycin, neomycin, ampicillin, and metronidazole) starting 7 days before influenza infection.
- The study included intranasal infection with influenza virus followed by a secondary challenge with methicillin-resistant Staphylococcus aureus (MRSA).
- Finally, in sub-study, a total of three cohorts of hospitalized patients were evaluated to correlate eosinophil levels with antibiotic use, systemic inflammation, and outcomes.
TAKEAWAY:
- Antibiotic use during influenza infection impairs lung immunity, leading to increased lung eosinophils and reduced macrophage function.
- The study found that antibiotic treatment during influenza infection caused fungal dysbiosis, driving lung eosinophilia and impairing MRSA clearance.
- The detrimental effects of antibiotics on lung immunity were specific to the two-hit model of influenza followed by MRSA infection in mice.
- In hospitalized patients, eosinophil levels positively correlated with antibiotic use, systemic inflammation, and worsened outcomes.
IN PRACTICE:
“Our study highlights the pernicious effects of antibiotic use during viral infections and defines a mechanism whereby antibiotics perturb the gut mycobiome and result in lung eosinophilia. In turn, lung eosinophils, via release of MBP-1, suppress alveolar macrophage clearance of bacteria,” the authors of the study wrote.
SOURCE:
This study was led by Marilia Sanches Santos Rizzo Zuttion, Cedars-Sinai Medical Center in Los Angeles. It was published online in The Journal of Clinical Investigation.
LIMITATIONS:
This study’s limitations included the use of a murine model, which may not fully replicate human immune responses. Additionally, the study focused on a specific antibiotic cocktail, and results may vary with different antibiotics. The findings were also specific to the two-hit model of influenza followed by MRSA infection, limiting generalizability to other infections.
DISCLOSURES:
This study was supported by grants from the National Institutes of Health. Marilia Sanches Santos Rizzo Zuttion received research funding from Pfizer Inc. Additional disclosures are noted in the original article.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
How Effective Is the High-Dose Flu Vaccine in Older Adults?
How can the immunogenicity and effectiveness of flu vaccines be improved in older adults? Several strategies are available, one being the addition of an adjuvant. For example, the MF59-adjuvanted vaccine has shown superior immunogenicity. However, “we do not have data from controlled and randomized clinical trials showing superior clinical effectiveness versus the standard dose,” Professor Odile Launay, an infectious disease specialist at Cochin Hospital in Paris, France, noted during a press conference. Another option is to increase the antigen dose in the vaccine, creating a high-dose (HD) flu vaccine.
Why is there a need for an HD vaccine? “The elderly population bears the greatest burden from the flu,” explained Launay. “This is due to three factors: An aging immune system, a higher number of comorbidities, and increased frailty.” Standard-dose flu vaccines are seen as offering suboptimal protection for those older than 65 years, which led to the development of a quadrivalent vaccine with four times the antigen dose of standard flu vaccines. This HD vaccine was introduced in France during the 2021/2022 flu season. A real-world cohort study has since been conducted to evaluate its effectiveness in the target population — those aged 65 years or older. The results were recently published in Clinical Microbiology and Infection.
Cohort Study
The study included 405,385 noninstitutionalized people aged 65 years or older matched with 1,621,540 individuals in a 1:4 ratio. The first group received the HD vaccine, while the second group received the standard-dose vaccine. Both the groups had an average age of 77 years, with 56% women, and 51% vaccinated in pharmacies. The majority had been previously vaccinated against flu (91%), and 97% had completed a full COVID-19 vaccination schedule. More than half had at least one chronic illness.
Hospitalization rates for flu — the study’s primary outcome — were 69.5 vs 90.5 per 100,000 person-years in the HD vs standard-dose group. This represented a 23.3% reduction (95% CI, 8.4-35.8; P = .003).
Strengths and Limitations
Among the strengths of the study, Launay highlighted the large number of vaccinated participants older than 65 years — more than 7 million — and the widespread use of polymerase chain reaction flu tests in cases of hospitalization for respiratory infections, which improved flu coding in the database used. Additionally, the results were consistent with those of previous studies.
However, limitations included the retrospective design, which did not randomize participants and introduced potential bias. For example, the HD vaccine may have been prioritized for the oldest people or those with multiple comorbidities. Additionally, the 2021/2022 flu season was atypical, with the simultaneous circulation of the flu virus and SARS-CoV-2, as noted by Launay.
Conclusion
In conclusion, this first evaluation of the HD flu vaccine’s effectiveness in France showed a 25% reduction in hospitalizations, consistent with existing data covering 12 flu seasons. The vaccine has been available for a longer period in the United States and Northern Europe.
“The latest unpublished data from the 2022/23 season show a 27% reduction in hospitalizations with the HD vaccine in people over 65,” added Launay.
Note: Due to a pricing disagreement with the French government, Sanofi’s HD flu vaccine Efluelda, intended for people older than 65 years, will not be available this year. (See: Withdrawal of the Efluelda Influenza Vaccine: The Academy of Medicine Reacts). However, the company has submitted a dossier for a trivalent form for a return in the 2025/2026 season and is working on developing mRNA vaccines. Additionally, a combined flu/COVID-19 vaccine is currently in development.
The study was funded by Sanofi. Several authors are Sanofi employees. Odile Launay reported conflicts of interest with Sanofi, MSD, Pfizer, GSK, and Moderna.
This story was translated from Medscape’s French edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
How can the immunogenicity and effectiveness of flu vaccines be improved in older adults? Several strategies are available, one being the addition of an adjuvant. For example, the MF59-adjuvanted vaccine has shown superior immunogenicity. However, “we do not have data from controlled and randomized clinical trials showing superior clinical effectiveness versus the standard dose,” Professor Odile Launay, an infectious disease specialist at Cochin Hospital in Paris, France, noted during a press conference. Another option is to increase the antigen dose in the vaccine, creating a high-dose (HD) flu vaccine.
Why is there a need for an HD vaccine? “The elderly population bears the greatest burden from the flu,” explained Launay. “This is due to three factors: An aging immune system, a higher number of comorbidities, and increased frailty.” Standard-dose flu vaccines are seen as offering suboptimal protection for those older than 65 years, which led to the development of a quadrivalent vaccine with four times the antigen dose of standard flu vaccines. This HD vaccine was introduced in France during the 2021/2022 flu season. A real-world cohort study has since been conducted to evaluate its effectiveness in the target population — those aged 65 years or older. The results were recently published in Clinical Microbiology and Infection.
Cohort Study
The study included 405,385 noninstitutionalized people aged 65 years or older matched with 1,621,540 individuals in a 1:4 ratio. The first group received the HD vaccine, while the second group received the standard-dose vaccine. Both the groups had an average age of 77 years, with 56% women, and 51% vaccinated in pharmacies. The majority had been previously vaccinated against flu (91%), and 97% had completed a full COVID-19 vaccination schedule. More than half had at least one chronic illness.
Hospitalization rates for flu — the study’s primary outcome — were 69.5 vs 90.5 per 100,000 person-years in the HD vs standard-dose group. This represented a 23.3% reduction (95% CI, 8.4-35.8; P = .003).
Strengths and Limitations
Among the strengths of the study, Launay highlighted the large number of vaccinated participants older than 65 years — more than 7 million — and the widespread use of polymerase chain reaction flu tests in cases of hospitalization for respiratory infections, which improved flu coding in the database used. Additionally, the results were consistent with those of previous studies.
However, limitations included the retrospective design, which did not randomize participants and introduced potential bias. For example, the HD vaccine may have been prioritized for the oldest people or those with multiple comorbidities. Additionally, the 2021/2022 flu season was atypical, with the simultaneous circulation of the flu virus and SARS-CoV-2, as noted by Launay.
Conclusion
In conclusion, this first evaluation of the HD flu vaccine’s effectiveness in France showed a 25% reduction in hospitalizations, consistent with existing data covering 12 flu seasons. The vaccine has been available for a longer period in the United States and Northern Europe.
“The latest unpublished data from the 2022/23 season show a 27% reduction in hospitalizations with the HD vaccine in people over 65,” added Launay.
Note: Due to a pricing disagreement with the French government, Sanofi’s HD flu vaccine Efluelda, intended for people older than 65 years, will not be available this year. (See: Withdrawal of the Efluelda Influenza Vaccine: The Academy of Medicine Reacts). However, the company has submitted a dossier for a trivalent form for a return in the 2025/2026 season and is working on developing mRNA vaccines. Additionally, a combined flu/COVID-19 vaccine is currently in development.
The study was funded by Sanofi. Several authors are Sanofi employees. Odile Launay reported conflicts of interest with Sanofi, MSD, Pfizer, GSK, and Moderna.
This story was translated from Medscape’s French edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
How can the immunogenicity and effectiveness of flu vaccines be improved in older adults? Several strategies are available, one being the addition of an adjuvant. For example, the MF59-adjuvanted vaccine has shown superior immunogenicity. However, “we do not have data from controlled and randomized clinical trials showing superior clinical effectiveness versus the standard dose,” Professor Odile Launay, an infectious disease specialist at Cochin Hospital in Paris, France, noted during a press conference. Another option is to increase the antigen dose in the vaccine, creating a high-dose (HD) flu vaccine.
Why is there a need for an HD vaccine? “The elderly population bears the greatest burden from the flu,” explained Launay. “This is due to three factors: An aging immune system, a higher number of comorbidities, and increased frailty.” Standard-dose flu vaccines are seen as offering suboptimal protection for those older than 65 years, which led to the development of a quadrivalent vaccine with four times the antigen dose of standard flu vaccines. This HD vaccine was introduced in France during the 2021/2022 flu season. A real-world cohort study has since been conducted to evaluate its effectiveness in the target population — those aged 65 years or older. The results were recently published in Clinical Microbiology and Infection.
Cohort Study
The study included 405,385 noninstitutionalized people aged 65 years or older matched with 1,621,540 individuals in a 1:4 ratio. The first group received the HD vaccine, while the second group received the standard-dose vaccine. Both the groups had an average age of 77 years, with 56% women, and 51% vaccinated in pharmacies. The majority had been previously vaccinated against flu (91%), and 97% had completed a full COVID-19 vaccination schedule. More than half had at least one chronic illness.
Hospitalization rates for flu — the study’s primary outcome — were 69.5 vs 90.5 per 100,000 person-years in the HD vs standard-dose group. This represented a 23.3% reduction (95% CI, 8.4-35.8; P = .003).
Strengths and Limitations
Among the strengths of the study, Launay highlighted the large number of vaccinated participants older than 65 years — more than 7 million — and the widespread use of polymerase chain reaction flu tests in cases of hospitalization for respiratory infections, which improved flu coding in the database used. Additionally, the results were consistent with those of previous studies.
However, limitations included the retrospective design, which did not randomize participants and introduced potential bias. For example, the HD vaccine may have been prioritized for the oldest people or those with multiple comorbidities. Additionally, the 2021/2022 flu season was atypical, with the simultaneous circulation of the flu virus and SARS-CoV-2, as noted by Launay.
Conclusion
In conclusion, this first evaluation of the HD flu vaccine’s effectiveness in France showed a 25% reduction in hospitalizations, consistent with existing data covering 12 flu seasons. The vaccine has been available for a longer period in the United States and Northern Europe.
“The latest unpublished data from the 2022/23 season show a 27% reduction in hospitalizations with the HD vaccine in people over 65,” added Launay.
Note: Due to a pricing disagreement with the French government, Sanofi’s HD flu vaccine Efluelda, intended for people older than 65 years, will not be available this year. (See: Withdrawal of the Efluelda Influenza Vaccine: The Academy of Medicine Reacts). However, the company has submitted a dossier for a trivalent form for a return in the 2025/2026 season and is working on developing mRNA vaccines. Additionally, a combined flu/COVID-19 vaccine is currently in development.
The study was funded by Sanofi. Several authors are Sanofi employees. Odile Launay reported conflicts of interest with Sanofi, MSD, Pfizer, GSK, and Moderna.
This story was translated from Medscape’s French edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
Public Health, Not Politics, Should Drive Mask Policies, Says Ethicist
This transcript has been edited for clarity.
I recently saw a ban that has me very worried, concerned, and strongly in opposition.
Basically, the standard kind of medical mask would be captured, although I think their aim in doing this was to try to discourage people at political protests from being able to wear masks and hide their identity. They’re basically trying to discourage that. This is particularly triggered by, I think, protests about the invasion of Israel, the war that resulted in Gaza, and the demonstrations that have gone on around the country, with many people masked.
There may be issues about what is acceptable to wear when you go to a demonstration. I don’t claim to know about the civil rights of that.
In a time at which COVID-19 is flourishing, really on the rebound, expanding fast, and still causing 600 deaths a week; the flu season is going to be upon us soon enough; and there are also concerns about the possibility of avian flu jumping into the human population, it is absolutely the wrong time to single out those who are trying to mask for health reasons.
Basically, there are two strong reasons. One, there are people out there who wear a medical mask or mask for a medical reason because they have an underlying disease. They may have had a transplant or they may feel they’re immunocompromised for some reason. They worry that, if they don’t wear a mask, they’re going to get an infection from something like COVID-19 or flu, which could really be super-dangerous for them.
The other reason people mask is to protect their family members. They may have someone who’s immunocompromised in the family, or they’re doing it kindly and altruistically to protect the rest of us and to stop viruses from circulating.
These bans are not taking into account public health. They’re being brought forward in the midst of political heat about demonstrations and political issues. I think they should be opposed. I do not think they should be enacted.
I think the medical rights of people with disabilities and immunologic disorders, and those who want to mask to prevent getting sick at a time at which infectious diseases are still circulating and killing people, ought to take priority. Public health, in this case, should drive our policies about masks.
Dr. Caplan, director, Division of Medical Ethics, New York University Langone Medical Center, New York, NY, served on Johnson & Johnson’s Panel for Compassionate Drug Use (unpaid position), and is a contributing author and adviser for Medscape.
A version of this article appeared on Medscape.com.
This transcript has been edited for clarity.
I recently saw a ban that has me very worried, concerned, and strongly in opposition.
Basically, the standard kind of medical mask would be captured, although I think their aim in doing this was to try to discourage people at political protests from being able to wear masks and hide their identity. They’re basically trying to discourage that. This is particularly triggered by, I think, protests about the invasion of Israel, the war that resulted in Gaza, and the demonstrations that have gone on around the country, with many people masked.
There may be issues about what is acceptable to wear when you go to a demonstration. I don’t claim to know about the civil rights of that.
In a time at which COVID-19 is flourishing, really on the rebound, expanding fast, and still causing 600 deaths a week; the flu season is going to be upon us soon enough; and there are also concerns about the possibility of avian flu jumping into the human population, it is absolutely the wrong time to single out those who are trying to mask for health reasons.
Basically, there are two strong reasons. One, there are people out there who wear a medical mask or mask for a medical reason because they have an underlying disease. They may have had a transplant or they may feel they’re immunocompromised for some reason. They worry that, if they don’t wear a mask, they’re going to get an infection from something like COVID-19 or flu, which could really be super-dangerous for them.
The other reason people mask is to protect their family members. They may have someone who’s immunocompromised in the family, or they’re doing it kindly and altruistically to protect the rest of us and to stop viruses from circulating.
These bans are not taking into account public health. They’re being brought forward in the midst of political heat about demonstrations and political issues. I think they should be opposed. I do not think they should be enacted.
I think the medical rights of people with disabilities and immunologic disorders, and those who want to mask to prevent getting sick at a time at which infectious diseases are still circulating and killing people, ought to take priority. Public health, in this case, should drive our policies about masks.
Dr. Caplan, director, Division of Medical Ethics, New York University Langone Medical Center, New York, NY, served on Johnson & Johnson’s Panel for Compassionate Drug Use (unpaid position), and is a contributing author and adviser for Medscape.
A version of this article appeared on Medscape.com.
This transcript has been edited for clarity.
I recently saw a ban that has me very worried, concerned, and strongly in opposition.
Basically, the standard kind of medical mask would be captured, although I think their aim in doing this was to try to discourage people at political protests from being able to wear masks and hide their identity. They’re basically trying to discourage that. This is particularly triggered by, I think, protests about the invasion of Israel, the war that resulted in Gaza, and the demonstrations that have gone on around the country, with many people masked.
There may be issues about what is acceptable to wear when you go to a demonstration. I don’t claim to know about the civil rights of that.
In a time at which COVID-19 is flourishing, really on the rebound, expanding fast, and still causing 600 deaths a week; the flu season is going to be upon us soon enough; and there are also concerns about the possibility of avian flu jumping into the human population, it is absolutely the wrong time to single out those who are trying to mask for health reasons.
Basically, there are two strong reasons. One, there are people out there who wear a medical mask or mask for a medical reason because they have an underlying disease. They may have had a transplant or they may feel they’re immunocompromised for some reason. They worry that, if they don’t wear a mask, they’re going to get an infection from something like COVID-19 or flu, which could really be super-dangerous for them.
The other reason people mask is to protect their family members. They may have someone who’s immunocompromised in the family, or they’re doing it kindly and altruistically to protect the rest of us and to stop viruses from circulating.
These bans are not taking into account public health. They’re being brought forward in the midst of political heat about demonstrations and political issues. I think they should be opposed. I do not think they should be enacted.
I think the medical rights of people with disabilities and immunologic disorders, and those who want to mask to prevent getting sick at a time at which infectious diseases are still circulating and killing people, ought to take priority. Public health, in this case, should drive our policies about masks.
Dr. Caplan, director, Division of Medical Ethics, New York University Langone Medical Center, New York, NY, served on Johnson & Johnson’s Panel for Compassionate Drug Use (unpaid position), and is a contributing author and adviser for Medscape.
A version of this article appeared on Medscape.com.
How Experts Predicts This COVID and Flu Season Will Unfold
What’s the outlook for COVID-19 and flu this fall and winter? It’ll probably be a lot like last year, experts say.
“We currently expect this flu season to be comparable to last year’s season,” said Adrienne Keen, PhD, of the Centers for Disease Control and Prevention’s (CDC) Center for Forecasting and Outbreak Analytics. “We expect this year’s COVID-19 season peak to be similar to last year’s or lower.” The CDC is still analyzing COVID surveillance data from the summer and will update the forecast as more is learned.
For COVID, that means it won’t be as bad as the pandemic years, and for the flu, it’s a typical pre-pandemic season. But status quo does not mean great.
Between October 2023 and April 2024, as many as 75 million people got the flu in the United States, according to CDC estimates, resulting in up to 900,000 hospitalizations and between 17,000 and 100,000 deaths. In 2023, about 900,000 Americans were hospitalized with COVID and 75,000 died.
Getting vaccinated remains crucial, public health officials stressed.
Predicting COVID
Two key predictors of how bad an upcoming COVID season will be are the cycling of new variants and the population’s immunity (protection from an infectious disease that happens when a population is immune through vaccination or previous infection).
When new variants go up and immunity goes down, “we tend to see the increase in cases,” said Michael T. Osterholm, PhD, MPH, director of the Center for Infectious Disease Research and Policy and a professor of public health at the University of Minnesota, Minneapolis. But if the number of variants goes down and immunity levels go up, the outlook is more favorable.
The new COVID variant called XEC has been found in at least 25 states. On September 27, the CDC added the variant to the COVID tracker. It now accounts for 6% of US cases. This was expected, as the variant has been circulating in Europe, said Amesh Adalja, MD, a senior scholar and infectious disease expert at the Center for Health Security at Johns Hopkins University, Baltimore, Maryland.
“There will always be a new variant appearing, and one falling,” he said. “So the fact that this is happening is not surprising.”
Meanwhile, the summer COVID surge has provided postinfection immunity for some people. “What’s likely is, we are going to see substantial protection of the population for several months based on previous infection and in some cases vaccination,” Dr. Osterholm said. That means protection from serious illness, hospitalizations, and deaths (but not necessarily infection). That protection could last through the year or into early 2025.
The timing of 2024’s winter surge will likely be a bit later than 2023’s, said Andrew Pekosz, PhD, a professor and vice chair of molecular microbiology and immunology at Johns Hopkins University, Baltimore, “peaking just after the Christmas/New Year holiday.”
During the 2023-2024 season, weekly COVID hospitalizations peaked the week of Dec. 30, said Justin Lessler, PhD, a professor of epidemiology at the University of North Carolina at Chapel Hill and a member of the COVID-19 Scenario Modeling Hub.
But variants are unpredictable. “There’s a chance that the XEC variant may take off and spread, or might not,” said Dr. Adalja. As of September 28, the Omicron variant KP.3.1.1 was leading, accounting for 58.7% of US cases, according to the CDC.
While Dr. Adalja agreed that 2024’s COVID season will probably be like 2023’s, “we have to be prepared for cases and hospitalizations going up,” he said, “but not to the point of a crisis.” A return to lockdowns and social distancing is unlikely.
Still, older adults and others at higher risk of getting very sick from COVID should consider masking during travel, said Rajendram Rajnarayanan, PhD, MSc, an associate professor at the New York Institute of Technology College of Osteopathic Medicine at Arkansas State University, Jonesboro.
Flu Forecasts
Predicting flu season this early is hard, said Jeffrey Shaman, PhD, a professor of environmental health sciences and professor of climate at Colombia University, New York.
“You can look at the CDC forecast and use it as a very loose guide right now,” said Dr. Shaman, who won the CDC’s first “Predict the Influenza Season Challenge” in 2014. “Until there is actually flu, it’s like trying to predict the landfall of a hurricane.” Flu activity remained low as of September 14 (the most current data available), according to the CDC.
When flu activity picks up, typically in mid-October or November, experts look at the dominant strain, exposure to similar strains in previous years, and how well-matched the current flu vaccine is to that dominant strain, Dr. Shaman said. Vaccine makers must make an educated guess months in advance regarding which strain to target, to allow time for production.
The vaccination rate plays a role, too, but that tends to remain constant, Dr. Shaman said. According to the CDC, less than half of adults age 18 and up got a flu vaccination last year.
Experts also consider flu patterns in the Southern Hemisphere, where 2024 flu activity has mostly involved two subtypes of influenza A — H1N1 and H3N2 — and some influenza B, the CDC found.
How Well Do This Year’s Vaccines and Viruses Match Up?
The FDA has authorized three updated COVID vaccines for this fall. Novavax targets the JN.1 strain of SARS-CoV-2, the virus that causes COVID-19. Both mRNA vaccines, Moderna and Pfizer, target KP.2, a descendant of JN.1. All three target current predominant variants, and any one of them is recommended by the CDC.
The vaccines are a good “though not perfect match to virtually all the circulating variants of SARS-CoV-2,” said Dr. Pekosz.
Experts said that the shots will protect against the XEC variant.
“XEC and its sublineages are expected to be the dominant fall/winter variant group,” said Dr. Rajnarayanan.
This year’s flu vaccines, all trivalent (protecting against three viruses), will target the three strains expected to circulate — H1N1, H3N2, and influenza B (Victoria), according to the CDC.
People should still get vaccinated, Dr. Adalja said, and use home tests for flu and COVID and take antivirals promptly when needed. The goal should not be status quo but rather fewer COVID and flu hospitalizations and deaths.
A version of this article first appeared on WebMD.com.
What’s the outlook for COVID-19 and flu this fall and winter? It’ll probably be a lot like last year, experts say.
“We currently expect this flu season to be comparable to last year’s season,” said Adrienne Keen, PhD, of the Centers for Disease Control and Prevention’s (CDC) Center for Forecasting and Outbreak Analytics. “We expect this year’s COVID-19 season peak to be similar to last year’s or lower.” The CDC is still analyzing COVID surveillance data from the summer and will update the forecast as more is learned.
For COVID, that means it won’t be as bad as the pandemic years, and for the flu, it’s a typical pre-pandemic season. But status quo does not mean great.
Between October 2023 and April 2024, as many as 75 million people got the flu in the United States, according to CDC estimates, resulting in up to 900,000 hospitalizations and between 17,000 and 100,000 deaths. In 2023, about 900,000 Americans were hospitalized with COVID and 75,000 died.
Getting vaccinated remains crucial, public health officials stressed.
Predicting COVID
Two key predictors of how bad an upcoming COVID season will be are the cycling of new variants and the population’s immunity (protection from an infectious disease that happens when a population is immune through vaccination or previous infection).
When new variants go up and immunity goes down, “we tend to see the increase in cases,” said Michael T. Osterholm, PhD, MPH, director of the Center for Infectious Disease Research and Policy and a professor of public health at the University of Minnesota, Minneapolis. But if the number of variants goes down and immunity levels go up, the outlook is more favorable.
The new COVID variant called XEC has been found in at least 25 states. On September 27, the CDC added the variant to the COVID tracker. It now accounts for 6% of US cases. This was expected, as the variant has been circulating in Europe, said Amesh Adalja, MD, a senior scholar and infectious disease expert at the Center for Health Security at Johns Hopkins University, Baltimore, Maryland.
“There will always be a new variant appearing, and one falling,” he said. “So the fact that this is happening is not surprising.”
Meanwhile, the summer COVID surge has provided postinfection immunity for some people. “What’s likely is, we are going to see substantial protection of the population for several months based on previous infection and in some cases vaccination,” Dr. Osterholm said. That means protection from serious illness, hospitalizations, and deaths (but not necessarily infection). That protection could last through the year or into early 2025.
The timing of 2024’s winter surge will likely be a bit later than 2023’s, said Andrew Pekosz, PhD, a professor and vice chair of molecular microbiology and immunology at Johns Hopkins University, Baltimore, “peaking just after the Christmas/New Year holiday.”
During the 2023-2024 season, weekly COVID hospitalizations peaked the week of Dec. 30, said Justin Lessler, PhD, a professor of epidemiology at the University of North Carolina at Chapel Hill and a member of the COVID-19 Scenario Modeling Hub.
But variants are unpredictable. “There’s a chance that the XEC variant may take off and spread, or might not,” said Dr. Adalja. As of September 28, the Omicron variant KP.3.1.1 was leading, accounting for 58.7% of US cases, according to the CDC.
While Dr. Adalja agreed that 2024’s COVID season will probably be like 2023’s, “we have to be prepared for cases and hospitalizations going up,” he said, “but not to the point of a crisis.” A return to lockdowns and social distancing is unlikely.
Still, older adults and others at higher risk of getting very sick from COVID should consider masking during travel, said Rajendram Rajnarayanan, PhD, MSc, an associate professor at the New York Institute of Technology College of Osteopathic Medicine at Arkansas State University, Jonesboro.
Flu Forecasts
Predicting flu season this early is hard, said Jeffrey Shaman, PhD, a professor of environmental health sciences and professor of climate at Colombia University, New York.
“You can look at the CDC forecast and use it as a very loose guide right now,” said Dr. Shaman, who won the CDC’s first “Predict the Influenza Season Challenge” in 2014. “Until there is actually flu, it’s like trying to predict the landfall of a hurricane.” Flu activity remained low as of September 14 (the most current data available), according to the CDC.
When flu activity picks up, typically in mid-October or November, experts look at the dominant strain, exposure to similar strains in previous years, and how well-matched the current flu vaccine is to that dominant strain, Dr. Shaman said. Vaccine makers must make an educated guess months in advance regarding which strain to target, to allow time for production.
The vaccination rate plays a role, too, but that tends to remain constant, Dr. Shaman said. According to the CDC, less than half of adults age 18 and up got a flu vaccination last year.
Experts also consider flu patterns in the Southern Hemisphere, where 2024 flu activity has mostly involved two subtypes of influenza A — H1N1 and H3N2 — and some influenza B, the CDC found.
How Well Do This Year’s Vaccines and Viruses Match Up?
The FDA has authorized three updated COVID vaccines for this fall. Novavax targets the JN.1 strain of SARS-CoV-2, the virus that causes COVID-19. Both mRNA vaccines, Moderna and Pfizer, target KP.2, a descendant of JN.1. All three target current predominant variants, and any one of them is recommended by the CDC.
The vaccines are a good “though not perfect match to virtually all the circulating variants of SARS-CoV-2,” said Dr. Pekosz.
Experts said that the shots will protect against the XEC variant.
“XEC and its sublineages are expected to be the dominant fall/winter variant group,” said Dr. Rajnarayanan.
This year’s flu vaccines, all trivalent (protecting against three viruses), will target the three strains expected to circulate — H1N1, H3N2, and influenza B (Victoria), according to the CDC.
People should still get vaccinated, Dr. Adalja said, and use home tests for flu and COVID and take antivirals promptly when needed. The goal should not be status quo but rather fewer COVID and flu hospitalizations and deaths.
A version of this article first appeared on WebMD.com.
What’s the outlook for COVID-19 and flu this fall and winter? It’ll probably be a lot like last year, experts say.
“We currently expect this flu season to be comparable to last year’s season,” said Adrienne Keen, PhD, of the Centers for Disease Control and Prevention’s (CDC) Center for Forecasting and Outbreak Analytics. “We expect this year’s COVID-19 season peak to be similar to last year’s or lower.” The CDC is still analyzing COVID surveillance data from the summer and will update the forecast as more is learned.
For COVID, that means it won’t be as bad as the pandemic years, and for the flu, it’s a typical pre-pandemic season. But status quo does not mean great.
Between October 2023 and April 2024, as many as 75 million people got the flu in the United States, according to CDC estimates, resulting in up to 900,000 hospitalizations and between 17,000 and 100,000 deaths. In 2023, about 900,000 Americans were hospitalized with COVID and 75,000 died.
Getting vaccinated remains crucial, public health officials stressed.
Predicting COVID
Two key predictors of how bad an upcoming COVID season will be are the cycling of new variants and the population’s immunity (protection from an infectious disease that happens when a population is immune through vaccination or previous infection).
When new variants go up and immunity goes down, “we tend to see the increase in cases,” said Michael T. Osterholm, PhD, MPH, director of the Center for Infectious Disease Research and Policy and a professor of public health at the University of Minnesota, Minneapolis. But if the number of variants goes down and immunity levels go up, the outlook is more favorable.
The new COVID variant called XEC has been found in at least 25 states. On September 27, the CDC added the variant to the COVID tracker. It now accounts for 6% of US cases. This was expected, as the variant has been circulating in Europe, said Amesh Adalja, MD, a senior scholar and infectious disease expert at the Center for Health Security at Johns Hopkins University, Baltimore, Maryland.
“There will always be a new variant appearing, and one falling,” he said. “So the fact that this is happening is not surprising.”
Meanwhile, the summer COVID surge has provided postinfection immunity for some people. “What’s likely is, we are going to see substantial protection of the population for several months based on previous infection and in some cases vaccination,” Dr. Osterholm said. That means protection from serious illness, hospitalizations, and deaths (but not necessarily infection). That protection could last through the year or into early 2025.
The timing of 2024’s winter surge will likely be a bit later than 2023’s, said Andrew Pekosz, PhD, a professor and vice chair of molecular microbiology and immunology at Johns Hopkins University, Baltimore, “peaking just after the Christmas/New Year holiday.”
During the 2023-2024 season, weekly COVID hospitalizations peaked the week of Dec. 30, said Justin Lessler, PhD, a professor of epidemiology at the University of North Carolina at Chapel Hill and a member of the COVID-19 Scenario Modeling Hub.
But variants are unpredictable. “There’s a chance that the XEC variant may take off and spread, or might not,” said Dr. Adalja. As of September 28, the Omicron variant KP.3.1.1 was leading, accounting for 58.7% of US cases, according to the CDC.
While Dr. Adalja agreed that 2024’s COVID season will probably be like 2023’s, “we have to be prepared for cases and hospitalizations going up,” he said, “but not to the point of a crisis.” A return to lockdowns and social distancing is unlikely.
Still, older adults and others at higher risk of getting very sick from COVID should consider masking during travel, said Rajendram Rajnarayanan, PhD, MSc, an associate professor at the New York Institute of Technology College of Osteopathic Medicine at Arkansas State University, Jonesboro.
Flu Forecasts
Predicting flu season this early is hard, said Jeffrey Shaman, PhD, a professor of environmental health sciences and professor of climate at Colombia University, New York.
“You can look at the CDC forecast and use it as a very loose guide right now,” said Dr. Shaman, who won the CDC’s first “Predict the Influenza Season Challenge” in 2014. “Until there is actually flu, it’s like trying to predict the landfall of a hurricane.” Flu activity remained low as of September 14 (the most current data available), according to the CDC.
When flu activity picks up, typically in mid-October or November, experts look at the dominant strain, exposure to similar strains in previous years, and how well-matched the current flu vaccine is to that dominant strain, Dr. Shaman said. Vaccine makers must make an educated guess months in advance regarding which strain to target, to allow time for production.
The vaccination rate plays a role, too, but that tends to remain constant, Dr. Shaman said. According to the CDC, less than half of adults age 18 and up got a flu vaccination last year.
Experts also consider flu patterns in the Southern Hemisphere, where 2024 flu activity has mostly involved two subtypes of influenza A — H1N1 and H3N2 — and some influenza B, the CDC found.
How Well Do This Year’s Vaccines and Viruses Match Up?
The FDA has authorized three updated COVID vaccines for this fall. Novavax targets the JN.1 strain of SARS-CoV-2, the virus that causes COVID-19. Both mRNA vaccines, Moderna and Pfizer, target KP.2, a descendant of JN.1. All three target current predominant variants, and any one of them is recommended by the CDC.
The vaccines are a good “though not perfect match to virtually all the circulating variants of SARS-CoV-2,” said Dr. Pekosz.
Experts said that the shots will protect against the XEC variant.
“XEC and its sublineages are expected to be the dominant fall/winter variant group,” said Dr. Rajnarayanan.
This year’s flu vaccines, all trivalent (protecting against three viruses), will target the three strains expected to circulate — H1N1, H3N2, and influenza B (Victoria), according to the CDC.
People should still get vaccinated, Dr. Adalja said, and use home tests for flu and COVID and take antivirals promptly when needed. The goal should not be status quo but rather fewer COVID and flu hospitalizations and deaths.
A version of this article first appeared on WebMD.com.
Guidance for Practicing Primary Care: World Health Organization’s Updated Influenza Guidelines for 2024
As primary care physicians, we are often the first ones patients see when they become infected with influenza. According to Centers for Disease Control and Prevention statistics, approximately 5%-20% of the US population will be infected with influenza every year. Additionally, more than 200,000 of these patients will be hospitalized because of complications related to influenza.
Earlier in September, the World Health Organization (WHO) issued its latest clinical practice guidelines for influenza for the 2024-2025 season. This is a 213-page document aimed at healthcare providers who treat patients infected with influenza. It includes treatment for those with severe and nonsevere influenza infections, those in both the outpatient and hospitalized setting, as well as medication prophylaxis for those exposed to the virus. Additionally, it defines risk estimates for those who are at risk of being hospitalized or dying. In contrast, previous updates focused on management of severe influenza or those at risk of severe influenza.
These guidelines cover recommendations regarding all the antiviral medications for treating influenza used around the world. For the purpose of this article, we will focus on those most commonly used in the United States.
A newer medication discussed was baloxavir. It is recommended to be used for patients with nonsevere influenza who are at high risk for progression to severe disease. The advice is to not use it for those with little risk of progression to severe disease. Oseltamivir is recommended for those with severe infection.
The guidelines recommend against using antibiotics for those who have a low likelihood of having a bacterial coinfection. As primary care doctors, we often prescribe medications to help with symptoms. These guidelines recommend against the use of corticosteroids and antibiotics but did advise that NSAIDs could be used for symptom relief.
One of the important parts of these guidelines is prevention in patients who have been exposed but are asymptomatic. They recommend baloxavir or oseltamivir but only for those patients who are at high risk of being hospitalized if they were to become infected. Any of the antivirals can be used for patients who are exposed to the novel influenza A, which is associated with a higher mortality rate. Caution when prescribing antivirals is recommended in immunocompromised patients because there is more drug resistance seen in these patients.
These updates also discuss the use of different influenza tests. In the outpatient setting, primary doctors don’t have time for test results that may take 2 days to come back. Only rapid tests make the sense in the primary care setting. Additionally, in the age of COVID, it is important to make an accurate diagnosis so we should be testing patients. There is resistance seen with the antivirals we prescribe for influenza so prescribing them empirically without a confirmed diagnosis of influenza may be doing more harm than good.
One gap in these recommendations is vaccination. This topic was not covered at all. It would be helpful to have a strategy in place to prevent infection in populations rather than focusing just on exposed individuals. A discussion of when and who and to vaccinate would be helpful. Research into the effectiveness of vaccines is key and more accurate development of a season’s influenza vaccine would be beneficial. Currently, there is much vaccine misinformation being spread around. Education and information regarding influenza vaccines, especially coming from WHO, is crucial.
Another failure of these recommendations is that the guidelines apply only to those who present within a few days of becoming symptomatic. As family doctors, we know many of our patients self-treat or consult Google. They often don’t come for medical care until they’ve been sick for a week or longer. There are no guidelines for these patients.
In general, these guidelines are comprehensive and do a great job discussing the current medications available. However, more is needed to increase vaccination rates. Patients need to know that if they may be sick with influenza, they need to seek medical care as soon as possible. We, as family doctors, need to do a better job of risk-stratifying our patients and prescribing prophylactic medication when suitable. Every infection we prevent aids in the health of our community and the global population at large.
Dr. Girgis practices family medicine in South River, New Jersey, and is a clinical assistant professor of family medicine at Robert Wood Johnson Medical School, New Brunswick, New Jersey. She has no relevant conflicts of interest.
As primary care physicians, we are often the first ones patients see when they become infected with influenza. According to Centers for Disease Control and Prevention statistics, approximately 5%-20% of the US population will be infected with influenza every year. Additionally, more than 200,000 of these patients will be hospitalized because of complications related to influenza.
Earlier in September, the World Health Organization (WHO) issued its latest clinical practice guidelines for influenza for the 2024-2025 season. This is a 213-page document aimed at healthcare providers who treat patients infected with influenza. It includes treatment for those with severe and nonsevere influenza infections, those in both the outpatient and hospitalized setting, as well as medication prophylaxis for those exposed to the virus. Additionally, it defines risk estimates for those who are at risk of being hospitalized or dying. In contrast, previous updates focused on management of severe influenza or those at risk of severe influenza.
These guidelines cover recommendations regarding all the antiviral medications for treating influenza used around the world. For the purpose of this article, we will focus on those most commonly used in the United States.
A newer medication discussed was baloxavir. It is recommended to be used for patients with nonsevere influenza who are at high risk for progression to severe disease. The advice is to not use it for those with little risk of progression to severe disease. Oseltamivir is recommended for those with severe infection.
The guidelines recommend against using antibiotics for those who have a low likelihood of having a bacterial coinfection. As primary care doctors, we often prescribe medications to help with symptoms. These guidelines recommend against the use of corticosteroids and antibiotics but did advise that NSAIDs could be used for symptom relief.
One of the important parts of these guidelines is prevention in patients who have been exposed but are asymptomatic. They recommend baloxavir or oseltamivir but only for those patients who are at high risk of being hospitalized if they were to become infected. Any of the antivirals can be used for patients who are exposed to the novel influenza A, which is associated with a higher mortality rate. Caution when prescribing antivirals is recommended in immunocompromised patients because there is more drug resistance seen in these patients.
These updates also discuss the use of different influenza tests. In the outpatient setting, primary doctors don’t have time for test results that may take 2 days to come back. Only rapid tests make the sense in the primary care setting. Additionally, in the age of COVID, it is important to make an accurate diagnosis so we should be testing patients. There is resistance seen with the antivirals we prescribe for influenza so prescribing them empirically without a confirmed diagnosis of influenza may be doing more harm than good.
One gap in these recommendations is vaccination. This topic was not covered at all. It would be helpful to have a strategy in place to prevent infection in populations rather than focusing just on exposed individuals. A discussion of when and who and to vaccinate would be helpful. Research into the effectiveness of vaccines is key and more accurate development of a season’s influenza vaccine would be beneficial. Currently, there is much vaccine misinformation being spread around. Education and information regarding influenza vaccines, especially coming from WHO, is crucial.
Another failure of these recommendations is that the guidelines apply only to those who present within a few days of becoming symptomatic. As family doctors, we know many of our patients self-treat or consult Google. They often don’t come for medical care until they’ve been sick for a week or longer. There are no guidelines for these patients.
In general, these guidelines are comprehensive and do a great job discussing the current medications available. However, more is needed to increase vaccination rates. Patients need to know that if they may be sick with influenza, they need to seek medical care as soon as possible. We, as family doctors, need to do a better job of risk-stratifying our patients and prescribing prophylactic medication when suitable. Every infection we prevent aids in the health of our community and the global population at large.
Dr. Girgis practices family medicine in South River, New Jersey, and is a clinical assistant professor of family medicine at Robert Wood Johnson Medical School, New Brunswick, New Jersey. She has no relevant conflicts of interest.
As primary care physicians, we are often the first ones patients see when they become infected with influenza. According to Centers for Disease Control and Prevention statistics, approximately 5%-20% of the US population will be infected with influenza every year. Additionally, more than 200,000 of these patients will be hospitalized because of complications related to influenza.
Earlier in September, the World Health Organization (WHO) issued its latest clinical practice guidelines for influenza for the 2024-2025 season. This is a 213-page document aimed at healthcare providers who treat patients infected with influenza. It includes treatment for those with severe and nonsevere influenza infections, those in both the outpatient and hospitalized setting, as well as medication prophylaxis for those exposed to the virus. Additionally, it defines risk estimates for those who are at risk of being hospitalized or dying. In contrast, previous updates focused on management of severe influenza or those at risk of severe influenza.
These guidelines cover recommendations regarding all the antiviral medications for treating influenza used around the world. For the purpose of this article, we will focus on those most commonly used in the United States.
A newer medication discussed was baloxavir. It is recommended to be used for patients with nonsevere influenza who are at high risk for progression to severe disease. The advice is to not use it for those with little risk of progression to severe disease. Oseltamivir is recommended for those with severe infection.
The guidelines recommend against using antibiotics for those who have a low likelihood of having a bacterial coinfection. As primary care doctors, we often prescribe medications to help with symptoms. These guidelines recommend against the use of corticosteroids and antibiotics but did advise that NSAIDs could be used for symptom relief.
One of the important parts of these guidelines is prevention in patients who have been exposed but are asymptomatic. They recommend baloxavir or oseltamivir but only for those patients who are at high risk of being hospitalized if they were to become infected. Any of the antivirals can be used for patients who are exposed to the novel influenza A, which is associated with a higher mortality rate. Caution when prescribing antivirals is recommended in immunocompromised patients because there is more drug resistance seen in these patients.
These updates also discuss the use of different influenza tests. In the outpatient setting, primary doctors don’t have time for test results that may take 2 days to come back. Only rapid tests make the sense in the primary care setting. Additionally, in the age of COVID, it is important to make an accurate diagnosis so we should be testing patients. There is resistance seen with the antivirals we prescribe for influenza so prescribing them empirically without a confirmed diagnosis of influenza may be doing more harm than good.
One gap in these recommendations is vaccination. This topic was not covered at all. It would be helpful to have a strategy in place to prevent infection in populations rather than focusing just on exposed individuals. A discussion of when and who and to vaccinate would be helpful. Research into the effectiveness of vaccines is key and more accurate development of a season’s influenza vaccine would be beneficial. Currently, there is much vaccine misinformation being spread around. Education and information regarding influenza vaccines, especially coming from WHO, is crucial.
Another failure of these recommendations is that the guidelines apply only to those who present within a few days of becoming symptomatic. As family doctors, we know many of our patients self-treat or consult Google. They often don’t come for medical care until they’ve been sick for a week or longer. There are no guidelines for these patients.
In general, these guidelines are comprehensive and do a great job discussing the current medications available. However, more is needed to increase vaccination rates. Patients need to know that if they may be sick with influenza, they need to seek medical care as soon as possible. We, as family doctors, need to do a better job of risk-stratifying our patients and prescribing prophylactic medication when suitable. Every infection we prevent aids in the health of our community and the global population at large.
Dr. Girgis practices family medicine in South River, New Jersey, and is a clinical assistant professor of family medicine at Robert Wood Johnson Medical School, New Brunswick, New Jersey. She has no relevant conflicts of interest.