HPV Vaccine Does Not Seem to Increase Guillain-Barré Risk

The human papillomavirus vaccine does not appear to increase the risk of developing Guillain-Barré syndrome, despite isolated reports of the condition following vaccination, a study shows.

“I found that there's some overlap between the incidence of Guillain-Barré in the general population and Guillain-Barré after vaccination with Gardasil,” Dr. Nizar Souayah said in an interview. However, he and his colleagues have not found Guillain-Barré to occur more often among those who have received the HPV vaccine than among people in the general population.

Dr. Souayah will be presenting the study at the American Academy of Neurology annual meeting in Seattle, April 25-May 2. The data were released early.

The Food and Drug Administration approved the vaccine in 2006 for use in girls and women aged 9–26 years to prevent infection against HPV strains 16 and 18, which cause most cervical cancers, and strains 6 and 11, which are responsible for most genital warts in the United States. Since the approval of Gardasil, more than 16 million doses have been given. There have been isolated reports of Guillain-Barré syndrome (GBS) after receiving the vaccine.

Dr. Souayah and his colleagues used data from the Vaccine Adverse Event Reporting System, which is a cooperative program for vaccine safety of the Centers for Disease Control and Prevention and the FDA. The system is a postmarketing safety surveillance program that collects information about adverse events that occur after the administration of U.S.-licensed vaccines.

Dr. Souayah searched the database using several key words: “numbness,” “tingling,” “Guillain,” “Barré,” and “Guillain-Barré syndrome.” He identified roughly 350 patients. He then reviewed the data for each of these patients and characterized them as highly likely to have GBS, highly unlikely to have GBS, and unclear. He and his colleagues included in this analysis only those patients considered to be highly likely to have GBS.

They found 36 reported cases of GBS after vaccination with the HPV vaccine in 2006–2008. The mean age was 17 years. The estimated incidence of GBS after vaccination is 7 cases per million vaccinations. In comparison, the estimated incidence for the general population is 4–10 cases per million individuals.

“The most striking data [are] that most of the Guillain-Barré syndrome cases occurred within 6 weeks of vaccination,” said Dr. Souayah, of the departments of neurology and neurosciences at the University of Medicine and Dentistry of New Jersey, Newark. The onset of GBS occurred within 6 weeks of vaccination in 75% of the individuals for whom the vaccination date was known.

“Our results show that Guillain-Barré is not occurring more often after HPV vaccination than it does in the general population. However, the fact that most of these cases occurred within 6 weeks of vaccination does warrant careful monitoring for any additional cases and continued analysis,” he said in a statement.

He urged caution in interpreting the results. The database may not contain all cases of GBS after administration of the HPV vaccine; alternately, the database might contain cases that were not confirmed. “I would like to emphasize that we need more research,” he said.

The human papillomavirus vaccine does not appear to increase the risk of developing Guillain-Barré syndrome, despite isolated reports of the condition following vaccination, a study shows.

“I found that there's some overlap between the incidence of Guillain-Barré in the general population and Guillain-Barré after vaccination with Gardasil,” Dr. Nizar Souayah said in an interview. However, he and his colleagues have not found Guillain-Barré to occur more often among those who have received the HPV vaccine than among people in the general population.

Dr. Souayah will be presenting the study at the American Academy of Neurology annual meeting in Seattle, April 25-May 2. The data were released early.

The Food and Drug Administration approved the vaccine in 2006 for use in girls and women aged 9–26 years to prevent infection against HPV strains 16 and 18, which cause most cervical cancers, and strains 6 and 11, which are responsible for most genital warts in the United States. Since the approval of Gardasil, more than 16 million doses have been given. There have been isolated reports of Guillain-Barré syndrome (GBS) after receiving the vaccine.

Dr. Souayah and his colleagues used data from the Vaccine Adverse Event Reporting System, which is a cooperative program for vaccine safety of the Centers for Disease Control and Prevention and the FDA. The system is a postmarketing safety surveillance program that collects information about adverse events that occur after the administration of U.S.-licensed vaccines.

Dr. Souayah searched the database using several key words: “numbness,” “tingling,” “Guillain,” “Barré,” and “Guillain-Barré syndrome.” He identified roughly 350 patients. He then reviewed the data for each of these patients and characterized them as highly likely to have GBS, highly unlikely to have GBS, and unclear. He and his colleagues included in this analysis only those patients considered to be highly likely to have GBS.

They found 36 reported cases of GBS after vaccination with the HPV vaccine in 2006–2008. The mean age was 17 years. The estimated incidence of GBS after vaccination is 7 cases per million vaccinations. In comparison, the estimated incidence for the general population is 4–10 cases per million individuals.

“The most striking data [are] that most of the Guillain-Barré syndrome cases occurred within 6 weeks of vaccination,” said Dr. Souayah, of the departments of neurology and neurosciences at the University of Medicine and Dentistry of New Jersey, Newark. The onset of GBS occurred within 6 weeks of vaccination in 75% of the individuals for whom the vaccination date was known.

“Our results show that Guillain-Barré is not occurring more often after HPV vaccination than it does in the general population. However, the fact that most of these cases occurred within 6 weeks of vaccination does warrant careful monitoring for any additional cases and continued analysis,” he said in a statement.

He urged caution in interpreting the results. The database may not contain all cases of GBS after administration of the HPV vaccine; alternately, the database might contain cases that were not confirmed. “I would like to emphasize that we need more research,” he said.

The human papillomavirus vaccine does not appear to increase the risk of developing Guillain-Barré syndrome, despite isolated reports of the condition following vaccination, a study shows.

“I found that there's some overlap between the incidence of Guillain-Barré in the general population and Guillain-Barré after vaccination with Gardasil,” Dr. Nizar Souayah said in an interview. However, he and his colleagues have not found Guillain-Barré to occur more often among those who have received the HPV vaccine than among people in the general population.

Dr. Souayah will be presenting the study at the American Academy of Neurology annual meeting in Seattle, April 25-May 2. The data were released early.

The Food and Drug Administration approved the vaccine in 2006 for use in girls and women aged 9–26 years to prevent infection against HPV strains 16 and 18, which cause most cervical cancers, and strains 6 and 11, which are responsible for most genital warts in the United States. Since the approval of Gardasil, more than 16 million doses have been given. There have been isolated reports of Guillain-Barré syndrome (GBS) after receiving the vaccine.

Dr. Souayah and his colleagues used data from the Vaccine Adverse Event Reporting System, which is a cooperative program for vaccine safety of the Centers for Disease Control and Prevention and the FDA. The system is a postmarketing safety surveillance program that collects information about adverse events that occur after the administration of U.S.-licensed vaccines.

Dr. Souayah searched the database using several key words: “numbness,” “tingling,” “Guillain,” “Barré,” and “Guillain-Barré syndrome.” He identified roughly 350 patients. He then reviewed the data for each of these patients and characterized them as highly likely to have GBS, highly unlikely to have GBS, and unclear. He and his colleagues included in this analysis only those patients considered to be highly likely to have GBS.

They found 36 reported cases of GBS after vaccination with the HPV vaccine in 2006–2008. The mean age was 17 years. The estimated incidence of GBS after vaccination is 7 cases per million vaccinations. In comparison, the estimated incidence for the general population is 4–10 cases per million individuals.

“The most striking data [are] that most of the Guillain-Barré syndrome cases occurred within 6 weeks of vaccination,” said Dr. Souayah, of the departments of neurology and neurosciences at the University of Medicine and Dentistry of New Jersey, Newark. The onset of GBS occurred within 6 weeks of vaccination in 75% of the individuals for whom the vaccination date was known.

“Our results show that Guillain-Barré is not occurring more often after HPV vaccination than it does in the general population. However, the fact that most of these cases occurred within 6 weeks of vaccination does warrant careful monitoring for any additional cases and continued analysis,” he said in a statement.

He urged caution in interpreting the results. The database may not contain all cases of GBS after administration of the HPV vaccine; alternately, the database might contain cases that were not confirmed. “I would like to emphasize that we need more research,” he said.