AAN: H1N1 Vaccine Association With Guillain-Barré Studied
Preliminary report estimates an occurrence rate of only 3.5 per 10 million vaccinations
WEDNESDAY, April 14 (HealthDay News) -- Few cases of Guillain-Barré syndrome were reported in patients who received the 2009 H1N1 vaccine, according to research presented at the annual meeting of the American Academy of Neurology, held from April 10 to 17 in Toronto.
Nizar Souayah, M.D., of the New Jersey Medical School in Newark, and colleagues analyzed data from the U.S. Centers for Disease Control and Prevention and the U.S. Food and Drug Administration Vaccine Adverse Event Reporting System, obtaining additional data from the center for biologics and research under the Freedom of Information Act. They excluded Guillain-Barré syndrome cases that occurred within two days of vaccination.
The researchers found that 35 cases (mean age, 36.6 years; 14 men) of Guillain-Barré syndrome were reported after 2009 H1N1 vaccination administration, resulting in an estimated occurrence rate of 3.5 per 10 million vaccinations. Among these cases, 34 were reported within six weeks of vaccination, and 23 were reported within two weeks of vaccination. In the 33 patients who were hospitalized, one patient died and another became disabled. The researchers also found that 57 cases of Guillain-Barré syndrome were reported after 2009 seasonal flu vaccination administration, resulting in an estimated occurrence rate of 7.3 per 10 million vaccinations.
"Although preliminary, these reported cases of Guillain-Barré syndrome do not appear to show an increased risk of Guillain-Barré syndrome following vaccination with either the 2009 H1N1 or the seasonal flu strain, and the safety record for these vaccines is excellent," Souayah said in a statement. "CDC, FDA and neurologists around the world are continuing to closely monitor people after vaccination for this disease."