Febrile Seizures in Children Following Vaccination with Influenza Vaccines and Pneumococcal Vaccines — 2010-2011 Influenza Season
During the 2010-2011 influenza season, there was enhanced focus on monitoring for febrile seizures after influenza (flu) vaccine in the United States because in Australia, during the 2010 Southern Hemisphere influenza season, one type of Australian influenza vaccine was associated with an increase in febrile seizures in young children.
CDC studied the healthcare visit records of more than 200,000 vaccinated children 6 months through 4 years of age through its Vaccine Safety Datalink project during the entire 2010-2011 influenza season. The analyses found that febrile seizures following inactivated influenza and PCV13 vaccines given to this age group did occur. The febrile seizures were most common in children ages 12 through 23 months when the two vaccines were given during the same healthcare visit. In this group, about one additional febrile seizure occurred among every 2,000 to 3,000 children vaccinated. The risk observed in U.S. children was considerably lower than that obersved in Australia.
CDC, FDA, and the Advisory Committee on Immunization Practices (ACIP), reviewed vaccine safety data on febrile seizures in the United States following 2010-2011 inactivated influenza and pneumococcal conjugate (PCV 13) vaccines. After thoroughly evaluating the available information, CDC determined that no changes in the childhood immunization schedule were necessary.
Continued monitoring during the 2011-2012 influenza season detected increased febrile seizures following vaccination with inactivated influenza vaccine in young children, similar to the 2010-2011 influenza season.