Vaccines and Febrile Seizures: Quantifying the Risk.

Vaccines can cause fever, and fever in young children can lead to febrile seizures; these facts are not new. Febrile seizures are the most common seizure disorder of childhood and occur in ∼5% of all children, usually those younger than 24 months. We know that vaccines, often administered to children in this age group, can trigger febrile seizures. The article by Duffy et al1 in this edition of Pediatrics provides pediatric practitioners with a fairly precise estimate of how often influenza vaccine, conjugated pneumococcal vaccine (PCV), and diphtheria-tetanus-acellular pertussis (DTaP) vaccines given alone or in various combinations lead to febrile seizures. This study, conducted by the Vaccine Safety Datalink2 (VSD), and others like it, are important as we engage in dialogue with parents about the risks and benefits of vaccines.