Risk of Febrile Seizures After Vaccines Quantified In New Analysis

Scientists know that vaccines sometimes cause fever, and can infrequently lead to febrile seizures among young children. A study in the July 2016 Pediatrics helps quantify how often febrile seizures occur, and finds that the risk is small. The study draws from data provided through the Vaccine Safety Datalink, a collaborative project between the Centers for Disease Control and Prevention and health care organizations. The study, “Febrile Seizure Risk Following Vaccination in Children 6-23 Months” (published online June 6) reviewed data on frequency of febrile seizures between 2006 through 2011. The study found that the risk of febrile seizures increased with the simultaneous administration of the Pneumococcal conjugate vaccine (PCV) with influenza vaccine or a vaccine to prevent diphtheria, tetanus, and whooping cough (DTaP). The study found that the vaccines can lead to febrile seizures at a rate of up to 30 per 100,000 children immunized. According to a commentary that accompanies the study, this would translate into approximately one additional febrile seizure per pediatric practice every five to 10 years. The commentary, “Vaccines and Febrile Seizures: Quantifying the Risk,” was written by three leaders of the AAP Committee on Infectious Diseases who reviewed the study. Authors of both reports concluded that the benefits of the vaccines far outweigh the risks of febrile seizures, which rarely have long-term effects. Withholding or delaying immunization could potentially lead to even more febrile seizures associated with the diseases.