Vaccine-associated febrile seizures do not increase risk for developmental problems

Children who experienced febrile seizures after vaccination were not at an increased risk for developmental or behavioral problems, according to researchers.

“While febrile seizures are the most common form of childhood seizure, affecting 3% to 5% of children under the age of 6, vaccine-associated febrile seizures are rare,” Lucy Deng, MBBS, DCH, MIPH, FRACP, a staff specialist/clinical lecturer at the National Centre for Immunisation Research and Surveillance (NCIRS) in Sydney, Australia, told Healio Primary Care. “Only 6% of all first febrile seizures in children under 6 years old were vaccine-proximate and they are most commonly associated with a measle-containing vaccine.”

Deng and colleagues conducted a prospective cohort study at four tertiary pediatric hospitals in Australia.

They compared developmental and behavioral outcomes in 62 children aged younger than 30 months who experienced vaccine-associated febrile seizures with vaccination with outcomes in 70 children who had febrile seizures that were not associated with vaccination and 90 children of similar in age who did not experience a seizure.

Researchers assessed children’s development using the Bayley Scales of Infant and Toddler Development, Third Edition, which was administered to participants 1 to 2 years after their first febrile seizure, and in controls at age 12 months to 42 months. They also evaluated participants’ preacademic skills and used parent questionnaires to obtain information on their behavior and executive functioning.

The results of the study were published in Neurology, the medical journal of the American Academy of Neurology.

Deng and colleagues determined that there were no significant differences between the groups in their cognitive, language, motor, social-emotional or general adaptive function scores.

They also found that there was no significant difference in preacademic skill, executive function, or in emotional or behavioral problems between all three groups.

“Showing that a febrile seizure following vaccination does not significantly affect developmental and behavioral outcomes in young children provides reassurance to clinicians and parents on the neurodevelopmental outcome of a well-known adverse event following immunization,” Deng said. “This information will aid clinicians counseling parents on the longer effects of a rare but serious adverse event following immunization.”

She noted that a follow-up study of the cohort in late childhood would “add to the longitudinal data on developmental and behavioral outcomes.”

References:

Deng L, et al. Neurology. 2020;doi:10.1212/WNL.0000000000009876.

Deng L, et al. Pediatrics. 2019;doi: 10.1542/peds.2018-2120.