FDA Requests Flu Vaccine Label Updates for Febrile Seizure Risk in Young Children
On January 9, 2026, the FDA notified flu vaccine manufacturers of new safety information requiring label updates to warn of increased febrile seizure risk in children 6 months through 4 years old.1
Studies from 2023-2024 and 2024-2025 flu seasons using self-controlled case series analyses showed significantly elevated risk on day 0-1 post-vaccination compared to days 8-63.1
For quadrivalent (2023-2024) vaccine, IRR was 1.97 (95% CI: 1.09-3.54), with 21.2 excess episodes per million doses; for trivalent (2024-2025), IRR was 2.94 (95% CI:
1.72-5.01), with 44.2 excess episodes per million doses.1
Manufacturers must submit labeling supplements within 30 days, adding warnings under sections 5.x and 6.2.1