FDA’s CBER issues safety labeling updates for multiple flu vaccines following post-marketing data showing a small increased risk of febrile seizures.
Written By: Pharmacally Medical News Desk
The Center for Biologics Evaluation and Research (CBER) at the U.S. Food and Drug Administration has issued safety labeling change notifications on 09 January 2026 to manufacturers of several widely used influenza vaccines following new safety information about febrile seizures in young children. The updates affect products including Afluria, Flucelvax, Fluzone, Fluarix, Flulaval, and FluMist.
This action stems from an agency evaluation of post-marketing and observational data collected during the 2023-2024 and 2024-2025 influenza seasons. In these analyses, researchers found a significantly increased risk of febrile seizures within the first day after vaccination in children aged 6 months through 4 years when compared with later time periods. The increased relative risk was observed for both standard trivalent and quadrivalent influenza vaccine formulations.
Under the Federal Food, Drug, and Cosmetic Act, the FDA considers this new safety information important for healthcare providers and families. Vaccine manufacturers have been asked to submit proposed changes to product labeling that clearly reflect this risk and guide clinical use. The agency gave companies 30 days to propose these changes or explain why new labeling isn’t needed.
What the Data Shows
Post-marketing surveillance used health insurance claims data in a self-controlled case series design. This method compares the rate of febrile seizures shortly after vaccination (0 to 1 day) with a control period later after vaccination (8 to 63 days). The studies found
An approximately two-fold relative increase in febrile seizures after quadrivalent vaccine receipt in one dataset.
For standard trivalent vaccine formulations, a nearly three-fold increased rate in some analyses.
Even with these relative increases, the absolute number of excess febrile seizure events remains very low per million doses administered.
What Febrile Seizures Mean
Febrile seizures are convulsions triggered by fever. They are most common in young children and are usually brief and benign. National safety monitoring systems, including the Centers for Disease Control and Prevention (CDC), have long noted a small, elevated risk of febrile seizures after some vaccines, especially when influenza vaccine is co-administered with others like pneumococcal or DTaP vaccines.
Why the Labeling Update Matters
Accurate labeling ensures that clinicians and caregivers are aware of rare but meaningful safety signals. This supports informed decision-making, particularly for parents of young children receiving annual influenza immunization. The updated warnings and precautions will help healthcare providers counsel families on the benefits and risks of vaccination while maintaining high standards of vaccine safety monitoring.
Current Recommendations for Families
Health authorities, including the CDC and FDA, still recommend annual influenza vaccination for eligible children and adults. Febrile seizures, though concerning to families, are typically self-limited and most children recover fully. Providers should continue to follow recommended immunization schedules and discuss any specific concerns about vaccine side effects with caregivers.
If you’re a parent or caregiver of a child aged 6 months to 4 years, talk with your paediatrician about the timing of flu shots and how to monitor for fever or other reactions after vaccination.
Reference
Fluzone- Notification safety labeling change, BL 103914/7093, US FDA, 09 January 2026, https://www.fda.gov/media/190543/download?attachment
Flumist- Notification safety labeling change, BL 125020/3284, US FDA, 09 January 2026, https://www.fda.gov/media/190538/download?attachment
Fluarix- Notification safety labeling change, BL 125127/1242, US FDA, 09 January 2026, https://www.fda.gov/media/190539/download?attachment
Flulaval- Notification safety labeling change, BL 125163/751, US FDA, 09 January 2026, https://www.fda.gov/media/190540/download?attachment
Afluria- Notification safety labeling change, BL 125254/919, US FDA, 09 January 2026, https://www.fda.gov/media/190542/download?attachment
Flucelvax- Notification safety labeling change, BL 125408/675, US FDA, 09 January 2026, https://www.fda.gov/media/190541/download?attachment
Febrile Seizures and Vaccines, 20 December 2024, https://www.cdc.gov/vaccine-safety/about/febrile-seizures.html
Febrile Seizures Following Childhood Vaccinations, Including Influenza Vaccination, 17 Sept 2026, https://www.cdc.gov/flu/vaccine-safety/febrile.html
