FDA Suspends BLA for Chikungunya Vaccine

The Food and Drug Administration suspended the biologics license application (BLA) for Valneva’s live-attenuated chikungunya virus vaccine (Ixchiq) on Monday following reports of safety concerns among vaccine recipients. According to the agency, there have been more than 20 serious adverse events (SAEs) reported, including one fatality from encephalitis directly attributable to the vaccine. FDA also noted that the clinical benefit of the vaccine, approved in 2023 under the agency’s accelerated approval pathway, has not yet been verified in confirmatory clinical studies.

Earlier this year, FDA paused use of the Ixchiq in individuals over the age of 60 while the agency investigated postmarketing reports of SAEs; the pause was lifted after FDA approved required labeling updates.

A second chikungunya vaccine (Vimkunya, Bavarian Nordic), which received FDA approval in February, is a recombinant vaccine based on a virus-like particle platform and does not contain live virus. It remains available for travelers at risk of CHIKV exposure.