Valneva voluntarily withdrew its U.S. chikungunya vaccine application after the FDA placed a clinical hold linked to a newly reported serious adverse event outside the U.S. The company said the event occurred in a recipient who received three vaccines concurrently and that causality has not been established. Ixchiq had received accelerated approval in 2023 but faced safety scrutiny across regulators, including EMA actions and an FDA suspension last year. Valneva plans to continue post‑marketing activities pending regulatory dialogue but has removed its U.S. filing and halted the associated post‑marketing study.