Valneva voluntarily withdrew its chikungunya vaccine’s U.S. filings after learning the FDA placed a clinical hold tied to a newly reported serious adverse event outside the U.S. The company previously faced regulatory scrutiny, including an August U.S. suspension and an EMA temporary restriction after reports of severe events and hospitalizations. Ixchiq had received accelerated approval in November 2023 and was the first U.S. vaccine cleared for chikungunya. Valneva said it will continue post‑marketing clinical activities in consultation with regulators but has removed its U.S. applications pending further investigation. The move highlights intensified post‑market safety oversight for recently approved vaccines and raises questions about commercial prospects in the U.S. market for Ixchiq.