The U.S. Food and Drug Administration (FDA) has suspended the license for Valneva's chikungunya vaccine, Ixchiq, with immediate effect following reports of serious adverse events. The French drugmaker announced the suspension on August 25, 2025, citing updated data from the Vaccine Adverse Event Reporting System (VAERS) that included four new reports of serious adverse events consistent with chikungunya-like illness, some occurring outside the U.S. The FDA's decision reverses an earlier pause on the vaccine's use that was lifted in early August. The suspension was prompted by safety concerns, particularly among older patients, after previous reports of neurological injuries, heart problems, and deaths. Valneva's shares plunged approximately 20-25% following the announcement. The FDA stated that its analysis indicated the benefits of the vaccine, which contains a weakened form of the chikungunya virus, do not outweigh the risks. The suspension halts sales and distribution of Ixchiq in the U.S., marking a setback for Valneva amid ongoing chikungunya concerns.