The U.S. Food and Drug Administration has suspended the biologics license for Valneva’s live-attenuated chikungunya vaccine, Ixchiq, with immediate effect, citing new safety data that showed more than 20 serious adverse events, 21 hospitalisations and three deaths, one of them linked to vaccine-derived encephalitis. The agency said continued use of the shot would “pose a danger to health.” Ixchiq received accelerated approval in November 2023 for adults at increased risk of infection, but confirmatory studies have yet to demonstrate a clear clinical benefit. Regulators had already paused use in older adults in May before partially lifting the restriction on 6 August. The latest suspension obliges Valneva to halt all shipments and sales in the United States while the company reviews its options. Investors reacted swiftly: Paris-listed shares of Valneva fell about 22 % and U.S.-listed receipts dropped roughly 25 % on Monday. Ixchiq generated €7.5 million in the first half of 2025, or just over 8 % of group revenue, so Valneva kept its full-year guidance unchanged. The decision leaves Bavarian Nordic’s recently approved Vimkunya as the only chikungunya vaccine available in the U.S. market.