French drugmaker Valneva’s shares dropped over 20% after the US Food and Drug Administration (FDA) suspended the licence for its chikungunya vaccine Ixchiq due to serious safety concerns. The regulator cited reports of more than 20 hospitalizations, three deaths, including one fatality linked to vaccine-derived encephalitis.
Ixchiq received accelerated approval in November 2023 for adults at high risk of chikungunya but confirmatory trials have yet to show clear clinical benefits. The FDA’s Centre for Biologics Evaluation and Research (CBER) stated that the vaccine’s benefits do not outweigh its risks, posing a danger to health.
Valneva will halt shipping and sales of Ixchiq in the US and is evaluating permanent withdrawal from the market. However, the company maintains its financial outlook. The suspension leaves Bavarian Nordic’s Vimkunya as the sole remaining chikungunya vaccine available in the US. Despite this, some analysts see the setback as an attractive entry point for investors.
Chikungunya, spread by Aedes mosquito species, can cause severe symptoms including high fever, joint pain, and long-term disability. Ixchiq uses a weakened virus to stimulate an immune response, similar to its European approval.
Source: https://www.reuters.com/business/healthcare-pharmaceuticals/valneva-shares-tumble-after-suspension-us-chikungunya-vaccine-licence-2025-08-25