The US Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) have jointly recommended a pause in the use of Valneva’s single-dose chikungunya vaccine, IXCHIQ, for individuals aged 65 and older. This precautionary measure follows reports of serious adverse events (SAEs) in elderly individuals with underlying medical conditions, including one fatality, during the ongoing vaccination campaign in La Réunion, France. These cases were reported through the Vaccine Adverse Event Reporting System (VAERS), though a causal relationship with the vaccine has not been established.
What You Need To Know
FDA and CDC recommend pausing IXCHIQ® use in adults aged 65 and older due to reports of serious adverse events, including one fatality, though no confirmed causal link to the vaccine has been established.
IXCHIQ remains authorized for use in individuals aged 18 to 60 in the U.S. and 12 to 64 in Europe, with continued use in La Réunion amid an active outbreak.
ACIP’s earlier safety review of Valneva’s vaccine identified concerns in older adults with comorbidities, contributing to the current regulatory action and ongoing investigation into reported adverse events.
To date, over 40,000 doses of IXCHIQ® have been administered worldwide. The vaccine remains authorized for use in individuals aged 18 to 60 in the U.S. and for those aged 12 to 64 in Europe. In France, the national public health agency, Haute Autorité de Santé (HAS), continues to recommend vaccination for individuals aged 18 to 64 in La Réunion, where a significant chikungunya outbreak is ongoing.
Valneva is collaborating with health authorities to investigate these SAEs and has committed to providing timely information about all known adverse events. The company maintains that the benefits of IXCHIQ outweigh the risks for the majority of individuals aged 18 to 60. Further updates will be provided as evaluations are concluded.
Chikungunya virus is a mosquito-borne disease that causes fever, severe joint and muscle pain, headache, nausea, fatigue, and rash. Joint pain can be debilitating and may persist for weeks to years. Since its re-emergence in 2004, chikungunya has been identified in over 110 countries, with more than 3.7 million cases reported in the Americas between 2013 and 2023. The World Health Organization has highlighted chikungunya as a major public health problem.
At its April 16, 2025, meeting, the Advisory Committee on Immunization Practices (ACIP) recommended the virus-like particle chikungunya vaccine for travelers aged 12 and older visiting outbreak or high-risk areas, as well as for laboratory workers with potential occupational exposure. The committee also recommended the live attenuated vaccine for individuals aged 18 and younger traveling to outbreak regions. During the meeting, ACIP reviewed safety data for Valneva’s live attenuated vaccine IXCHIQ, identifying six SAEs and noting the difficulty of assessing vaccine-related reactions in older adults with comorbidities.2 These concerns reflect this formal update on May 12, when the FDA and CDC jointly recommended pausing the use of IXCHIQ in people aged 65 and older. The timeline reflects a progression from early safety review to regulatory action.
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