FDA Suspends U.S. License of Chikungunya Vaccine

MONDAY, Aug. 25, 2025 (HealthDay News) — The U.S. Food and Drug Administration is suspending the biologics license for the live-attenuated chikungunya vaccine, Ixchiq, in the United States. The move comes after reports of serious side effects in older adults similar to the symptoms of chikungunya virus.

Chikungunya virus is a mosquito-borne disease causing fever, rash, headache, nausea, fatigue, and severe joint and muscle pain, which can be long-lasting and debilitating.

The FDA granted accelerated approval of Ixchiq in November 2023 to prevent chikungunya virus in adults 18 years and older with an increased risk for exposure.

However, according to the FDA Vaccine Adverse Event Reporting System, Ixchiq has been linked to one confirmed encephalitis death, more than 20 serious adverse events resembling chikungunya illness, 21 hospitalizations, and three deaths in total. In addition, the FDA Center for Biologics Evaluation and Research has determined the vaccine”s clinical benefit remains unproven, its risks outweigh potential benefits in most scenarios, and continued use would endanger public health.

Valneva, the manufacturer of Ixchiq, maintains the reported cases align with known trial and postmarketing data, especially in older adults already flagged in prescribing warnings. The company is investigating further and may take additional action regarding the FDA decision.

“As we determine potential next steps, and as the clear threat of chikungunya continues to escalate globally, Valneva remains fully committed to maintaining access to our vaccine as a global health tool for addressing and preventing outbreaks of this devastating illness,” Thomas Lingelbach, the chief executive officer of Valneva, said in a statement. “We aim to continue providing Ixchiq to all countries where the product is licensed and continue our efforts with our partners to accelerate vaccine access in low-and-middle-income chikungunya-endemic countries.”

Meanwhile, Valneva will immediately stop shipping and selling the vaccine in the United States.

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