According to the vaccine's maker, Valneva, the FDA based its decision to suspend the shot on four new serious adverse events that happened outside the U.S., three of which were in people ages 70 to 82 years and the other in a 55-year-old individual.

By Stephanie Brown HealthDay ReporterMONDAY, 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.

Less than three weeks after lifting a pause on the use of Valneva’s chikungunya vaccine Ixchiq, the FDA has done an about-face, banning the use of the shot in the United States. | Less than three weeks after lifting a pause on the use of Valneva’s chikungunya vaccine Ixchiq,