On Aug. 25, the FDA informed the public that the agency officially suspended its approval for Valneva’s Ixchiq vaccine.

Ixchiq is a vaccine for Chikungunya, a mosquito-borne disease. The vaccine was initially approved to be administered in the United States in November 2023, under the FDA’s fast-tracked accelerated approval pathway.

Let’s go through what the data showed, as well as why the FDA decided this move to stop the vaccine was necessary.