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# FDA Extends Review of Chikungunya Vaccine
- URL: https://www.fdaweb.com/fda-extends-review-of-chikungunya-vaccine/
- Published: 2023-08-14T12:00:00.000Z
- Updated: 2026-09-14T18:50:24.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5155088

FDA has extended by three months the review of a Valneva BLA for VLA1553, the company’s chikungunya virus vaccine candidate to allow “sufficient time to align and agree on the Phase 4 program necessary under the accelerated approval pathway,” according to the company. No additional clinical data have been requested at this time, it says. A review action is now expected by the end of November.

Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus transmitted by *Aedes* mosquitoes. It causes rapid large outbreaks with high attack rates, affecting up to three-quarters of the population in areas where the virus is circulating, according to the company.

Data from the company’s Phase 3 trial was recently published in [*The Lancet*](https://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2823%2900641-4/fulltext?ref=fdaweb.com)*. Data showed* that the vaccine demonstrated a “very high seroresponse rate of 98.9% in participants 28 days after receiving the single administration,” the company says. “This immunogenicity profile was similar in both younger and older adults, and 96% of participants maintained seroresponse six months after vaccination. VLA1553 was generally safe and equally well tolerated in younger and older adults.”