Valneva’s VLA1553 (Ixchiq) vaccine was shown to met its preliminary endpoint, with 98.9% of participants reaching protective levels of chikungunya virus neutralizing antibodies 1 month after vaccination.
The FDA announced tonight that it had approved Valneva’s VLA1553 (Ixchiq) vaccine for the prevention of the Chikungunya Virus. This is the first approved vaccine for this vector-borne disease, which is endemic in tropical and subtropical regions of Africa, Southeast Asia, and parts of the Americas where chikungunya virus-carrying mosquitos live.
“Infection with chikungunya virus can lead to severe disease and prolonged health problems, particularly for older adults and individuals with underlying medical conditions,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research. “Today’s approval addresses an unmet medical need and is an important advancement in the prevention of a potentially debilitating disease with limited treatment options.”
What the Data Demonstrated
The phase 3 clinical trial, VLA1553-301, included 4115 adults 18 years and older. The prospective, double-blind, multicenter, randomized trial commenced in September 2020. Participants received a single dose of lyophilized VLA1553 or placebo, administered as an intramuscular injection.
VLA1553 was also found to be highly immunogenic in study participants 65 years and older, who demonstrated high seroprotection and neutralizing antibody titers comparable to younger participants. Valneva confirmed they will continue monitoring a subset of participants for at least 5 years after VLA1553 vaccination to verify the expected long-term protection of a single injection.
Ixchiq is administered as a single dose by injection into the muscle. It contains a live, weakened version of the chikungunya virus and may cause symptoms in the vaccine recipient similar to those experienced by people who have chikungunya disease.
The most commonly reported side effects by vaccine recipients were headache, fatigue, muscle pain, joint pain, fever, nausea and tenderness at the injection site.
The FDA is requiring the company to conduct a postmarketing study to assess the serious risk of severe chikungunya-like adverse reactions following administration of Ixchiq.
Transmission of chikungunya virus to newborn babies from pregnant individuals with viremia (virus present in the blood) at delivery has been reported and can cause severe, potentially fatal chikungunya virus disease in newborns.
FDA Approves First Vaccine to Prevent Disease Caused by Chikungunya Virus. FDA press release. November 9 2023.