Chikungunya vaccine shows sustained high sero-response rate one-year after single vaccination in adolescents
Vaccine company, Valneva, announced this week that its single-shot chikungunya virus (CHIKV) vaccine, IXCHIQ®, showed a sustained 98.3% sero-response rate one-year after single vaccination in adolescents (12 to 17 years old) in Phase 3 trials.
The results supported filing for potential label extension to this age group in the U.S., Europe, and Canada. Data from this trial are also expected to support licensure of IXCHIQ® in Brazil, which would be the first potential approval for use in endemic populations.
The one-year VLA1553-321 data showed that a single-dose vaccination induced a high, sustained immune response in an immunogenicity subset of participants who were CHIKV negative at baseline, with a seroresponse rate of 98.3% (232 out of 236 participants) one year after vaccination (Day 360) compared to 99.1% (232 out of 234 participants) after six month (Day 180) and 98.8% (248 out of 251 participants) 28 days, after vaccination. The results complement the long-term persistence data previously reported for adults, confirming a strong and long-lasting antibody response to the vaccine.
Additionally, the one-year data confirmed that a single dose of the vaccine was generally well tolerated in adolescents. Throughout the trial, an Independent Data Safety Monitoring Board (IDSMB) consistently assessed safety data and found no safety issues.
VLA1553-321 is a prospective, double-blinded, multicenter, randomized, placebo-controlled pivotal Phase 3 trial conducted in 754 adolescents aged 12 to 17 years old in Brazil. The VLA1553-321 clinical trial was initiated in January 2022 and Valneva reported immunogenicity and safety data 28 days and six months after a single vaccination in 2023 and 2024, respectively.
Chikungunya virus (CHIKV) is a mosquito-borne viral disease spread by the bites of infected Aedes mosquitoes which causes fever, severe joint and muscle pain, headache, nausea, fatigue and rash. Joint pain is often debilitating and can persist for weeks to years.