Safety and Tolerability of a Chikungunya Virus–Like Particle Vaccine in Endemic Regions

Over the past 15 years, chikungunya infections have achieved wider geographic distribution, causing large outbreaks at times. A chikungunya virus–like particle (CHIKV VLP) was found safe and immunogenic in a phase 1 trial performed in a nonendemic region. In this phase 2 trial, investigators assessed CHIKV VLP's safety, tolerability, and immunogenicity in an endemic region in a multicenter, randomized, placebo-controlled study.

Some 400 chikungunya-seronegative adults were randomized to receive two doses of either 20-mg CHIKV VLP or placebo. Injection-site reactions were mild to moderate and more likely to occur in the vaccine group (31% vs. 19%). There were 16 adverse events reported, 75% of which occurred in the vaccine group, and all reso…