Phase 2 trial to assess chikungunya vaccine candidate

Issue: December 2015

An NIH-sponsored phase 2 trial will evaluate the safety and immunogenicity of a chikungunya vaccine candidate, according to a press release.

“The recent re-emergence of chikungunya virus in this hemisphere has rapidly become a significant health burden,” Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, said in the release. “Our chikungunya vaccine development efforts are part of a broader research effort to prevent, diagnose, treat and ultimately control this painful illness, which can strike anyone unlucky enough to be bitten by an infected mosquito.”

Anthony S. Fauci

The vaccine, developed by researchers at NIAID’s Vaccine Research Center, uses virus-like particles (VLPs) instead of inactivated or weakened whole viruses. It previously demonstrated a robust immune response in 25 healthy volunteers during a phase 1 trial conducted in 2014. According to researchers, the vaccine was well-tolerated and produced high antibody levels against multiple genotypes of the virus detected in all participants 6 months after vaccination. Moreover, antibody levels were comparable to those seen in people who had recovered from a natural chikungunya infection 11 months after vaccination.

Chikungunya virus particles

Source: CDC

For the next phase, researchers will further examine the vaccine’s safety and immune responses in 400 healthy volunteers aged 18 to 60 years old at six sites in the Caribbean. Participants will be randomly assigned two doses of the vaccine candidate 28 days apart or two doses of placebo. Researchers will collect blood samples at multiple points to assess whether the vaccine produced antibodies to chikungunya virus.

Cases of chikungunya substantially increased in the Western Hemisphere since 2013, according to the release. The NIH said more than 621,000 suspected and confirmed cases have been reported in the Americas this year.