Single dose rVSVΔG-JUNVGP vaccine protects guinea pigs against lethal Junin virus challenge

Junin virus (JUNV) is a pathogen of biodefense importance due to its potential for aerosol transmission and mortality rates reaching 30%. Currently, there are no JUNV vaccines licensed by the United States Food and Drug Administration (FDA) for at-risk individuals. A vaccine based on recombinant vesicular stomatitis virus (rVSV) has been effectively used to prevent Ebola virus disease in humans. Here, we evaluated the protective efficacy of a rVSV expressing the JUNV glycoprotein (rVSV Delta G-JUNVGP) in a guinea pig model of lethal JUNV disease. Two groups of guinea pigs, one prime and one prime-boost, were vaccinated with rVSV Delta G-JUNVGP; six control animals remained unvaccinated. Survival for prime and prime-boost vaccinated animals was 100% while the challenge virus was uniformly lethal in all control animals. Animals in both vaccine groups developed robust, high avidity IgG antibody titers post-vaccination as well as detectable neutralizing antibodies while control animals failed to develop detectable antibody responses. This study demonstrates for the first time that rVSV expressing the JUNV GP fully protects guinea pigs from lethal JUNV challenge with a single injection vaccine.

Automated summary

The rVSV Delta G-JUNVGP vaccine showed excellent protective efficacy against JUNV virus in guinea pig models, with a 100% survival rate in vaccinated animals and robust antibody responses. This study represents the first demonstration of the vaccine's efficacy in providing full protection against lethal JUNV challenge with a single injection.