This is a Phase 2 parallel-group age- and gender-matched open-label study in 60 healthy adults 18-65 years of age to assess the safety and immunogenicity of an alum-adjuvanted chikungunya virus-like particle vaccine (PXVX0317) in prior recipients of other alphavirus vaccines versus alphavirus naïve controls.

It is currently unknown whether prior exposure to heterologous alphaviruses will enhance or interfere with immune responses to chikungunya virus (CHIKV) exposure or vaccination.

The objective of this study is to evaluate the safety and immunogenicity of the chikungunya vaccine candidate PXVX0317 when administered to prior recipients of experimental alphavirus vaccines versus alphavirus naïve gender and age-matched controls.