Immunogenicity and protection-inducing ability of recombinantPlasmodium vivaxrhoptry-associated protein 2 inAotusmonkeys: A potential vaccine candidate

Rhoptry proteins have been extensively shown to be important in invasion and parasitophorous vacuole (PV) formation. This work evaluates the immunogenicity and protective efficacy ofPlasmodium vivaxRAP2 in the non-humanAotusprimate model, when expressed as a recombinant molecule inE. coliand formulated in Freund and Alum hydroxide adjuvants. Our results show that rPvRAP2 is immunogenic in both formulations, finding a trend of higher cytokine levels in immunized monkeys, specially in IL-4 levels (using Freund's adjuvant) and IL-5 (using Alum hydroxide). RAP2 is suggested as aP. vivax-vaccine candidate since immunized monkeys exhibited lower parasitemias than control groups after being experimentally challenged with theP. vivaxVCG-I strain.