Malaria bivalent viral vectored vaccine protects against Plasmodium falciparum and vivax and blocks parasite transmission

Abstract

Malaria remains a major infectious disease, with Plasmodium falciparum and Plasmodium vivax often co-endemic, requiring a dual-target vaccine for adequate control. We previously developed monovalent vaccines against P. falciparum or P. vivax using vaccinia virus LC16m8Δ (m8Δ) and adeno-associated virus type 1 (AAV1). Here, we demonstrate the efficacy of a novel bivalent malaria vaccine against P. falciparum and P. vivax. The m8Δ vaccine harbors two gene cassettes encoding Pfs25-PfCSP and Pvs25-PvCSP fusion proteins, while the AAV1 vaccine includes two recombinant AAV1s carrying one of these cassettes as a mixture. Heterologous m8Δ-prime and AAV1-boost immunization provided 70% protection against both PfCSP/Pb and PvCSP/Pb transgenic sporozoites. Moreover, a membrane feeding assay using P. vivax isolates from infected patients in the Brazilian Amazon showed 90% transmission-blocking efficacy. The bivalent vaccine outperformed monovalent combinations, maintaining immune responses for over 7 months, and shows promise for malaria control and elimination.