Progress Toward the Development of a Plasmodium Vivax Malaria Vaccine

It is currently estimated that a total of 2.6 billion people live at a permanent risk of suffering malaria infection worldwide, and that 80-300 million experience Plasmodium vivax infections every year mostly in areas outside Africa. The increasing P. vivax drug resistance and recent reports of severe and lethal cases, the relapsing parasite behavior and the existence of Plasmodium spp. co-infections must prompt more investment and greater efforts for the development of a P. vivax vaccine. Because of funding shortage and technical difficulties, currently there are only two P. vivax vaccine candidates being tested in clinical trials and few others are being assessed in preclinical studies which contrast with the numerous P. falciparum vaccine candidates under evaluation. However, the recent availability of the P. vivax genome and ongoing proteomic analysis are likely to accelerate P. vivax vaccine development. Additionally, recent development of human sporozoite-challenge models would contribute to move clinical development forward and to identify mechanisms of immunity.