Strategies & recent development of transmission-blocking vaccines against Plasmodium falciparum

Transmission blocking malaria vaccines are aimed to block the development and maturity of sexual stages of parasite within mosquitoes. The vaccine candidate antigens (Pfs25, Pfs48/45, Pfs230) that have shown transmission blocking immunity in model systems are in different stages of development. These antigens are immunogenic with limited genetic diversity. Pfs25 is a leading candidate and currently in phase I clinical trial. Efforts are now focused on the cost-effective production of potent antigens using safe adjuvants and optimization of vaccine delivery system that are capable of inducing strong immune responses. This review addresses the potential usefulness, development strategies, challenges, clinical trials and current status of Plasmodium falciparum sexual stage malaria vaccine candidate antigens for the development of transmission-blocking vaccines.