Plasmodium vivax 25 kDa ookinete surface antigen (Pvs25)

Plasmodium vivax 25 kDa ookinete surface antigen (Pvs25) is a prominent surface protein expressed during the sexual stages of the Plasmodium vivax parasite, specifically on the surface of zygotes and ookinetes within the mosquito midgut. It contains four epidermal growth factor (EGF)-like domains and is essential for the parasite's transition from the mosquito midgut to the oocyst stage, making it a primary candidate for transmission-blocking vaccines (TBVs). Unlike pre-erythrocytic or blood-stage targets, Pvs25 does not protect the individual from infection but rather prevents the spread of malaria within a population by inducing antibodies in the human host. When a mosquito bites a vaccinated individual, it ingests these antibodies along with the parasite; the antibodies then bind to Pvs25, neutralizing the ookinetes and preventing further development. Clinical development has focused on various platforms, including recombinant proteins and virus-like particles (VLPs), though achieving sustained high antibody titers remains a significant challenge. Research continues to optimize adjuvant formulations to overcome reactogenicity while maintaining the robust immune response necessary for effective transmission blocking.

Other names

Pvs25 surface protein25 kDa ookinete surface proteinP25Ookinete surface protein P25

Induction of transmission-blocking antibodies (TBA) that inhibit the development of the parasite within the mosquito midgut after ingestion of an infectious blood meal.