USF Health Discovers New Malaria Vaccine Target

Researchers at the University of South Florida (USF) Health have made a significant breakthrough in malaria research by identifying a new vulnerability in the Plasmodium vivax malaria parasite. This discovery could pave the way for the development of a new vaccine targeting this widespread parasite, responsible for millions of infections in Central and South America and Southeast Asia. The findings, published in the journal Immunity, reveal a specific site on the parasite's circumsporozoite protein (CSP) that antibodies can target to prevent the parasite from invading liver cells. This could potentially block the establishment of dormant forms that cause relapses. This research highlights a previously uncharacterized epitope on the CSP, which has not been targeted by researchers in over 40 years. Noah Sather, PhD, a professor in the College of Public Health’s Department of Global, Environmental and Genomic Health Sciences, emphasized the importance of this discovery, referring to it as a game-changing development in malaria vaccine research.

Sather and his colleague John Adams, PhD, discovered that antibodies directed at this newly identified site can effectively inhibit P. vivax from infecting liver cells, thus preventing the formation of dormant forms that can reactivate and cause malaria relapses. The research team noted that approximately three-quarters of P. vivax transmissions arise from relapse infections rather than initial mosquito bites. By focusing on preventing the establishment of these dormant forms, the new vaccine could significantly reduce both disease transmission and the incidence of malaria. The identification of this target offers a new avenue for vaccine development, providing researchers with a specific site to focus their efforts on creating effective immunizations against P. vivax.

The discovery was the result of collaboration between two research teams that approached the problem from different scientific angles. Sather and Adams independently identified the same vulnerable region of the parasite and later joined forces to validate their findings. This convergence of evidence from both human studies and vaccine development experiments bolstered their confidence in the significance of this new target. Their combined expertise allowed them to construct a comprehensive understanding of the parasite’s vulnerabilities, likening their discovery to finding the Achilles’ heel of P. vivax. While this discovery represents a significant step forward in malaria research, Sather and Adams caution that the journey to eradicating malaria is still long. The presence of another malaria parasite, Plasmodium falciparum, which is responsible for most severe cases in sub-Saharan Africa, continues to pose challenges. However, the identification of this new target on P. vivax opens up promising possibilities for future vaccine development, potentially leading to more effective prevention strategies against malaria and its relapses.