Naturally acquired transmission-blocking immunity against different strains of Plasmodium vivax in a malaria endemic area in Thailand.

Our findings indicate that naturally acquired TBI is mainly mediated by antibodies, with possible contributions from other serum factors. The transmission-blocking activity of plasma samples varied depending on the tested parasite strain, suggesting single polymorphic or multiple targets for naturally acquired TBI. These observations improve understanding of immunity against P. vivax and hold implications for transmission-blocking vaccine development.