Stage-specific and species-specific antigens of Plasmodium vivax and Plasmodium ovale defined by monoclonal antibodies.

Monoclonal antibodies (MAbs) were produced against the asexual blood stages of Plasmodium vivax and Plasmodium ovale and used to define antigens of plasmodial parasites in an indirect fluorescent antibody assay. The anti-P. vivax MAbs produced two distinct patterns in the indirect fluorescent antibody assay. Four patterns were found with the anti-P. ovale MAbs. Species-specific epitopes were defined for P. vivax and P. ovale; epitopes shared among all four species of human malaria parasites were also defined. Some of the anti-P. vivax MAbs reacted only with mature stages, and others reacted with all asexual stages. No asexual blood-stage specificity could be found with the anti-P. ovale antibodies. Five of the anti-P. vivax MAbs and three of the anti-P. ovale MAbs also reacted with sporozoites.