Hierarchy of immunogenicity of Plasmodium falciparum merozoite antigens and vaccine candidates in first human infection

In 81 malaria-naive adults undergoing blood-stage Plasmodium falciparum CHMI, IgG and IgM to whole merozoites were detectable by two weeks, with IgG showing a strong antigen immunogenicity hierarchy.

• Why it matters: Antigen-by-antigen immunogenicity after first infection is unclear, limiting rational selection of vaccine targets and the design of malaria serosurveillance assays.
• What they did: IgG and IgM responses to whole merozoites and individual merozoite antigens were measured after CHMI in 81 malaria-naive adults, revealing early acquisition and distinct immune-acquisition clustering.
• The result: IgM was acquired to most antigens with a broader, less hierarchical profile, and participants formed distinct antibody breadth/magnitude groups, suggesting individual variation begins with first exposure.