NANP and parasitic infectious disease: Through the cloning, functional, and structural analysis of prevalent IgG anti-NANP antibodies, we demonstrated how the R21-generated plasma antibody, MA6, inhibits sporozoite cell invasion in cell culture, curtails parasitemia, protects in a transgenic mouse model, and mediates NANP recognition through a canonical CDR-H2 Trp52 structural motif encoded by IGHV3-33.