Cross-reactivity of human AMA1 antibodies in PNG children versus adults. Each graph (A-E) shows cross-reactivity of one specific AMA1 allele. The top part of each graph shows data from a cohort of adults in PNG and the bottom part shows data from a cohort of children in PNG. Each variant (A-E) was competed in competition ELISA against four other AMA1 alleles and cross-reactivity was determined. For each graph the color-filled bars in the top and in the bottom part show cross-reactivity between the indicated allele and the variant tested. Cross-reactivity of naturally acquired antibodies in children was slightly lower for all alleles when compared to adults (P = 0.002); however, the pattern of cross-reactivity for each allele was similar among children and adults. Data on antibody cross-reactivity for children were extracted from the same dataset as shown in Figure 1. For each figure (A-E), the competing antigens used are those listed on the Y-axis. AMA1, apical membrane antigen 1; PNG, Papua New Guinea.