Plasmodium vivax VIR Proteins Are Targets of Naturally-Acquired Antibody and T Cell Immune Responses to Malaria in Pregnant Women
Human IgG antibodies against VIR proteins and peptides were detected by Luminex in peripheral blood at different timepoints: A) recruitment (first antenatal visit) (top panel), B) delivery (middle panel) and C) postpartum (after puerperium) (lower panel). Antibody levels are represented as median fluorescence intensity (MFI). Reactivity (MFI) against GST was subtracted from MFI values obtained against individual recombinant proteins. Median (white line), and 25th and 75th percentiles (lower and upper hinge respectively) are represented as boxes. Outside values are not displayed in the graph. Numbers below boxes represent percentage of positive responses, calculated as number of plasmas samples with MFI values above the mean plus 3 standard deviations of negative controls (cutoff). Cutoff for India samples was calculated with negative samples analyzed at this site and therefore differed from those used for the other sites. p corresponds to one-way ANOVA plus Bonferroni pairwise correction. Differences only displayed versus PNG. *p<0.05, **p<0.01, ***p<0.001 (adjusted p-values multiple comparisons). Sample size for each country, timepoint and antibody is provided in S4 Table. BR: Brazil; CO: Colombia; GT: Guatemala; IN: India; PNG: Papua New Guinea.