Fig. 6

FcγR-binding efficiencies wane after RTS,S vaccination. Among children in the RTS,S vaccine group from the Manhiça study site, serum samples collected 30 days after vaccination (M3) and later time points (M8.5 and M21) were tested for various antibody responses to full-length CSP. FcγRIIa and FcγRIII binding efficiency was calculated as FcγR-binding relative to IgG magnitude for each sample at each time point. A FcγRIIa and B FcγRIII binding efficiency reduced over time (n=28, Friedman test p<0.001, respectively); C ratio of cytophilic IgG subclasses (IgG1 and IgG3) to total IgG (n=27, Friedman test p<0.001) and D ratio of cytophilic IgG subclasses to IgM (n=26, Friedman test p=0.003). Later follow-up time points were not included because the magnitude of antibodies was very low. Individual samples are shown along with the median (black lines) and 95% CI (blue lines). E Pooled samples collected at M3 (n=99) were tested at various dilutions for IgG (black line) and FcγR-binding to CSP (red line and blue line); dots and error bars represent mean and standard errors from 3 independent experiments