FIG 3.

Binding of P*17/K4S2(DT) antisera to S. pyogenes. The binding of anti-P*17/K4S2(DT) and naive sera were assessed against heat-killed pM1 (HKpM1; covR/S WT) and heat-killed 5448AP (HK5448AP; covR/S MT) using whole-cell ELISA. Vaccine antibodies specific for HKpM1 and HK5448AP were detected using HRP-conjugated mouse secondary IgG antibody. The endpoint titer was defined as the highest dilution that gave an absorbance of >3 standard deviations above the mean absorbance of negative control wells. Data for 5 mice (± SEM) in vaccinated and control cohort are shown. Statistical analysis was performed using a nonparametric, unpaired Mann-Whitney U test (one-tailed) to compare naive antisera with P*17/K4S2(DT) antisera (**, P < 0.01). Statistical analysis and graphs were generated in GraphPad Prism 8.1.2.