Extended Data Fig. 3: Exploring synergistic effects of anti-SLO, -SpyAD and -SpyCEP IgG with protection from culture confirmed events.

(a) IgG levels (above the transition point of 4.3 log10 RLU ml−1 for SLO, 4.1 log10 RLU ml−1 for SpyAD and 4.3 log10 RLU ml−1 for SpyCEP) were included in all possible combinations with and without interaction terms and including covariates known to alter risk of S. pyogenes events: age group, sex and household size. AIC value for each model is plotted +− 2 represented by dotted lines. This allowed the selection of the model including IgG levels to SLO, SpyAD and SpyCEP without interaction terms (in bold text) to be used to explore synergistic effects between antigens. (b) Forest plot to visualise the association between IgG level above transition point for each conserved antigen and any culture-confirmed event within 45 days (n = 4677 visits with 1987 antibody measurements). Odds ratios (points) were calculated from a mixed effects logistic regression model adjusting for factors known to alter risk of S. pyogenes events: age, sex and household size. Horizontal bars represent 95% Wald confidence intervals. AIC = Akaike information criterion.