PROS1 and infection: Nonetheless, the distribution of responses to protein S at T1 segregated lower and higher responders, and we observed positive correlations with age for both protein S and protein N responses in the initial time point (S, r = 0.6347, p < 0.0001; N, r = 0.3760, p = 0.0017; Spearman correlation), but not with time post-infection at T1, which shows that younger children may have lower specific responses at start.