Figure 3

Anti-S IgG positivity rate of individual HCoVs according to age group. (A) Anti-S IgG positivity rates for HCoV-229E; (B) Anti-S IgG positivity rates for HCoV-OC43; (C) Anti-S IgG positivity rates for HCoV-HKU1; (D) Anti-S IgG positivity rates for HCoV-NL63.