Modeling pneumococcal nasopharyngeal acquisition as a function of anticapsular serum antibody concentrations after pneumococcal conjugate vaccine administration

•High IgG levels after PCVs have a substantial effect on nasopharyngeal carriage.•Ethnicity did not influence this association despite differences in carriage rates.•These results may have important implications for herd protection.•IgG levels higher than defined by WHO for IPD are required to prevent carriage.•IgG levels required to protect against acquisition differ between serotypes.