Seroprevalence of IgG antibodies against 13 vaccine Streptococcus pneumoniae serotypes in the Netherlands

In this study the seroprevalence of IgG antibodies against 13 vaccine serotypes of the pneumococcus was assessed in the Netherlands. Sera from 7904 persons obtained in a cross-sectional population-based study were analysed. The 13 serotype specific IgG concentrations were assessed simultaneously using a fluorescent bead-based multiplex immuno assay (MIA). Overall, the geometric mean IgG concentrations (GMCs) against the 13 serotypes in unvaccinated individuals increased with age up to 5 years and remained at a plateau thereafter. The data also show that individuals develop antibodies against an increasing number of different serotypes with increasing age. The highest GMCs were found for antibodies directed against serotype 14 and 19F, whereas antibodies against serotypes 4 and 5 had the lowest GMCs. There was no uniform relationship between the occurrence of serotypes causing invasive pneumococcal disease (IPD) and the GMCs against these serotypes. Increased IPD incidence in the elderly did not seem to be the result of a decline in the concentration of IgG antibodies.