Persistence of antibody to 23-valent pneumococcal polysaccharide vaccine: a 5-year prospective follow-up cohort study

ABSTRACTBackground Pneumococcal vaccines are effective in preventing pneumococcal diseases in adults. The evaluation of the antibodies persistence to the 23-valent pneumococcal polysaccharide vaccine (PPV23) could provide evidence on PPV23 revaccination.Research design and methods Adults aged ≥ 60 years were selected and vaccinated with PPV23 in Shanghai, and followed up for 5 years with blood samples collection of a 1-year interval. The geometric mean concentrations (GMC) of the IgG against 23 pneumococcal serotypes covered by PPV23 were detected using enzyme-linked immunosorbent assay. The antibodies to 23 pneumococcal serotypes among different groups was analyzed using statistical analysis.Results Overall, 517 participants completed all six visits over a 5-year period (2013–2018). The GMC of 23 serotypes in adults aged ≥ 60 years decreased slowly after PPV23 vaccination compared to baseline pre-vaccination (P