Pneumococcal responses are similar in Papua New Guinean children aged 3-5 years vaccinated in infancy with pneumococcal polysaccharide vaccine with or without prior pneumococcal conjugate vaccine, or without pneumococcal vaccination
Fig 2
Pneumococcal serotype-specific IgG antibody titers before and after challenge.
Serum antibody titers were assessed in 3-5-year-old children who had received PCV7 and PPV23 as infants (white bars; n = 100 /n = 86), who had received only PPV23 as infants (grey bars; n = 32 /n = 28), or who had not received pneumococcal vaccines (striped bars; n = 121 pre-challenge/ n = 98 post-challenge) (A) before and (B) after challenge with a low dose of PPV23. Data are presented as geometric mean titers and 95% confidence intervals. Serotype-specific geometric mean titers before or after challenge were compared between each group using Mann-Whitney U test. * p < 0.05.