Long term HAART cohorts (group A, n=29 and group B, n=10) were immunized with PPV23. Serum samples were obtained on day 0 (pre-vaccination, white bars) and day 30 (post-vaccination, black bars) and tested for PPS14- and PPS23F-specific IgG (A, B), IgM (C, D), and opsonophagocytic activity (E, F). Serum antibody levels are expressed as μg/ml, and opsonophagocytic activity is expressed as opsonophagocytic titer (OPT). Pre to post vaccination changes in response were compared using analysis of co-variance (ANCOVA). Data are represented as mean ± standard errors of the mean (SEM). *p<0.05, **p<0.01, ***p<0.001.
