Objective: To compare the safety and immunogenicity of a 5-valent pneumococcal conjugate vaccine to a licensed 23-valent polysaccharide pneumococcal vaccine in HIV-infected and non-HIV-infected children > or = 2 years old.
Methods: Thirty HIV-infected and 30 non-HIV-infected children > or = 2 years old were randomized to receive either a 5-valent pneumococcal conjugate vaccine (PCV) or a 23-valent pneumococcal polysaccharide vaccine (PPV) intramuscularly. Children who received PCV initially were given PPV after 6 weeks. Sera were obtained before and at 6 and 12 weeks after the first vaccination to determine IgG pneumococcal antibody titers by enzyme-linked immunosorbent assay to the 5 serotypes represented in the PCV.
Results: Both vaccines were well-tolerated with no significant differences in the rates of fever (0 to 14%) or local reactions (0 to 40%) noted between PCV and PPV recipients. Pre-first vaccination geometric mean antibody titers (combined PCV and PPV recipients) to 3 of the 5 pneumococcal types tested were significantly lower in HIV-infected than in non-HIV-infected children (in microgram/ml: type 6B, 0.179 vs. 0.565; type 14, 0.026 vs. 0.060; type 23F, 0.025 vs. 0.119, respectively; P < 0.05). Fewer > or = 4-fold titer rises were observed in HIV vs. non-HIV-infected children whether they received PCV initially (60% vs. 79%, P < 0.05) or PPV (31% vs. 59%, P < 0.05). Also PCV elicited more > or = 4-fold titer rises compared with PPV in HIV-infected (60% vs. 31%, P < 0.05) and non-HIV-infected (79% vs. 59%, P < 0.05) children. No consistent antibody-boosting effect was noted in subjects who received PPV after PCV.
Conclusions: We conclude that antibody responses to natural infection, PCV and particularly PPV are poorer in HIV-infected than in non-HIV-infected children. PCV is as safe as and more immunogenic than the currently licensed PPV among HIV-infected and non-HIV-infected children.