Immunogenicity of 23-valent pneumococcal polysaccharide vaccine in children with human immunodeficiency virus undergoing highly active antiretroviral therapy.

BACKGROUND: The 23-valent pneumococcal polysaccharide vaccine (23PSV) has been recommended for children infected with human immunodeficiency virus (HIV); however, the efficacy of this vaccination in HIV-infected children undergoing highly active antiretroviral therapy (HAART) has not been studied.
OBJECTIVE: To study the immunogenicity and immunologic protection of 23PSV in HIV-infected children after stable HAART.
METHODS: Serotype-specific IgG antibodies to 12 pneumococcal capsular polysaccharides were analyzed before and after 23PSV vaccination in 41 HIV-infected children undergoing HAART and compared with 95 HIV-negative control children. Seropositivity, clinical protection, and additional clinical protection from 23PSV were calculated based on serotype specific IgG antibody levels and on the known incidence of these serotypes for causing invasive disease.
RESULTS: Children with HIV infection undergoing HAART developed a significant increase in specific IgG levels to Streptococcus pneumoniae after 23PSV vaccination (0.95 vs 1.84 micro/gmL, P < .001). The HIV-infected children with CD4+ cell counts of 25% or higher at the time of vaccination developed a higher additional clinical protection gain from 23PSV vaccination than did children with a lower percentage of CD4+ cells.
CONCLUSIONS: HIV-infected children undergoing stable HAART develop a significant immunologic response to 23PSV, especially those with higher T-cell counts and lower viral loads at the time of vaccination.