No changes on viral load and CD4+ T-cell counts following immunization with 7-valent pneumococcal conjugate vaccine among HIV-infected adults in Malawi.

Vaccination has been associated with a transient increase in viremia in HIV-infected individuals, although contradicting evidence persist in the literature. As part of a randomized placebo-controlled efficacy trial of the PCV7 in Malawi, we collected viral load and CD4+ T-cell counts from 237 adults who received two doses of vaccine or placebo, administered 4 weeks apart. Analyses were conducted separately for cART and non-cART users. Our analysis show no difference in viral loads between vaccine and placebo groups, regardless of cART use. Viremia decreased from 4.1 to 2.9 log copies/mL (p < 0.0001) among those using cART, consistent vaccine and placebo groups, but no changes were seen among the non-cART cohort. CD4+ T-cell counts remained unchanged regardless of cART use, or allocation to vaccine or placebo. We concluded that there was no evidence of detrimental effects of PCV7 administration on viral load or CD4+ T-cell counts six months after vaccination with PCV7.