RESUMO
The objective of this study was to estimate the protective effect of Bacille Calmette-Guérin (BCG) vaccine against tuberculosis among (predominantly immunodeficient) HIV-infected children in Angola. A hospital-based case-control study was conducted with 230 cases, children coinfected with tuberculosis, and 672 controls, HIV-infected children from the same hospital, aged 18 months to 13 years. The presence of a vaccination scar was taken as a proxy marker for BCG vaccination. The crude effectiveness was 8% (95% CI: -26 to 32) and the adjusted effectiveness was 30% (95% CI: -75 to 72). The present study suggests that BCG does not have a protective effect against tuberculosis among immunodeficient HIV-infected children. Since BCG is no longer given to HIV-infected children, the study may not be replicated. Accepting that these findings should be considered with caution, they are nonetheless likely to be the last estimate of BCG efficacy in a sufficiently powered study.