Bacille Calmette-Guérin Vaccination: A Review of Clinical Effectiveness and Guidelines

Key Message

One health technology assessment, three systematic reviews of primary studies, and two non-randomized studies were identified regarding the clinical effectiveness of the BCG vaccine for the prevention of TB. One systematic review of guidelines and four evidence-based guidelines were identified regarding the use of the BCG vaccine in populations at risk of exposure to TB.

The evidence included in this report was mostly low- to moderate-quality with considerable heterogeneity and may be considered outdated. However, in people who are immunocompetent, the BCG vaccine consistently demonstrated a lower risk of TB compared those unvaccinated with BCG, however, the duration of the vaccine effectiveness was less certain. The BCG vaccine was also associated with a lower risk of morality compared to the unvaccinated population. Insufficient evidence was found on the adverse effects of the BCG vaccine. The BCG vaccine is recommended for people who are immunocompetent who have a high risk of exposure to TB, including: those who live in countries or settings with a high incidence of TB; those who have a family history of TB; those with potential occupational exposure to TB; and those travelling to countries with a high incidence of TB. Revaccination with BCG is not recommended.

The evidence identified in this report suggests that the BCG vaccine is not effective in people with HIV, and the BCG vaccine is not recommended in adults with HIV. Recommendations concerning BCG vaccination of newborns with confirmed or suspected HIV is less certain, and may depend on the risk of exposure to TB.