N Engl J Med

BCG revaccination fails to prevent sustained TB infection

May 12, 2025

Bacille Calmette-Guérin (BCG) revaccination didn’t provide protection against sustained M. tuberculosis infection in QuantiFERON-TB (QFT)-negative, HIV-negative adolescents. This findings suggest that alternative strategies are needed to enhance tuberculosis prevention in this population.

Study details: The phase 2b, double-blind, randomized, placebo-controlled BCG REVAX trial (NCT04152161) evaluated the efficacy of BCG revaccination in preventing sustained QFT test conversion in QFT-negative, HIV-negative adolescents. A total of 1,836 participants were randomized, with 918 receiving the BCG vaccine and 917 receiving placebo. The primary endpoint was sustained QFT conversion, defined as an initial positive QFT test followed by two additional positive tests at 3 and 6 months.

Results: After a median follow-up of 30 months, sustained QFT conversion occurred in 62 participants in the BCG group and 59 in the placebo group. The hazard ratio for sustained QFT conversion was 1.04 (95% confidence interval [CI], 0.73 - 1.48), indicating no significant difference between the groups. The vaccine efficacy point estimate was -3.8% (95% CI, -48.3 to 27.4). Adverse events were more frequent in the BCG group, primarily due to injection-site reactions.

Source:

Schmidt AC, et al; BCG REVAX Study Team. (2025, May 8). N Engl J Med. BCG Revaccination for the Prevention of Mycobacterium tuberculosis Infection. https://pubmed.ncbi.nlm.nih.gov/40334156/