- Bacillus Calmette-Guérin (BCG) vaccine was associated with a lower prevalence of latent tuberculosis infection (LTBI) in adults with recent exposure to active tuberculosis.
Why this matters
- Findings contribute to growing evidence that BCG may provide protection against Mycobacterium tuberculosis (Mtb) infection as well as disease.
- It has implications for immunisation programmes, vaccine development, and tuberculosis control efforts worldwide.
- Cross-sectional study of 3453 contacts of patients with LTBI who participated in the UK PREDICT study.
- Vaccine effectiveness of BCG ascertained against LTBI, measured through interferon-gamma release assays (IGRAs).
- Funding: None disclosed.
- Of 3453 patients, 86.9% (3000/3453) had received BCG vaccination.
- The overall prevalence of LTBI was 27.5% (951/3453), 27.0% (809/3000) in those vaccinated and 31.4% (142/453) in the unvaccinated.
- After adjustment for confounders, significant association was observed between BCG and LTBI (OR, 0.70; 95% CI, 0.56-0.87; P=.0017).
- In those vaccinated at age ≤2 years, protection was greater in those vaccinated 11-20 years ago (OR, 0.55; 95% CI, 0.33-0.90) than those vaccinated >20 years ago (OR, 0.78; 95% CI, 0.60-1.00).
- Observational design cannot prove causality.
- Risk of confounding.