Effectiveness of Bacillus Calmette-Guérin vaccination against severe childhood tuberculosis in China: a case-based, multicenter retrospective study.

BACKGROUND: Evidence varies regarding the efficacy of Bacillus Calmette-Guérin (BCG) vaccine. Data on protection by BCG vaccination against severe tuberculosis (TB) among children in China remain unclear. METHODS: We conducted a case-based, multicenter retrospective study at three children's hospitals in China. Sociological factors affecting BCG vaccination and risk factors associated with disease types were analyzed using a multivariable model. RESULTS: A total 1701 children with active TB were enrolled. Children who were younger, female, residing in a rural area, living in the western regions, and with no BCG vaccination history were at higher risk of developing severe TB. Children with a BCG scar had significantly lower risk for severe TB (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.51-0.67). Children with no BCG scar but who were vaccinated at birth still had lower risk of severe TB types, such as tuberculous meningitis (OR 0.88, 95% CI 0.80-0.97) and miliary TB (OR 0.77, 95% CI 0.69-0.87). CONCLUSIONS: Neonatal BCG vaccination could be an effective means to control TB. In the absence of a new, more effective TB vaccine, our results lend support to continued use of the BCG vaccine in China.