Comments on the new analysis of the Chingleput BCG trial.

E: BCG VACCINE TRIAL 187 GVJ Baily: THE EFFICACY OF BCG VACCINATION - A BRIEF REPORT OF THE CHINGLEPUT BCG TRIAL

Problems with ascribing between-trial differences in BCG effectiveness to sensitization with environmental mycobacteria.

TO THE EDITOR—Mangtani et al recently analyzed the results of 21 trials of BCG vaccination [1], finding that “latitude and age at vaccination/tuberculin testing stringency could explain all of the betweentrial heterogeneity.” They conclude that the “absence of prior M. tuberculosis infection or sensitization with environmental mycobacteria is associated with higher efficacy of BCG against pulmo...

Reply to Kernodle and von Reyn.

TO THE EDITOR—We thank Kernodle [1] and von Reyn [2] for their comments. We are glad that von Reyn finds our article [3] a useful clarification of factors explaining the wide range of efficacy of BCG in trials and that it will help inform design of new trials. We recognize the limitations of meta-regression, were careful to acknowledge and discuss these, and are pleased to contribute further. K...

Influence of sex, age & nontuberculous infection at intake on the efficacy of BCG: re-analysis of 15-year data from a double-blind randomized control trial in South India.

BACKGROUND & OBJECTIVE To estimate the efficacy of BCG in preventing tuberculosis over a 15-year period, and also to assess the impact of infection with nontuberculous environmental mycobacteria in a rural community in Chingleput district in Tamil Nadu in south India. We re-analysed the 15-year follow up data of a large randomized trial conducted earlier. METHODS A double-blind randomized con...

BCG vaccine and pulmonary tuberculosis

Tuberculosis (TB) is one of the most important public health problems in the world and has been declared as a global emergency by the World Health Organization (WHO) in 1993. Bacillus Calmette-Guérin (BCG) is one of the first developed vaccines to prevent TB. Unfortunately, BCG vaccine has had a limited duration of protection and has shown controversial and variable levels of efficacy, especial...