Protective effect of BCG vaccination in infant Asians: a case-control study.
BCG vaccination has been routinely offered to infant Asian children in Birmingham since 1965. We conducted a case-control study to assess the protective effect of this scheme. Altogether 108 Asian children aged under 13 years, born since 1965, received treatment for tuberculosis. For each case four controls were selected; they were matched to the case by month and year of birth, sex, and ethnic origin. Cases and controls were all born in Birmingham. Of the cases, 62 out of 108 (57%) had received BCG, and of the controls, 336 out of 432 (78%) had received BCG. The estimated protective efficacy of vaccination was 64% (95% confidence limits, 43% and 77%). Routine BCG vaccination in infant Asians confers useful protection against the development of tuberculosis in childhood.