ASSESSMENT of BCG vaccination in India. II. WHO Tuberculosis Research Office.

A second assessment of the mass BCG-vaccination campaign in India is described in this report. Data were collected to corroborate the findings of the first assessment and to study certain aspects of the problems they posed.Sample retesting of children vaccinated in the mass campaign reveals a higher and less variable allergy than that reported from the preliminary assessment work. The results indicate that a uniform and reasonably high level of allergy has been induced in Indian schoolchildren vaccinated in the campaign period assessed and that deficiencies in the tuberculin test by which the allergy was measured rather than defects of vaccine or vaccination technique were responsible for the disappointing variability initially reported.Testing of unvaccinated village populations in Madras and Mysore confirms previous observations that low-grade, non-specific tuberculin sensitivity is widely prevalent in South India, making it virtually impossible to separate the infected from the uninfected with the tuberculin tests in use today. The development of new techniques for use in areas where the low-grade, non-specific sensitivity is widespread is discussed.