BCG vaccination and WHO's global strategy for tuberculosis control 1948-1983.

Mass vaccination with BCG against tuberculosis has been one of the major health interventions of WHO since the Second World War. This article traces the history of the controversial BCG vaccine from its adoption by WHO in 1948 up to 1983. In 1948, there was no clear scientific evidence to support the vaccine, and its adoption by WHO seems to have been urged by the existence of the UNICEF funded 'International Tuberculosis Campaign' and a fear of a threatening global epidemic. Moreover, BCG fitted well with the post Second World War perception of public health interventions. The vaccine was not systematically reviewed by WHO until 1959, and this review appears to have been biased in favour of the vaccine. In 1979 the results from the South Indian Chingleput trial, which showed no protective effect of BCG against pulmonary tuberculosis in adults, prompted WHO to change the arguments for recommending the vaccine. Since 1983 BCG has been recommended with specific reference to its protective effect against severe forms of childhood tuberculosis. The story of the BCG vaccine and WHO is a story of medical uncertainty, institutional inertia, strategic obduracy, and not least, hope.