This article demonstrates that BCG revaccination when tuberculin test results are used as the reason for the revaccination of people with doubtful reactions or no reactions at all should be considered outdated. To show this a brief exposition on tuberculin sensitivity and acquired resistance to tuberculosis and then the technical background of the tuberculin test are presented followed by comments concerning tuberculin profiles of general population groups. Individual variations in BCG - induced allergy raise questions about a possible correlation of post-vaccination allergy and resistance. Epidemiological data and experimental facts, however, demonstrate that the degree of protection given the individual is not proportional to the degree of tuberculin skin sensitivity induced by vaccination. Recent findings show that lymphocytes from BCG vaccinated children retain sensitivity to tuberculin years after vaccination and even when skin reactivity has disappeared. Finally, tuberculin testing for the evaluation of BCG vaccination is discussed.
BCG vaccination; Tuberculin test
