[BCG vaccination]. 
Given especially to children, BCG vaccine has a protective effect against severe forms of tuberculosis in 70 to 80% of the subjects.  It has a modest epidemiological effect since socioeconomic and sanitary conditions as well as human immunodeficiency virus infection influence disease spread.  The precise mechanisms and the duration of BCG protection remains poorly defined.  Vaccine complications in HIV positive subjects appear minimal compared with expectations.  The tuberculosis irradication policy is defined in each country depending on the annual risk of infection.  The threshold of 0.01% (0.03% in France) would justify BCG vaccination of exposed persons alone.  Today there is renewed interest in research concerning BCG, 70 years after its first introduction for clinical use.