La vaccination BCG en France

: First used in 1921 and obligatory since 1950, BCG vaccination is a part of the classical arsenal in the struggle against tuberculosis in France. The progressive reduction in the incidence of tuberculosis leads one to wonder what to expect now and in the future, so much so that the degree of protection conferred by BCG is continually discussed. In animal experiments, BCG vaccination is efficacious but there is no absolute protection conferred. In man, the results of 9 prospective studies performed with control groups have thrice shown an 80% protection, thrice a 30% protection and thrice no protection (in the case of studies from Southern India). On the grounds that there were large differences in the methodology of the 9 studies and that the best methodology was found in the 3 studies which showed good protective efficacy of BCG, it is justifiable to consider that the protection conferred against tuberculosis by a correct BCG vaccination is of the order of 80% and lasts 15 years (direct effect of BCG). Equally, a similar protection has been observed in numerous retrospective studies. But it is not accompanied by a reduction in the transmission of tuberculous bacilli in the population vaccinated with BCG. Since one does not observe any reduction in the incidence of tuberculosis in non-vaccinated subjects who live in contact with the vaccinated population (indirect effect of BCG).(ABSTRACT TRUNCATED AT 250 WORDS)