BCG vaccination of neonates, infants, schoolchildren and adolescents. Part I: Dose finding studies with BCG strain 1331 Copenhagen.

A BCG vaccine prepared from strain 1331 Copenhagen was given to newborns and infants in four logarithmically decreasing doses (expressed in VU = viable units): 25 X 10(4), 11 X 10(4), 5 X 10 (4), and 2.2 X 10(4). The efficacy of the vaccine was determined through the conversion rate (tuberculin skin test) with 2 and 10 T. U. of RT 23, AND 10 AND 50 I. U. of GT (Hoechst). The results indicated that the conversion rate is a function of the dose of VU of the vaccine, as well as of the units of tuberculin used for testing.