RESUMO
SETTING: Infants identified in maternity hospitals in Vilnius, Lithuania. OBJECTIVES: To test the capacity of the BCG vaccine, Danish strain 1331 (Danish vaccine), to induce tuberculin reactivity and scar formation in neonates compared to the WHO International Reference Preparation of BCG (IRP vaccine), and to study the effect of dose and of age at vaccination. DESIGN: A randomized four-armed study: 1) normal dose, 0.05 ml Danish vaccine given to neonates at birth, 2) half the normal dose of Danish vaccine given at birth, 3) IRP vaccine given at birth at normal infant dose, and 4) the normal infant dose of Danish vaccine given at 3 months of age. RESULTS: Larger tuberculin reactions, as well as an increased frequency and larger scars, were seen when Danish vaccine was given at 3 months of age in comparison to neonatal vaccination. Halving the dose resulted in smaller reactions, but the difference was not significant. The IRP vaccine resulted in borderline significantly larger reactions in comparison to the Danish vaccine. The number of infants receiving very early vaccination (0-2 days) was not evenly distributed in all groups, however, which is believed to explain the observed difference.