摘要：The Bacille Calmette-Guérin (BCG) vaccine since its fi rst use in 1921 has been the subject of much con-troversy as to its effectiveness and applicability. BCG vaccination is still considered an important strategy in the National Tuberculosis Programs of countries with a high burden of tuberculosis (TB) because of its benefi t to infants but its effect on the control of TB has been limited. By contrast, in countries with a low prevalence of TB, signifi cant policy differences exist both within and between countries
