The Impact of BCG Vaccine on Tuberculin Reactivity in Healthy Children below 6 years

• In our locality BCG vaccine induces tuberculin reaction of less than 15 mm; most of the reactions are below 10 mm. reaction between 10 and 15 mm should be interpretated with caution since one child with reaction 10-15 mm was acontact of active TB case.• BCG vaccine success rate is 84.3% if we consider BCG induced scar and 50.7% if we consider positive TST. However 49.3% of our studied children was tuberculin negative.