The BCG vaccine (Bacillus Calmette–Guérin) is a vaccine primarily used to prevent tuberculosis (TB), especially severe forms like TB meningitis and miliary TB in children. It is made from a weakened strain of Mycobacterium bovis, a cousin of the bacteria that causes TB.Importance: • Prevents severe TB in children. • Helps reduce TB transmission in high-risk areas. • Often given to newborns in countries where TB is common.Reaction: • After vaccination, a small red bump appears at the injection si