BCG vaccine administered on children is to build immunity against

The BCG vaccine is a vaccine that is administered to children to help build immunity against tuberculosis. Tuberculosis is a bacterial infection that mainly affects the lungs but can also affect other parts of the body. It is a serious infectious disease that can be spread through the air when an infected person coughs or sneezes. The BCG vaccine contains a weakened strain of the bacteria that causes tuberculosis, which stimulates the body's immune system to produce a response that helps to protect against the disease. While the BCG vaccine may offer some protection against other related bacteria, it is mainly used to prevent tuberculosis. It is important to note that the BCG vaccine is not 100% effective, and other measures such as good hygiene practices are also necessary to prevent the spread of tuberculosis.