Describe if how the Bacillus Chalmette-Guérin(BCG) vaccine ,gives immunity
The Bacillus Calmette-Guérin (BCG) vaccine is a live attenuated strain of the Mycobacterium bovis bacterium, which is closely related to the bacterium that causes tuberculosis. When administered, the BCG vaccine stimulates the immune system to produce a specific response to the bacteria, which can confer some level of immunity against tuberculosis.
The BCG vaccine works by introducing the live attenuated bacteria into the body, which in turn activates the immune response. This immune response helps the body recognize and remember the bacteria, allowing for a more rapid and effective response if the individual is later exposed to tuberculosis.
Although the BCG vaccine is not 100% effective in preventing tuberculosis, it has been shown to provide some level of protection against severe forms of the disease, particularly in children. Additionally, the BCG vaccine is also believed to provide some degree of non-specific immunity, strengthening the overall immune response to a variety of infections.
Overall, the BCG vaccine provides immunity by training the immune system to recognize and fight off the bacteria that causes tuberculosis, potentially reducing the severity of the disease if infection occurs.