What type of vaccine is commonly used for Tb?

The correct answer is that the vaccine commonly used for tuberculosis (TB) is a live attenuated vaccine. This vaccine, known as the Bacillus Calmette-Guérin (BCG) vaccine, consists of a weakened form of the Mycobacterium bovis, which is closely related to the bacterium that causes TB in humans. The live attenuated approach stimulates a robust immune response without causing the disease, as the pathogen is altered to reduce its virulence.

Employing a live attenuated vaccine is particularly effective because it helps in developing a long-lasting immune response. It mimics a natural infection, which is crucial for establishing immunity against TB, especially in populations at high risk. The BCG vaccine is most effective in preventing severe forms of TB in children, such as extrapulmonary TB and TB meningitis.

Other types of vaccines mentioned, like inactivated vaccines, synthetic peptide vaccines, and subunit vaccines, are not utilized for TB because they may not provide the broad and effective immune response necessary to combat this complex disease. Inactivated vaccines typically contain pathogens that have been killed, which usually require boosters to maintain immunity. Synthetic peptide and subunit vaccines typically use parts of the pathogen to elicit an immune response, which may