What type of vaccine is typically used for tuberculosis?

The vaccine typically used for tuberculosis is a live attenuated vaccine. This vaccine, known as Bacillus Calmette-Guérin (BCG), is made from a weakened strain of the Mycobacterium bovis bacterium, which is closely related to the bacterium that causes tuberculosis in humans. The use of a live attenuated strain helps to stimulate a strong and long-lasting immune response without causing the disease itself in healthy individuals.

Live attenuated vaccines are effective because they mimic an actual infection, leading to a robust activation of the immune system. This activation includes the production of antibodies and the generation of memory T cells that help the body recognize and fight the actual pathogen if encountered in the future.

Other types of vaccines, such as inactivated vaccines, would use killed pathogens and typically elicit a weaker immune response, making them less effective for certain diseases. Subunit vaccines consist of only parts of the pathogen, which may not provide the same level of immune memory. DNA vaccines involve genetic material but are not yet widely used for diseases such as tuberculosis. The use of the live attenuated BCG vaccine remains a key strategy in controlling tuberculosis, especially in countries with high rates of the disease.