Calmette Guerin Bacillus, commonly known as BCG, is a strain of bacteria derived from Mycobacterium bovis, which causes tuberculosis in cattle. The abbreviation BCG refers to Bacillus Calmette Guerin, named after Albert Calmette and Camille Guerin, the French scientists who developed the strain. BCG is widely recognized for its use as a vaccine against tuberculosis and as a therapeutic agent for certain types of cancer.
The BCG vaccine is made from live, weakened Mycobacterium bovis bacteria, which have been attenuated to reduce their virulence but still retain the ability to stimulate an immune response. When the BCG vaccine is administered, it triggers the body's immune system to produce a response, including the activation of immune cells and the production of antibodies specific to Mycobacterium tuberculosis, the bacterium responsible for human tuberculosis. This immune response provides protection against future infections with Mycobacterium tuberculosis.
In addition to its use as a vaccine, BCG has also shown promise in the treatment of bladder cancer. It is typically administered directly into the bladder, where it stimulates the immune system and activates immune cells to attack and destroy cancer cells. BCG therapy has been proven effective in reducing tumor recurrence and preventing disease progression in non-muscle invasive bladder cancer.
Although BCG is generally safe, it can cause local and systemic side effects, including granulomas at the injection site, fever, and malaise. In rare cases, severe complications such as disseminated BCG infection can occur, particularly in individuals with weakened immune systems.
