Bacillus Calmette-Guérin (BCG) Vaccine is a specific type of vaccine used for the prevention and treatment of tuberculosis (TB) and bladder cancer. It is named after the two French microbiologists Albert Calmette and Camille Guérin, who developed it in the early 1920s.
The BCG vaccine is composed of weakened strains of Mycobacterium bovis, a bacterium closely related to Mycobacterium tuberculosis, the causative agent of TB. Through the process of attenuation, the virulence of the bacterium is reduced, making it safe for use in humans.
When administered, typically through intradermal injection, the BCG vaccine stimulates an immune response. It activates immune cells, particularly T-cells, to recognize and target Mycobacterium tuberculosis or cancer cells specific to bladder cancer. This immune response forms a memory against the bacterium or cancer cells, providing long-term protection. In tuberculosis prevention, the vaccine is primarily administered to infants and young children in countries with a high prevalence of TB.
Despite being the only licensed vaccine for TB, the efficacy of BCG varies, offering partial protection against severe forms of childhood TB but limited protection in adults. It is essential to note that the BCG vaccine is not a replacement for comprehensive TB control strategies such as early diagnosis, proper treatment, and infection control measures.
BCG vaccination is generally considered safe, with the most common side effect being a localized skin reaction at the injection site. Rarely, serious complications may occur, especially when given to individuals with compromised immune systems, such as those with HIV or malnutrition.
In conclusion, the Bacillus Calmette-Guérin vaccine is a weakened form of Mycobacterium bovis that is used to prevent and
