The full form of BCG is Bacillus Calmette-Guerin. It is a vaccine given to protect against tuberculosis. Two French Bacteriologists named Camille Guerin and Albert Calmette had developed it in 1921. Over the years, it was adopted by several countries in order to vaccinate them against TB. Apart from that, it is also given to people who suffer from Bladder Tumour or Bladder Cancer. BCG vaccine is Mycobacterium Bovis’ weakest strain. It is one of the bacteria responsible for causing TB. BCG vaccine helps the human body to produce antibodies against the TB virus leading to immunity against TB.