What is Bacille Calmette Guerin (BCG) Vaccine?
Bacille Calmette Guerin (BCG) is the most widely used vaccination in the world. BCG is made of a live, weakened strain of Mycobacterium bovis, (a cousin of Mycobacterium tuberculosis, the TB bacteria). It was developed in the 1930’s and it remains the only vaccination available against tuberculosis today. It is used because it is effective in reducing the likelihood and severity of TB in infants and young children. That is especially important in areas of the world where TB is highly prevalent, and the chances of an infant or young child becoming exposed to an infectious case are high. In the United States BCG is not used, because TB is not prevalent and the chances are small that infants and young children will become exposed. Another reason BCG is not used in the United States is because it may cause a tuberculin skin test to convert from negative to positive. This can be confusing because the TB skin test is the best available test for TB infection, and widespread use of BCG would m
