The BCG vaccine is a type of vaccine that provides immunity against tuberculosis. It is formulated using a weakened strain of bovine tubercle bacilli, the rod-shaped bacteria responsible for causing tuberculosis. The term BCG stands for “bacille Calmette-Guérin,” which is derived from the names of the two individuals who developed the tuberculosis vaccine.
The BCG vaccine is administered to individuals who are considered at risk of developing tuberculosis, as well as those who have tested negative on the tuberculin test, indicating a lack of immunity to the disease. Those at risk may include healthcare workers, individuals who have been in close contact with tuberculosis patients, and immigrants from countries with high tuberculosis rates. Infants born to immigrants falling into this category are typically immunized shortly after birth, without the need for a tuberculin test. Additionally, children between the ages of 10 and 14 who test negative on the tuberculin test are also recommended to receive the BCG vaccine.
The BCG vaccine is typically administered through an injection in the upper arm. Approximately six weeks following the vaccination, a small pustule tends to emerge at the injection site. Usually, this pustule heals completely, resulting in a small scar. However, in rare cases, it may progress into a persistent ulcer, forming an open sore.