Does a history of BCG vaccination change the interpretation of a tuberculin skin test?
No. Bacille Calmette-Guerin (BCG) vaccine is given in many countries because it can protect children against some severe forms of TB disease. However, its efficacy in preventing TB in adults is variable and controversial. People from areas of the world where there is high incidence of TB are likely to be TB infected if they have a positive result to a tuberculin skin test. They are at risk of developing TB disease, even if they have been vaccinated with BCG.
