BCG (Bacille Calmette-Guerin) is a live vaccine given after birth to help protect infants and young children against the most severe forms of TB disease. It is generally given in countries where TB infection and TB disease are more common.
The following groups of people may have had the BCG vaccine:
- Persons born in countries with a high rate of TB
- Aboriginal persons from communities with high rates of TB
- Persons born in Quebec and Newfoundland from 1940 to early 1980’s
The protective effect of this vaccine decreases as a person ages and the closer they live to the equator. Because the vaccine is made from treated (attenuated) strains of TB bacteria, it may cause a person to have a false positive tuberculin skin test (TST).
People who have the BCG vaccine:
- May have a false positive TST
- Do not have permanent protection from TB
- May still be at risk of infection
- Could have a serious allergic reaction to the BCG vaccine