It is the most widely used vaccine worldwide, with more than 90% of all children being vaccinated. The immunity it induces decreases after about ten years. As tuberculosis is uncommon in most of Canada, the United Kingdom, and the United States, BCG is administered only to those people at high risk. Part of the reasoning against the use of the vaccine is that it makes the tuberculin skin test falsely positive, reducing the test's use in screening. A number of new vaccines are currently in development. COUNT 5
QSN1 For about how long does full immunity from the TB vaccine last? ANS1 ten years QSN2 What percentage of kids in the whole world get the BCG vaccine? ANS2 90% QSN3 Is TB common or uncommon in the United States? ANS3 uncommon QSN4 In addition to the U.S. and Canada, what European country sees very few tuberculosis infections? ANS4 the United Kingdom QSN5 What segment of the population gets the TB vaccine in countries like Canada with a very low incidence of infection? ANS5 high risk