The bacille Calmette-Guérin (BCG) vaccination is 90 years old. It was first used in humans in 1921 and is named after the two scientists, Calmette and Guérin, who developed the vaccine over the course of 13 years while working at the Pasteur Institute in Paris.

TB has become a neglected disease, but it is particularly neglected in children. This article introduces the science of TB in children and describes childhood TB epidemics in different parts of the world.