Until a decade ago, the conquest of tuberculosis seemed one of the great triumphs of modern medicine. The resurgence of TB in the wake of AIDS has to be understood, Georgina Feldberg argues, in the context of decisions the U.S. Public Health Service made, beginning in the 1930s, to prevent TB through improved hygiene and long-term treatment with medications, rather than program of BCG vaccination that Canada and many other countries adopted. Feldberg’s aim is not to judge which was the right choice, but to explain why the U.S. rejected the vaccine and the consequences of that choice.