Clinical considerations in designing trials of vaccines for tuberculosis.

Despite remarkable strides in the treatment of tuberculosis, the disease continues to be a major public health problem in many parts of the world, a situation that is projected to remain unchanged for years into the future. The development of a highly effective vaccine could substantially reduce the magnitude of the tuberculosis problem. A tuberculosis vaccine could theoretically prevent initial infection by Mycobacterium tuberculosis and enhance host response to prevent the progression from infection to disease or even to augment response to treatment in cases of established disease. Assessment of candidate vaccines will require clinical trials. This article suggests how traditional end points of morbidity and mortality, a number of newer measures of disease impact, and surrogate markers of tuberculous infection and disease might be used in such studies.