Antituberculous immunity: new solutions to an old problem.

Tuberculosis continues to be a serious public health problem worldwide. In Europe and the United States, it is now primarily a disease of the elderly; the alcoholic; the drug abuser; Central American, African, and Asian immigrants; and patients with AIDS. New and improved antituberculous vaccines are urgently needed, as both prophylactic and therapeutic agents. Recent advances in molecular biology, genetic engineering, and hybridoma technology make it possible to identify and clone the genes thought to be responsible for the production of the protective antigens (or epitopes) of Mycobacterium tuberculosis. These antigens are produced by the pathogen as it multiplies within the lymphoreticular organs of the infected host. The "protective" genes can be transferred to suitable expression vectors by means of shuttle phasmids, making possible the development of specifically tailored vaccines capable of protecting infants and young adults more effectively against pulmonary tuberculosis and immunocompromised individuals against the disseminated form of this disease.