 Disseminated infection with Mycobacterium tuberculosis dMTB has been documented in 10 to 25 of patients with HIV infection in Africa. Unlike pulmonary tuberculosis pMTB, most cases of dMTB are not recognized and death ensues rapidly. Therefore, dMTB may be a more important cause of HIV-associated mortality than pMTB in developing countries. Mycobacterium vaccae MV is an investigational vaccine prepared by heat inactivation of a nontuberculous mycobacteria. MV immunization may reduce the risk of HIV-associated dMTB. The purpose of this study is to define risk factors for HIV-associated dMTB and to assess the safety and effectiveness of an MV vaccine for the prevention of HIV-associated pulmonary and disseminated tuberculosis. 