ABSTRACT
Leprosy remains one of the major chronic infectious diseases, with estimates of the total number of cases ranging from 10 to 20 million people. The immunological defect seen in lepromatous leprosy patients that is their inability to mount a T cell response against M. leprae is an intriguing phenomenon. The most important observation was that inoculation of a mixture of killed M. leprae and Bacillus Calmette-Guerin into lepromatous leprosy patients resulted in a change in immunological status of the patients such that they developed responsiveness to M. leprae. The World Health Organization steering Committee for Research on the Chemotherapy of Leprosy has been carrying out trials in South India on the control of leprosy by limited period administration of multiple drug regimens. Much progress has been made towards understanding the basic immunological features of leprosy, towards better methods of studying the immunochemical structure of the causative organisms, and towards developing a vaccine.
