Addition of immunotherapy with Mycobacterium w vaccine to multi-drug therapy benefits multibacillary leprosy patients

Immunotherapy with a vaccine consisting of autoclaved Mycobacterium w, was given in addition to standard chemotherapy (multidrug therapy (MDT)) to 93 multibacillary (MB) leprosy patients. One hundred and seven patients with similar types of disease served as controls and received MDT + placebo injections. The study was a double-blind randomised trial. On opening the codes, results obtained were in concordance with those in a single-blind trial which has been extensively reported. Bacteriological clearances were significantly more rapid in vaccinated patients (p < 0.03). Thirty-five LL or BL patients with a high bacterial index (BI) of 6 were completely cleared of acid-fast bacilli (AFB) after eight doses of vaccine. Only 8 patients in the control group became bacteriologically negative in the same time period. They all had BIs < 4. Associated with decreasing BI was accelerated clinical regression of lesions after vaccination and lepromin conversion rates of 100% for BB, 71% for BL and 70% for LL. A significant number of immunised patients showed histological improvement (p < 0.004). Thirty-six showed a complete disappearance of dermal granulomas and a picture of non-specific infiltration. The vaccine did not precipitate neuritis or deformities; episodes were noted in vaccinated patients as were incidences of Type 2 reaction. The overall improvement was reflected by a shorter duration of treatment and faster release of vaccinated patients.