Induction of lepromin positivity following immuno-chemotherapy with Mycobacterium w vaccine and multidrug therapy and its impact on bacteriological clearance in multibacillary leprosy: report on a hospital-based clinical trial with the candidate antileprosy vaccine

Int J Lepr Other Mycobact Dis. 1999 Sep;67(3):259-69.


A vaccine based on autoclaved Mycobacterium w was administered, in addition to standard multidrug therapy (MDT), to 157 bacteriologically positive, lepromin-negative, multibacillary (LL, BL and BB) leprosy patients. The vaccinees were supported by a well-matched control group of 147 patients with similar type of disease who received a placebo injection in addition to MDT. The MDT was given for a minimum period of 2 years and continued until skin-smear negativity, while the vaccine was given at 3-month intervals up to a maximum of 8 doses. The lepromin response evaluated in terms of percentage of subjects converting to positivity status, measurement in millimeters, and duration of lepromin positivity sustained, reflected a statistically significant better outcome in the vaccine group patients (especially LL and BL leprosy) in comparison to those in the placebo group. The data indicate that lepromin-positivity status seems to have an impact on accelerating the bacteriological clearance, as is evident by the statistically significant accelerated decline in the BI of those patients who converted to lepromin positivity as compared to those remaining lepromin negative throughout therapy and post-therapy follow up. To conclude, the addition of the Mycobacterium w vaccine to standard MDT induces a lepromin response of a statistically significant higher magnitude than that observed with MDT alone.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Vaccines / administration & dosage*
  • Bacterial Vaccines / immunology
  • Clofazimine / immunology
  • Clofazimine / therapeutic use
  • Dapsone / immunology
  • Dapsone / therapeutic use
  • Double-Blind Method
  • Drug Therapy, Combination
  • Humans
  • Immunotherapy / methods
  • Lepromin / drug effects
  • Lepromin / immunology*
  • Leprostatic Agents / immunology
  • Leprostatic Agents / therapeutic use*
  • Leprosy / drug therapy
  • Leprosy / immunology
  • Leprosy / therapy*
  • Mycobacterium leprae / immunology*
  • Mycobacterium leprae / pathogenicity
  • Rifampin / immunology
  • Rifampin / therapeutic use
  • Single-Blind Method
  • Skin Tests
  • Vaccines, Inactivated


  • Bacterial Vaccines
  • Leprostatic Agents
  • Vaccines, Inactivated
  • Lepromin
  • Dapsone
  • Clofazimine
  • Rifampin