Immune responses to an inactive vaccine against American cutaneous leishmaniasis together with granulocyte-macrophage colony-stimulating factor

The immunological response in healthy subjects to a crude leishmania antigen vaccine (Leishvacin) plus rhGM-CSF without prior Montenegro (DTH) skin testing was evaluated. Fifty-six healthy volunteers received vaccine plus either placebo or rhGM-CSF at day 0, followed by either a vaccine booster or placebo at day 21. IFN-γ and IL-5 levels were significantly enhanced by day 21. The adjuvant group had a higher percentage of individuals with a significant response to vaccination than the corresponding placebo group. Eighty-six percent of all volunteers were DTH-positive by day 42. Leishvacin is capable of sensitizing lymphocytes from individuals not previously exposed to leishmania antigen. Use of rhGM-CSF enhanced the immune response, indicating that it may improve immunological response to the vaccine.