Vaccination of humans against cutaneous leishmaniasis: Cellular and humoral immune responses

Abstract

Brazilian army conscripts were vaccinated against American cutaneous leishmaniasis by using nonliving polyvalent promastigote Leish vaccine 5 or Leish vaccine 6 (vaccines with five or six Leishmania stocks) with or without Corynebacterium parvum. No statistically significant differences in lymphocyte stimulation indices were found between vaccinated groups with or without C. parvum, but lymphocyte stimulation indices of all vaccinees were significantly higher (P < 0.001) than those of the placebo group. A correlation of 90% was found between positive skin test results and positive lymphocyte stimulation indices. Eight major antigens with estimated molecular masses of 13.5, 25, 40, 63, 73, 85, 97, and 160 kilodaltons were recognized by Leish vaccine 5 sera. Our finding also demonstrated the predominance of immunoglobulin M antibody in sera of vaccinated subjects and that a component of Leish vaccine 5, gp63, was immunogenic in humans both at the T-cell level and at the antibody level.