A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1+MPL-SE vaccine for use in the prevention of visceral leishmaniasis.

Healthy Indian adult volunteers, with or without a history of leishmaniasis, were evaluated for evidence of previous infection with Leishmania donovani based on the direct agglutination test (DAT). Three cohorts of 6 DAT-negative and 6 DAT-positive subjects were enrolled in an open-label, dose-escalating, uncontrolled clinical trial and received three injections of the LEISH-F1+MPL-SE vaccine (consisting of 5μg, 10μg, or 20μg recombinant Leishmania polyprotein LEISH-F1 antigen+25μg MPL®-SE adjuvant). The study injections were given subcutaneously on days 0, 28, and 56, and the subjects were followed through day 168 for safety and immunological endpoints. The vaccine was safe and well-tolerated in DAT-negative and DAT-positive subjects and induced T-cell production of IFN-γ and other cytokines in response to stimulation with the LEISH-F1 antigen. This clinical trial shows that the LEISH-F1+MPL-SE vaccine is safe and immunogenic in healthy subjects with and without history of previous infection with Leishmania donovani.