Study to Evaluate the Leish-111f + MPL-SE Vaccine in Healthy Adults Not Previously Exposed to Leishmania Parasite

Cutaneous leishmaniasis is a disfiguring disease that can progress to mucosal leishmaniasis, a more serious and possibly fatal form of Leishmania disease. All available medical therapies require weeks of treatment and cause significant toxicity. It appears that Leishmania infections can be eliminated or prevented by T helper 1 immune responses. These findings argue that a vaccine that generates a T helper 1 response against the parasite will prevent the infection and disease. This is a phase 2, randomized, double blind, placebo-controlled study to evaluate the safety, tolerability and immunogenicity in Montenegro skin test (MST)-negative healthy adults of an investigational vaccine being developed for the prophylaxis of cutaneous leishmaniasis. The vaccine, identified as Leish-111f + MPL-SE, consists of a recombinant three-antigen Leishmania polyprotein (Leish-111f, 10 μg) together with the adjuvant MPL-SE (25 μg). In addition, the safety and immunogenicity of the vaccine will be compared to that of the Leish-111f protein (10 μg) given alone. The vaccine, Leish-111f protein alone or placebo will be given to each study subject three times at 4 week intervals.