A Phase 1 double-blind placebo-controlled study was performed to
evaluate a vaccine against American tegumentary leishmaniasis in 61 healthy
male volunteers. Side effects and the immune response to the vaccine were
evaluated, with 1- and 2- dose schemes, with intervals of 7 or 21 days,
each dose containing 1440 mg of protein N antigen of a single strain of
Leishmania amazonensis (PH 8) diluted in merthiolated saline
(1:10,000). Merthiolated saline and an inert substance were used as
placebos. No significant clinical alterations were found following the
respective injections in the vaccinated individuals as compared to the
placebos, except for local pain, which was associated significantly with
injection of the vaccine. The laboratory alterations we observed bore no
association with the clinical findings and were unimportant. We observed no
differences between the groups with regard to seroconversion or the
Montenegro skin test. However, the group that received a single dose of the
vaccine and the one that received two doses with a 21-day interval
displayed cutaneous induration significantly larger than in the control
group, with 100%, 100%, and 66% conversion in the skin test, respectively.
We concluded that the vaccine does not present any major side effect that
would contraindicate its use in healthy individuals.
