A field trial was carried out in the eastern part of the State of Minas Gerais (Brazil) of a vaccine containing killed promastigotes of five stocks of Leishmania. Tests with Montenegro antigen showed that a high proportion of the vaccinated persons became positive within three months, but circulating antibodies were not detected. A proportion of those vaccinated continued to give positive Montenegro reactions for up to three years. Lymphocyte sensitivity tests carried out, on a small sample, three years after vaccination were positive and gave no evidence of immunological depression. No cases of cutaneous or mucocutaneous leishmaniasis occurred in the trial area during the three years of observations.

No abstract

Two controlled, double blind field trials of a non-living promastigote vaccine against New World Cutaneous Leishmaniasis (NWCL) were conducted in 1981 and 1983 in Brazil. Brazilian Army conscripts were randomly assigned to the vaccine or placebo groups and tested during their training in the Amazon jungle, a high risk area for NWCL. The results obtained showed: no significant differences between the vaccine and the placebo groups with respect to a number of characteristics (age, race, previous contact with the jungle, etc.); no significant differences between the participants who got and who did not get NWCL during the trial, with respect to length of exposure, contact with the jungle, etc. and a reduction of 67.3 and 85.7% in the annual incidence rate of NWCL, in 1981 and 1983 respectively (although the difference between incidence rates of the disease in vaccinated and control groups in the 1983 trial was not statistically significant), among those vaccinated who had converted to a positive leishmanin skin test as compared with the placebo groups.