Short report: Evaluation of the potency and stability of a candidate vaccine against American cutaneous leismaniasis

Availability of a safe, immunogenic, and affordable vaccine would represent the best strategy for control of cutaneous leishmaniasis (CL). Stability i n field conditions is a essential property for any candidate vaccine. The s tability and immunogenicity of three different preparations (thimerosal-pre served, autoclaved, and lyophilized) of a killed Leishmania amazonensis vac cine were assessed using fresh products and after 12 months of storage at 4 degrees C. Autoclaving was associated with a time-dependent decrease in th e immunogenicity of the vaccine, as measured by the leishmanin skin test an d production of interferon-gamma. These findings are of importance in the d ecision of which preparation of candidate killed CL vaccines should move to phase III trials.