The invention relates to a vaccine composition, made of excreted/secreted proteins from promastigotes and/or amastigotes of Leishmania sp., for preventing or treating leishmaniases in mammals, preferably in canidae, to a method for preparing said composition, and to the uses thereof. Said composition consists of: excreted/secreted proteins (ESPs) from promastigotes and/or amastigotes of Leishmania sp., produced in a germ-free, non-serous medium substantially pure saponin QA21 and optionally, a pharmaceutically acceptable carrier.