Resistance against Leishmania donovani induced with an aluminum hydroxide vaccine.

Mice immunized with a subcutaneous protocol combining killed parasites and aluminum hydroxide gel exhibited significant resistance against subsequent challenge with Leishmania donovani promastigotes. Protection was greatest using 25 mg of aluminum hydroxide per injection. Resistance elicited by this killed parasite and aluminum hydroxide protocol was as effective on day 14 as that provided by immunization with a glucan and killed parasite preparation, and more effective in hepatic amastigote reduction at day 28. The effectiveness of aluminum hydroxide as an adjuvant appears to result, at least in part, from its ability to activate macrophages, thus aiding in the elimination of this intracellular parasite.