Vaccination of Swiss Albino mice against experimental visceral leishmaniasis with the FML antigen of Leishmania donovani

The FML antigen of Leishmania donovani in combination with saponin, aluminu m hydroxide (Al(OH)(3)) and Freund's incomplete adjuvant (FIA) was used in vaccines tested in an outbred murine model of visceral leishmaniasis, eithe r through intraperitoneal or subcutaneous routes, The humoral response was significantly higher in the groups treated with FML + saponin or FML + AI(O H)3 than in controls, both before and after the infection. Animals immunize d by the i,p. route developed higher antibody titres. A significant and spe cific reduction of parasitic load in relation to saline (85%, p < 0.01) and saponin (p < 0.025) controls, was seen in animals treated with FML i sapon in by the i.p. Coincidentally with this reduction, an increase in antibodie s of the IgG2a subtype was detected only in animals treated with FML ii sap onin i,p. A reduction of 88%: in parasitic load was achieved by the combina tion of FML + AI(OH)(3) (s,c.), but the Al(OH)(3) treatment itself accounte d for 68% of this protection. In our conditions, vaccination with FML + sap onin i.p. was superior to other treatments and had no toxic effect due to s aponin. (C) 1999 Elsevier Science Ltd. All rights reserved.