On day 21 after the booster, the hamsters of infected, BCG alone and vaccinated groups were challenged intracardially with 107 metacyclic promastigotes of L. donovani. Following parameters observed Body weight (a), spleen weight (b), liver weight (c) and Parasite burden (no. of amastigotes per 100 cell nuclei) in the spleen (d), liver (e), and bone marrow (f) on days 45, 60, 90 p.c. Data represent mean values standard errors (SE) at the designated time points in the experiments. The hamsters immunized with rLdH2-4+BCG and challenged with L. donovani exhibited an optimal reduction in parasite load in spleen, liver and bone marrow Significance values indicate the difference between the vaccinated groups and infected group (***, p<0.001).