(A) DTH response (mm); (B&C) LTT response (mean O.D value) to SLD and ConA in normal, infected control, vector (pcDNA) control as well as LdTPI-DNA vaccinated hamsters on days 45 and 90 post challenge; (D&E) NO production (µM) to LPS and SLD in the naive macrophages co-incubated with supernatants of mononuclear cells isolated from LdTPI-DNA-vaccinated hamsters in comparison to the unimmunized infected controls, vector-immunized controls, and uninfected normal hamsters on day 45 and day 90 post challenge. The LdTPI-DNA vaccinated hamsters survived the challenges of L. donovani and remained healthy more than 8 months. In contrast, hamsters vaccinated with the pcDNA3 vector and infected control survived for day 90 p.c. Significance values indicate the difference between the vaccinated groups and infected group (*, p<0.05; **, p<0.01; and ***, p<0.001).