Abstract: The invention provides a DNA vaccine that elicits an immune response in the host in which it is administered, against Leishmania infection. The invention also relates to methods of administering the DNA vaccine. In one embodiment the DNA vaccine contains a vector encoding the A2 gene from Leishmania donovani in a physiologically acceptable medium. The invention further contains a biological adjuvant that includes a vector encoding a selected gene, the selected gene being capable of mediating the degradation of the cellular protein p53.