First vaccine for Leishmaniasis

A team of researchers have developed a possible first vaccine for Leishmaniasis, a protozoal parasitic disease spread by the bite of certain types of sandflies that affects the skin, muco-cutaneous membranes or internal organs.

Most human vaccines work by stimulating the body’s immune system, specifically the B cells, to produce antibodies. However, because of the vigorous immune response triggered by Leishmania antigens, this approach has proven ineffective against the disease.

Recently, an international team of researchers has developed a DNA vaccine against Leishmania that induces an immune response dependent on the activation of T-cells instead, publishing their findings in Science Translational Medicine¹.

The team identified antigens that belong to conserved protein families in different species of the Leishmania parasite from various endemic regions. By using T cells from the blood of individuals who had been cured of Leishmaniasis, they made sure these antigens also elicited a T-cell-mediated immune response in humans. The DNA vaccine developed from these antigens protected mice when they were injected with it.

The vaccine may prove promising if approved for testing on humans, and could open the door for the development of other T-cell-based vaccines. “We hope soon to be able to proceed to the clinical testing of this vaccine against one of the most neglected infectious diseases,” said Peter Walden from Charité–Universitätsmedizin Berlin in Germany and one of the study leaders.