A live attenuated vaccine for leishmaniasis

More than 12 million people suffer from leishmaniasis, a tropical disease which causes significant tissue destruction and disfigurement and can be life-threatening. The disease is spread by infected sand flies and animals, mainly dogs. The most life-threatening form of the disease is visceral leishmaniasis (VL), which is the second most fatal parasitic infection after malaria. No vaccine exists but patients who recover, develop immunity against reinfection, indicating that a vaccine is feasible.

We have generated genetically modified live weakened Leishmania parasites. Preclinical studies show that these weakened parasites are safe and induce protective immunity against infection. We will test the safety and effectiveness of using weakened Leishmania parasites as a vaccine in a novel canine model of VL.

This study could represent a major step forward for the development of a human vaccine for VL, as well as a vaccine for dogs to reduce their risk as carriers.