E-Mail Researchers have taken an important step forward in developing a controlled human infection model to test leishmaniasis vaccines. The University of York-led study identified and characterised a new strain of Leishmania parasite that will form the basis of a new controlled human infection model for the disease which is transmitted by the bite of sand flies. The team then produced the parasite to the standards required for use in human clinical studies. The use of controlled human infection models has already proved invaluable in accelerating vaccine development for cholera, malaria, typhoid, influenza and other important infectious diseases. Such models are also being developed as part of the fight against COVID-19.