The leishmaniases are global diseases impacting millions. No vaccine against human leishmaniasis has yet been developed. What is needed is a rapid, cost-effective means for early evaluation of the efficacy of candidate vaccines. Our solution to this roadblock is a Controlled Human Infection Model (CHIM) of sand fly initiated Leishmania major infection.

The primary outcome of this project is the development of an effective Leishmania major human challenge model with 100% lesion clearance after treatment. The secondary outcomes include the measurement of immune response parameters and analysis of lesion development.

Collectively, this project will provide a new tool to assess vaccine efficacy and allow for evidence-based decisions to be made on the down selection and progression of candidate vaccines for leishmaniasis.

Development of a Leishmania major challenge model is part of a broader UK focus on developing Controlled Human Infection Model studies for vaccine development.

Project stages

Leish Challenge is split into two stages. The first develops the tools necessary to conduct a human challenge study, including a positive ethical opinion to proceed. The second stage represents a controlled human infection model (CHIM) study to fully develop the model.

Stage 1 of the project comprises four elements:

• Focus group discussions
• Validation/modification of a sand fly biting protocol using uninfected sand flies
• Establishment of a clinical parasite bank to provide a source of parasites for sand fly infection and human challenge
• Submission for ethical review for the human challenge.

Stage 2 brings these elements together in a CHIM study.