Controlled Human Malaria Infection

Background. Since 1986, investigators at Walter Reed Army Institute of Research (WRAIR) have been using controlled human malaria challenge (CHMI) in malaria-naive adults in order to define the protective efficacy of a malaria vaccine and thus guide programmatic decisions on vaccine candidates. Adapting this model to the dengue field could provide similar evidential support for a vaccine or therapeutic product. Methods. After completing a vaccine regimen, volunteers are bitten by 5 malaria-infected female Anopheles mosquitoes in a controlled environment. Volunteers are then monitored daily for peripheral parasitemia in a hotel setting with 24-hour access to a nurse and physician. If a single verified parasite is detected, effective antimalarials are promptly administered. Results. The vast majority of the over 1000 volunteers having participated in CHMI clinical studies have done so at US military research centers. Numerous pre-erythrocytic and erythrocytic vaccine candidates have been evaluated safely and without any related serious adverse events using this model, including the soon-to-be licensed RTS, S malaria vaccine. Conclusion. The lessons learned from over 25 years of experience in consistent, careful preparation and execution of the CHMI model at WRAIR can provide a foundation from which the dengue field can begin to develop a rigorous and safe CHDI model.