Bigger Picture Goal, Eradicating Malaria
Breakthroughs in malaria research and control have led to a decline in malaria worldwide, but progress has stalled in recent years. In 2018, half of the world’s population was still at risk of malaria, with 228 million cases and 405,000 malaria-related deaths.
malaria cases in 2018
malaria-related deaths in 2018
Southeast Asia bears 53% of the global vivax burden
> 10 years
time it takes to develop a new vaccine or drug
New Proposed Approach
A New Potential Solution
To address these pressing concerns, Mahidol Vivax Research Unit (MVRU) and Mahidol-Oxford Tropical Medicine Research Unit (MORU), with funding from Wellcome, are developing a new research model that will allow researchers to safely and quickly test vaccine and drug candidates for P. vivax malaria.
MIST is the first research programme in Southeast Asia to use the human infection study model. These studies have contributed uniquely to the understanding, treatment, and prevention of a number of diseases including influenza, cholera, typhoid, and hepatitis.
Conducting this trial in Thailand is significant for multiple reasons. Because of genetic differences across populations, it is not clear whether the results of previous studies conducted in the US or UK can be extrapolated to countries like Thailand, where malaria is endemic. The MIST trial represents a major step forward that will allow researchers to better understand the biology and transmission of P. vivax, and study new drugs’ efficacy in a population where malaria occurs naturally.
Crucially, the study will also provide a source of P. vivax infected blood samples, a necessary precondition for enabling future vaccine trials. In addition to laying the foundation for future progress towards a malaria cure, implementing the human infection study model in Thailand is poised to reduce the time for vaccine and drug development by as much as 5-10 years.
Project overview and next step
There will be several phases of the MIST programme in Thailand. The first phase is scheduled to begin in early 2020. The project will continue through 2024 for a total of 5 years.
In the first month of the study, a rigorous health screening and review process will take place at the Mahidol University Faculty of Tropical Medicine (FTM) in Bangkok. Six healthy volunteers (men and women), between 20-55 years of age will be selected from a field of applicants. The first part of the planned study will proceed slowly for safety.
The 6 volunteers will be bitten by clean laboratory mosquitoes that are carrying Plasmodium vivax (the parasites used in the study are very sensitive to drugs). The volunteers will stay in special accommodation with medical support for two weeks, and have health checks daily. Blood tests – just a spoonful of blood – will be taken each day, then at the end volunteers will be asked to give a cupful of blood, then given treatments to cure the malaria infection.
The volunteers will be then treated with a standard course of oral Chloroquine, an established drug for P.vivax. They will be clinically evaluated twice daily and remain under laboratory supervision until the course is finished and two consecutive blood films test negative for the malaria parasite.
At this point volunteers will be released, but will check-in once daily while they complete a 2-week course of fully-observed oral Primaquine for radical cure of P. vivax hypnozoites and for prevention of repeat infections.
At 45 days and once more at 90 days after initial infection, volunteers will receive a thorough follow up assessment and blood test. Additionally, they will be contacted biweekly to ensure they remain healthy and asymptomatic.
Safety and Ethics
The studies in MIST are carefully planned and will be reviewed by the Faculty of Tropical Medicine’s Ethics Committee as well as the Oxford Tropical Research Ethics Committee. We will comply with the most stringent international safety and ethical guidelines for the conduct of clinical research studies.
Researchers will impose precise screening criteria to ensure that all volunteers are healthy and physiologically prepared for the trial. It is important to note that human infection studies are only used when there is already an available treatment for a disease. If volunteers should become ill, experienced medical care is close at hand. Researchers have a precise idea of the symptoms that volunteers might experience and can quickly treat them.