Completed Infection & Immunity Digestion, Kidneys & Other Organs

Plasmodium vivax Volunteer Infection Studies in Thailand

Funder Wellcome Charity-funded
Recipient organisation University of Oxford
Funding £3.0M
Period Sept 2018 — Nov 2023

In plain English

AI plain-English summary

Malaria researchers in Thailand will deliberately infect semi-immune volunteers with *Plasmodium vivax* to test four vaccine candidates and develop models for future drug trials. The problem is that *P. vivax* malaria is harder to eliminate than the better-known *P. falciparum* because it hides in the liver as dormant hypnozoites, causing relapses months after the initial infection. No vaccine exists, and current anti-relapse drugs have side effects that limit their use. Testing vaccines in the field is slow and expensive, requiring thousands of participants over years. The team will run six controlled human infection studies, where volunteers bitten by infected mosquitoes are closely monitored and treated. This approach lets researchers rapidly measure whether a vaccine blocks infection or prevents blood-stage disease, and identify which immune responses correlate with protection. The studies will also include social science and ethics research to gauge whether local communities, patients, and policymakers find such deliberate infections acceptable. If successful, this programme will create a reliable testing platform in a malaria-endemic country, accelerating development of vaccines and safer anti-relapse drugs for the populations that need them most.

View original technical description
Vivax malaria remains a major global health problem. Because of the existence of a hypnozoite stage and the clinical relapses this causes, elimination strategies are more difficult to design and implement successfully than for falciparum malaria. Vaccines and new well-tolerated anti-relapse drugs are badly needed. To accelerate vaccine development, we will develop and assess the feasibility of conducting Plasmodium vivax volunteer infection studies in Thailand, recruiting semi-immune volunteers from endemic areas representative of target populations for vaccine deployment. We will draw on the participating institutions' expertise in clinical malaria, immunology, entomology, parasitology, volunteer infection studies, and vaccine development. We plan to develop vivax controlled human vivax malaria infection models able to test protective efficacy of the pre-erythocytic and blood stage vivax malaria vaccines currently in development. During this programme we plan to conduct six volunteer infection studies, determine immunological correlates of protection, and test four vaccine candidates. The programme will lay the groundwork for developing models to test future transmission blocking vaccines and new anti-relapse drugs for radical cure. The volunteer infection studies will be accompanied by a programme of social science and empirical ethics research to assess their acceptability and the understanding of volunteers, patients, researchers and policy-makers.

View the original record at the funder ↗

Researchers

Nicholas Day (EPMC Awardee)

Related Research

Grants with similar aims, by meaning.

Development of Effective Vaccines against Multiple Lifecycle Stages of Plasmodium vivax malaria
Serological testing and treatment for p. Vivax: From a cluster-randomised trial in ethiopia and madagascar to a mobile-technology supported intervention
Novel tools and approaches for safer and more effective treatment of Plasmodium vivax malaria
Optimising a High Efficacy Plasmodium vivax Malaria Vaccine
BIO-006: A clinical study to assess the safety and feasibility of relapsing P. vivax controlled human malaria infection through experimental sporozoite infection of healthy malaria-na ve UK adults, and to characterise parasite growth and immune responses to primary and relapsing P. vivax infection

Original classification

Controlled Human Infection Models

Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.