Clinical Research Fellow Andrew Duncan Presents Latest BIO-008 Findings at the 7th International Conference on Malaria Immunology and Elimination
Clinical Research Fellow Andrew Duncan recently presented the latest findings from the BIO-006 study at the 7th International Conference on Malaria Immunology and Elimination (MIE 2026). The conference, organised by United Scientific Group, brings together an international network of scientists to discuss the latest research, emerging perspectives, technological advances, and scientific developments in malaria immunology and elimination, with a particular focus on new approaches to controlling malaria infection worldwide.
A Human Challenge Model of Relapsing Plasmodium vivax Malaria
Plasmodium vivax is a major cause of malaria globally and approximately 80% of cases are due to relapse infections. The mechanisms behind malaria relapses are poorly understood. Novel preventative and curative therapies for relapsing P. vivax malaria will be key in the pursuit of malaria elimination. We have developed a Controlled Human Malaria Infection (CHMI) model of relapsing P. vivax. We recruited healthy malaria-naïve adults in Oxford, UK, with extensive CYP2D6 metaboliser phenotype and normal G6PD screen. Five eligible participants underwent P. vivax malaria challenge (using a well-characterised clonal isolate, “PvW1”) administered by five infectious bites of Anopheles stephensi mosquitoes at Radboud University Medical Center, Nijmegen, Netherlands. All participants developed blood-stage P. vivax parasitaemia (qPCR > 500 genome copies/ml) 8 – 10 days following malaria challenge. Primary infection was cleared with artemether lumefantrine (AL) without safety concern. Participants entered a six-month relapse follow-up period. They attended a fortnightly qPCR monitoring clinic and had access to an on-call study doctor for assessment of possible malaria symptoms. Relapse infections were treated with AL. Definitive anti-malarial treatment (including primaquine 0.5 mg/kg/day for 14 days) was administered at the end of the follow-up period. All five participants experienced at least one relapse P. vivax infection (qPCR > 500 genome copies/mL); two participants experienced a second relapse infection. Solicited adverse events related to P. vivax infection were mild or moderate during primary and relapse infections. This study establishes the P. vivax sporozoite CHMI model in Europe, provides a platform for future intervention studies, and an opportunity to improve our understanding of relapsing P. vivax malaria.
A preprint describing the study in full is available on medRxiv: Duncan A et al. A Controlled Human Malaria Infection model for relapsing Plasmodium vivax.