Safety and Immunogenicity of the Malaria Vaccine, R21/MatrixM, in Healthy Thai Adults

R21/Matrix-M is the standard formulation of the vaccine (Once prepared, a standard dose of R21/Matrix-M contains approximately 5 µg of R21 antigen, in 0.5 mL of liquid adjuvant containing 50 µg MatrixM). The reconstituted vaccine will be administered by slow IM injection on Day 0 at Study Months 0, 1 and 2.

Dihydroartemisinin/piperaquine tablets for adult patients each contain 40 mg dihydroartemisinin and 320 mg piperaquine with a therapeutic dose range between 2-10 mg/kg/day dihydroartemisinin and 16-26 mg/kg/dose piperaquine. Participants will receive three rounds of antimalarial drugs - each round starting on the day of vaccination (Day 0) at Study Months 0, 1 and 2. Each round consists of three daily doses of co-formulated dihydroartemisinin/piperaquine on Day 0, 1, and 2.

Each participant will receive a single low dose primaquine on the day of vaccination (Day 0) at Month 0, Month 1, and Month 2. One single low dose primaquine of approximately 0.25 mg/kg will be administered.