 Once malaria infections are detected by 18S qPCR positive day of treatment 1 DT1, groups 1 and 2 will be treated with a course of subcurative sulfadoxine-pyrimethamine SP SP low, 500mg25mg. Groups 3 and 4 will receive piperaquine Pip in a low-dose Pip low, 480 mg. After DT1, volunteers will receive a curative treatment DT2 when a recrudescence of asexual parasitaemia occurs or on day 21 post challenge infection, whichever comes first. Volunteers in group 1 SP lowSP high will be treated with sulfadoxine-pyrimethamine 1000mg50mg and group 2 SP lowPip high with piperaquine 960mg. Volunteers in group 3 Pip lowPip high will be treated with piperaquine 960mg and group 4 Pip lowSP high with sulfadoxine-pyrimethamine 1000mg50mg. To ensure the radical clearance of all parasite stages, all volunteers will receive a final treatment ET according to national guidelines with atovaquoneproguanil Malarone on day 42. Daily blood samples will allow detailed quantification of gametocytes, gametocyte sex ratio and ex vivo assessments of gametocyte fitness. 