Vaccine Safety and Placebo Groups Arm 1C & 1D with CHMI: Safety, Immunogenicity, and Protective Efficacy of Radiation Attenuated Plasmodium falciparum NF54

Three injections by DVI on days 1, 57 and 113 of 1.8x10^6 PfSPZ of PfSPZ Vaccine to each of 30 subjects – 15 pretreated with artesunate amodiaquine and 15 not pretreated. Subjects underwent CHMI via PfSPZ Challenge DVI approximately 21 days following the third injection (vaccination #3) in addition to 15 unvaccinated subjects to serve as infectivity controls. Subjects were followed for 28 days after CHMI. Assessment of parasitemia and malaria related clinical symptoms began on Day 6 post CHMI and continued daily until the first microscopic detection of parasitemia (positive blood smear). Subjects were seen in the clinic once daily until a positive blood smear was obtained or until the 27th day post CHMI. Standard treatment with Coartem (artemether-lumefantrine) was initiated upon diagnosis of P. falciparum. All subjects in this group had the option of receiving a booster dose of PfSPZ Vaccine prior to transmission season in 2016.