This is a single center, randomized and controlled human study to optimize controlled human malaria infection (CHMI) administered by direct venous inoculation (DVI). 36 healthy adults aged between 18 and 45 years, will be randomized to one of five groups and will be inoculated with PfSPZ Challenge DVI. Participation duration is estimated to be 2 months, while the study duration is planned to be 4 months. The primary objective of this study is to assess the safety and reactogenicity of PfSPZ Challenge administered by DVI using 7G8 and NF54 P. falciparum strains.