Safety and immunogenicity in age de-escalation of PfSPZ Vaccine in Tanzania

The present trial will evaluate safety and tolerability as well as the vaccine-induced humoral and cellular immune responses in healthy Tanzanian adults, adolescents, children, and infants who receive doses of 1.8x10^6, 9.0x10^5, 4.5x10^5 or 2.7x10^5 PfSPZ of PfSPZ Vaccine by direct venous inoculation (DVI),compared with control groups receiving normal saline (NS) placebo by DVI. In addition, as an exploratory objective, controlled human malaria infection (CHMI) will be used to assess efficacy in adults three weeks following immunization.