Study of Safety and Effectiveness of Intravenous Immunization With PfSPZ Vaccine in Healthy African Adults - Vaccine Efficacy and Placebo Cohorts

A Phase 1 randomized, double blind, placebo-controlled trial to assess the safety and immunogenicity of intravenous (IV) administration of cryopreserved radiation attenuated Pf sporozoites (SPZ) and the vaccine efficacy (VE) against naturally occurring malaria infection in healthy African adults. After establishing safety of PfSPZ Vaccine in a pilot group (N=12), subjects received either 5 doses of PfSPZ Vaccine (N=48) or normal saline (NS) placebo (N=48). VE was assessed by detection of Pf by thick blood smear (TBS) for 24 weeks after last dose of vaccine or NS.