Need Help?

Study of Controlled Human Malaria Infections to Evaluate Protection After Intravenous or Intramuscular Administration of PfSPZ Vaccine in Malaria-Naive Adults

The study was performed to evaluate whole-blood transcriptomic profiles via RNA-seq before, during, and after immunization with the PfSPZ Vaccine in malaria-naïve, health adults enrolled in VRC 314 (NCT02015091). VRC 314 was designed as an open-label evaluation of the safety, tolerability, immunogenicity, and protective efficacy of the PfSPZ Vaccine. This study was designed to substantiate the initial results with the IV vaccination route for protection against CHMI that was observed in VRC 312 (NCT01441167). Based on the potential importance of dose and schedule in optimizing sustained immunity with this vaccine, an increase in PfSPZ IV dosage on schedules of 3 to 5 vaccinations was evaluated for protection against CHMI conducted early (about 3 weeks) and late (about 24 weeks) after completion of vaccinations. To assess if a higher dose given by another route confers protection, one group received PfSPZ IM, with half of the amount administered in each arm on a schedule with 4 vaccination. The primary objectives of the study were related to the safety and tolerability of vaccinations by the IV and IM routes of administration and protection against Plasmodium falciparum (Pf) challenge performed via a well-established CHMI procedure early (2-4 weeks) after completing schedules of 3 to 5 vaccinations. The secondary objective was related to the durability of protection at 20-26 weeks after the last vaccination, and exploratory objectives were related to the immunogenicity of the PfSPZ Vaccine and identifying potential immune correlates of protection. To further determine potential molecular correlates of immunogenicity and/or protection, RNA-seq was performed on whole blood collected from subjects in all dose groups at time points before, during, and after immunization.