Partner study description
This study is a phase I clinical trial to evaluate the safety of repeated intravenous (IV) immunizations with irradiated Plasmodium falciparum sporozoites (PfSPZ) in African adults. In collaboration with Sanaria and the MRTC in Bamako, the Laboratory of Malaria Immunology and Vaccinology at NIH recruited randomly assigned healthy adults from the area around Doneguebougou, Mali to receive test product or control. Vaccinees received five inoculations of PfSPZ, or placebo, by IV injection, and were monitored for natural infection during the ensuing transmission season. In addition to the primary objective of evaluating safety, this study assessed the protective efficacy of the vaccine against natural infections, related host responses to protection, and evaluated transmission blocking potential. The study also planned to perform whole-genome sequencing of parasites isolated from the peripheral blood of participants who become infected. It was planned that the genotypes provided by MalariaGEN would be used to answer several specific questions: (1) Are parasites from test patients more diverged from the vaccine strain (NF54) than those from the control group? (2) Is there evidence of selective pressure in specific genomic loci that might inform selection of (or validate) pre-erythrocytic vaccine antigens? (3) Is the genetic diversity of parasite populations different amongst the treatment groups?