The aim of this collaboration is to determine how phagocytosis may be associated with protection to controlled human malaria infection (CHMI) challenge and/or the type of vaccine regimen.
Subjects in the MAL068  safety, immunogenicity, and efficacy clinical trial who were protected from a CHMI challenge, had polyclonal antibody responses with lower phagocytic activity. In the  MAL071 safety, immunogenicity, and efficacy clinical trial, subjects who received the delayed fractional dose of RTS,S/AS01 had antibody responses less capable of activating phagocytosis, as compared to subjects who received the standard vaccine regimen. To build on our current understandings of antibody-mediated phagocytosis as a potential correlate of protection for RTS,S in similar studies conducted on MAL068 and MAL071 samples, this collaboration will evaluate serum collected from subjects vaccinated with RTS,S/AS01 in two clinical trials (VAC055 and VAC059) conducted at The University of Oxford.