PfSPZ Challenge (7G8)

PfSPZ Challenge (7G8) is a biologic product consisting of aseptic, purified, cryopreserved sporozoites of the Plasmodium falciparum 7G8 clone. It is used for controlled human malaria infection (CHMI) studies to assess the efficacy of antimalarial vaccines and drugs. The 7G8 strain originates from Brazil and is genetically distant from the West African NF54 strain commonly used in vaccine development, making it a stringent surrogate for field strains in Africa. The mechanism involves direct venous inoculation of viable P. falciparum sporozoites to induce malaria infection under controlled conditions in nonimmune adults. This enables rigorous evaluation of vaccine-induced protection or drug efficacy by monitoring time to parasitemia and infectivity rates[1][3][4]. Developed primarily as a research tool rather than a therapeutic or preventive intervention itself, its use streamlines vaccine development by providing conservative estimates of protective efficacy before large-scale field trials[2][4].

Other names

Plasmodium falciparum 7G8 sporozoites