1. Multifunctional IgG/IgM antibodies and cellular cytotoxicity are elicited by the full-length MSP1 SumayaVac-1 malaria vaccine.
- Author
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Rosenkranz, Micha, Fürle, Kristin, Hibbert, Julia, Ulmer, Anne, Ali, Arin, Giese, Thomas, Blank, Antje, Haefeli, Walter E., Böhnlein, Ernst, Lanzer, Michael, and Thomson-Luque, Richard
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MALARIA vaccines ,IMMUNOGLOBULINS ,IMMUNOLOGIC memory ,HUMORAL immunity ,IMMUNOGLOBULIN G ,FC receptors ,REACTIVE oxygen species ,COMPLEMENT receptors - Abstract
Radical control of malaria likely requires a vaccine that targets both the asymptomatic liver stages and the disease-causing blood stages of the human malaria parasite Plasmodium falciparum. While substantial progress has been made towards liver stage vaccines, the development of a blood stage vaccine is lagging behind. We have recently conducted a first-in-human clinical trial to evaluate the safety and immunogenicity of the recombinant, full-length merozoite surface protein 1 (MSP1
FL ) formulated with GLA-SE as adjuvant. Here, we show that the vaccine, termed SumayaVac-1, elicited both a humoral and cellular immune response as well as a recall T cell memory. The induced IgG and IgM antibodies were able to stimulate various Fc-mediated effector mechanisms associated with protection against malaria, including phagocytosis, release of reactive oxygen species, production of IFN-γ as well as complement activation and fixation. The multifunctional activity of the humoral immune response remained for at least 6 months after vaccination and was comparable to that of naturally acquired anti-MSP1 antibodies from semi-immune adults from Kenya. We further present evidence of SumayaVac-1 eliciting a recallable cellular cytotoxicity by IFN-γ producing CD8+ T cells. Our study revitalizes MSP1FL as a relevant blood stage vaccine candidate and warrants further evaluation of SumayaVac-1 in a phase II efficacy trial. [ABSTRACT FROM AUTHOR]- Published
- 2023
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