Immunization with full-length Plasmodium falciparum merozoite surface protein 1 is safe and elicits functional cytophilic antibodies in a randomized first-in-human trial

<p>This file contains the original data underpinning the article in npj vaccines, in which we describe a phase 1 safety and immunogenicty study on the malaria vaccine candidate MSP1 in humans. The abstract of the article follows:</p> <p>A vaccine remains a priority in the global fight against malaria. Here, we report on a single-center, randomized, double-blind, placebo and adjuvant-controlled, dose escalation phase 1a safety and immunogenicity clinical trial of full-length <i>Plasmodium falciparum</i> merozoite surface protein 1 (MSP1) in combination with GLA-SE adjuvant. 32 healthy volunteers were vaccinated at least three times with MSP1 plus adjuvant, adjuvant alone or placebo (24:4:4) to evaluate the safety and immunogenicity. MSP1 was safe, well tolerated and immunogenic, with all vaccinees sero-converting independent of the dose. The MSP1-specific IgG and IgM titers persisted above levels found in malaria semi-immune humans for at least six months after the last immunization. The antibodies were variant- and strain-transcending and stimulated respiratory activity in granulocytes. Furthermore, full-length MSP1 induced memory T-cells. Our findings encourage challenge studies as the next step to evaluate the efficacy of full-length MSP1 as a vaccine candidate against falciparum malaria (EudraCT 2016-002463-33).</p>