Controlled human malaria infection of healthy adults with lifelong malaria exposure to assess safety, immunogenicity, and efficacy of the asexual blood stage malaria vaccine candidate GMZ2

TY - JOUR

T1 - Controlled human malaria infection of healthy adults with lifelong malaria exposure to assess safety, immunogenicity, and efficacy of the asexual blood stage malaria vaccine candidate GMZ2

AU - Dejon-Agobe, Jean Claude

AU - Ateba-Ngoa, Ulysse

AU - Lalremruata, Albert

AU - Homoet, Andreas

AU - Engelhorn, Julie

AU - Nouatin, Odilon Paterne

AU - Edoa, Jean Ronald

AU - Fernandes, José F

AU - Esen, Meral

AU - Mouwenda, Yoanne Darelle

AU - Betouke Ongwe, Eunice M

AU - Massinga-Loembe, Marguerite

AU - Hoffman, Stephen L

AU - Sim, B Kim Lee

AU - Theisen, Michael

AU - Kremsner, Peter G

AU - Adegnika, Ayôla A

AU - Lell, Bertrand

AU - Mordmüller, Benjamin

N1 - © The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: [email protected].

PY - 2019/9/27

Y1 - 2019/9/27

N2 - BACKGROUND: GMZ2 is a recombinant malaria vaccine inducing immune responses against Plasmodium falciparum (Pf) merozoite surface protein-3 and glutamate-rich protein. We used standardized controlled human malaria infection (CHMI) to assess the efficacy of this asexual blood-stage vaccine.METHODS: We vaccinated 50 healthy, adult volunteers with lifelong exposure to Pf 3 times, at 4-week intervals, with 30 or 100 µg GMZ2 formulated in CAF01, a liposome-based adjuvant; 100 µg GMZ2, formulated in Alhydrogel; or a control vaccine (Verorab). Approximately 13 weeks after the last vaccination, 35/50 volunteers underwent CHMI by direct venous inoculation of 3200 Pf sporozoites (Sanaria® PfSPZ Challenge).RESULTS: Adverse events were similarly distributed between GMZ2 and control vaccinees. Baseline-corrected anti-GMZ2 antibody concentrations 4 weeks after the last vaccination were higher in all 3 GMZ2-vaccinated arms, compared to the control group. All GMZ2 formulations induced similar antibody levels. CHMI resulted in 29/34 (85%) volunteers with Pf parasitemia and 15/34 (44%) with malaria (parasitemia and symptoms). The proportion of participants with malaria (2/5 control, 6/10 GMZ2-Alhydrogel, 2/8 30 µg GMZ2-CAF01, and 5/11 100 µg GMZ2-CAF01) and the time it took them to develop malaria were similar in all groups. Baseline, vaccine-specific antibody concentrations were associated with protection against malaria.CONCLUSIONS: GMZ2 is well tolerated and immunogenic in lifelong-Pf-exposed adults from Gabon, with similar antibody responses regardless of formulation. CHMI showed no protective effect of prior vaccination with GMZ2, although baseline, vaccine-specific antibody concentrations were associated with protection. CHMI with the PfSPZ Challenge is a potent new tool to validate asexual, blood-stage malaria vaccines in Africa.CLINICAL TRIALS REGISTRATION: Pan-African Clinical Trials: PACTR201503001038304.

AB - BACKGROUND: GMZ2 is a recombinant malaria vaccine inducing immune responses against Plasmodium falciparum (Pf) merozoite surface protein-3 and glutamate-rich protein. We used standardized controlled human malaria infection (CHMI) to assess the efficacy of this asexual blood-stage vaccine.METHODS: We vaccinated 50 healthy, adult volunteers with lifelong exposure to Pf 3 times, at 4-week intervals, with 30 or 100 µg GMZ2 formulated in CAF01, a liposome-based adjuvant; 100 µg GMZ2, formulated in Alhydrogel; or a control vaccine (Verorab). Approximately 13 weeks after the last vaccination, 35/50 volunteers underwent CHMI by direct venous inoculation of 3200 Pf sporozoites (Sanaria® PfSPZ Challenge).RESULTS: Adverse events were similarly distributed between GMZ2 and control vaccinees. Baseline-corrected anti-GMZ2 antibody concentrations 4 weeks after the last vaccination were higher in all 3 GMZ2-vaccinated arms, compared to the control group. All GMZ2 formulations induced similar antibody levels. CHMI resulted in 29/34 (85%) volunteers with Pf parasitemia and 15/34 (44%) with malaria (parasitemia and symptoms). The proportion of participants with malaria (2/5 control, 6/10 GMZ2-Alhydrogel, 2/8 30 µg GMZ2-CAF01, and 5/11 100 µg GMZ2-CAF01) and the time it took them to develop malaria were similar in all groups. Baseline, vaccine-specific antibody concentrations were associated with protection against malaria.CONCLUSIONS: GMZ2 is well tolerated and immunogenic in lifelong-Pf-exposed adults from Gabon, with similar antibody responses regardless of formulation. CHMI showed no protective effect of prior vaccination with GMZ2, although baseline, vaccine-specific antibody concentrations were associated with protection. CHMI with the PfSPZ Challenge is a potent new tool to validate asexual, blood-stage malaria vaccines in Africa.CLINICAL TRIALS REGISTRATION: Pan-African Clinical Trials: PACTR201503001038304.

U2 - 10.1093/cid/ciy1087

DO - 10.1093/cid/ciy1087

M3 - Journal article

C2 - 30561539

SN - 1058-4838

VL - 69

SP - 1377

EP - 1384

JO - Clinical Infectious Diseases

JF - Clinical Infectious Diseases

IS - 8

ER -