This is a phase 1b, multicenter, randomized, placebo-controlled, observer-blinded, dose-escalation study, assessing the safety, tolerability, and immunogenicity of a three-dose regimen, spaced four weeks apart, given intramuscularly in healthy adults (20-59 years old). Three different dose formulations of the study product with varying antigen contents will be investigated. A total of 120 eligible participants will be recruited in 3 sequential cohorts (A, B, and C) in Burkina Faso (N=60) and in Madagascar (N=60), as shown in the Table 1, below. Cohort A will receive the low-dose antigen formulation (10 µg) or placebo, Cohort B will receive the medium-dose antigen formulation (30 µg) or placebo, and Cohort C will receive the high-dose antigen formulation (100 µg) or placebo; all antigens with 5 μg adjuvant (GLA-SE). In each cohort, volunteers will be randomized in a blinded manner into one of two arms, candidate vaccine or placebo, by a 3:1 ratio. A subset of five out of 20 subjects in each cohort will be sampled by convenience to enable us to further characterize the immune response using the peripheral blood mononuclear cells (PBMC).~To ensure that the study participants at enrollment do not have any active schistosomiasis or helminth infection and are schistosomiasis egg-negative, pre-screening activities including schistosomiasis treatment will be carried out in potential study participants prior to enrollment. Potential study participants will be identified in the catchment population and will be offered anti-helminth treatment using praziquantel (PZQ) and Albendazole (ABZ) as per local guidelines at study site. The pre-screening visit will be conducted 6-8 weeks before the screening visit. The last dose of PZQ/ABZ will be administered at least 5 weeks prior to the first dose of study product.~The Primary objective is to evaluate the safety and tolerability of 3 different dose formulations (low dose, medium dose, and high dose) of SchistoShield® vaccine given intramuscularly on D0, D28 and D56 to healthy participants 20 to 59 years of age in Burkina Faso and Madagascar.~The Secondary objective is to evaluate the immunogenicity of 3 different dose formulations (low dose, medium dose, and high dose) of SchistoShield® vaccine 28 days post-vaccination on D28, D56, and D84 as compared with the baseline and with those who received placebo.~The Exploratory objective is to describe the antigen-specific B- and T-cell responses, memory responses, and innate and adaptive immune signatures from samples collected at specified timepoints.
The goal of this phase 1b, multicenter, randomized, placebo-controlled, observer-blinded, dose-escalation study is to assess the safety, tolerability, and immunogenicity of a three-dose regimen, spaced four weeks apart, given intramuscularly in healthy adults (20-59 years old). Three different dose formulations of the study product with varying antigen contents will be investigated.~A total of 120 eligible participants will be recruited in 3 sequential cohorts (A, B, and C) in Burkina Faso (N=60) and in Madagascar (N=60). Cohort A will receive the low-dose antigen formulation (10 µg) or placebo, Cohort B will receive the medium-dose antigen formulation (30 µg) or placebo, and Cohort C will receive the high-dose antigen formulation (100 µg) or placebo; all antigens with 5 μg adjuvant (GLA-SE). In each cohort, volunteers will be randomized in a blinded manner into one of two arms, candidate vaccine or placebo, by a 3:1 ratio. A subset of five out of 20 subjects in each cohort will be sampled by convenience to enable us to further characterize the immune response using the peripheral blood mononuclear cells (PBMC). The Primary Objective of the study is to evaluate the safety and tolerability of 3 different dose formulations (low dose, medium dose, and high dose) of SchistoShield® vaccine given intramuscularly on D0, D28 and D56 to healthy participants 2018 to 59 years of age in Burkina Faso and Madagascar.