VBI-2901e is an investigational trivalent COVID-19 vaccine candidate that comprises enveloped virus-like particles (eVLPs) expressing the spike proteins of the betacoronaviruses SARS-CoV-2, SARS-CoV-1 and MERS-CoV and the adjuvants aluminum phosphate and E6020 (a toll-like receptor 4 agonist). The study will enroll participants 18 to 40 years of age who have previously received two or more vaccinations with licensed COVID-19 vaccine(s) and will test one or two intramuscular doses of VBI-2901e containing 5 μg of SARS-CoV-2 spike protein, 165 µg of aluminum phosphate and 1, 3 or 10 µg of E6020. VBI-2901e is designed to induce neutralizing antibody and cell-mediated immune responses against multiple coronavirus respiratory disease strains and variants/subvariants of SARS-CoV-2.~This is a randomized, open-label adjuvant dose-escalation study. The study will enroll healthy adults, aged 18 to 40 years of age, who had previously received two or more vaccinations with licensed COVID-19 vaccine(s), with the final dose administered a minimum of 6 months (24 weeks) prior to enrollment; have a negative PCR or rapid antigen SARS-CoV-2 test at screening; and have met all other eligibility criteria. Participants with a history of mild COVID-19 illness are eligible if they fully recovered a minimum of 6 months (24 weeks) prior to enrollment.~A total of 60 participants will be enrolled in the study. Study groups will be enrolled sequentially in an E6020 dose-escalating fashion starting with 20 participants to receive VBI-2901e with 1 µg of E6020 (Group G1), followed by 20 participants to receive VBI-2901e with 3 µg of E6020 (Group G2) and 20 participants to receive VBI-2901e with 10 µg E6020 (Group G3). Within each study group, participants will be randomized at a 1:1 ratio to receive one or two doses of VBI-2901e.~Group G1~Subgroup G1-A: 10 participants to receive VBI-2901e at 5 µg with 1 µg E6020 per dose on Day 1.~Subgroup G1-B: 10 participants to receive VBI-2901e at 5 µg with 1 µg E6020 per dose on Day 1 and Day 28.~Group G2~Subgroup G2-A: 10 participants to receive VBI-2901e at 5 µg with 3 µg E6020 per dose on Day 1.~Subgroup G2-B: 10 participants to receive VBI-2901e at 5 µg with 3 µg E6020 per dose on Day 1 and Day 28.~Group G3~Subgroup G3-A: 10 participants to receive VBI-2901e at 5 µg with 10 µg E6020 per dose on Day 1.~Subgroup G3-B: 10 participants to receive VBI-2901e at 5 µg with 10 µg E6020 per dose on Day 1 and Day 28.~The objective of the study is to select the optimal dose level of E6020 adjuvant (1, 3 or 10 μg) and number of doses (1 or 2 doses) of trivalent coronavirus vaccine candidate VBI-2901e in individuals who had been vaccinated against COVID-19 previously. To achieve this objective, the study will evaluate outcomes including safety and tolerability as well as antibody and T cell immune responses against the original SARS-CoV-2 ancestral strain, selected SARS-CoV-2 variants, SARS-CoV-1 and MERS-CoV.
VBI-2901e is an investigational vaccine candidate that uses enveloped virus-like particles (eVLPs) to express the spike proteins of three coronaviruses: SARS-CoV-2 (the virus that causes COVID-19 disease), SARS-CoV-1 and MERS-CoV. The trivalent vaccine candidate is designed to induce neutralizing antibody and cell-mediated immune responses against the spike protein of the original strain of SARS-CoV-2 coronavirus, variants and subvariants of SARS-CoV-2 (such as Beta, Delta and Omicron BA.5) and other related coronaviruses that could emerge in the future. VBI-2901e contains two adjuvants: aluminum phosphate and E6020. The role of the adjuvants is to create a stronger immune response to the vaccine.~This Phase 1 study will be an open-label study of VBI-2901e comparing three dose levels of the E6020 adjuvant component (1, 3, or 10 µg per dose) in adults 18 to 40 years of age who had previously received two or more vaccinations with licensed COVID-19 vaccine(s). VBI-2901e at each dose level of E6020 will be administered as either a single dose or two-dose regimen. The purpose of the study is to test the safety of VBI-2901e and to learn more about its ability to boost immune responses against SARS-CoV-2 and the two related coronaviruses SARS-CoV-1 and MERS-CoV.