VBI-2901a is an investigational trivalent COVID-19 vaccine candidate that comprises enveloped virus-like particles (eVLPs) expressing the spike proteins of the beta-coronaviruses SARS-CoV-2, SARS-CoV-1 and MERS-CoV. The study will enroll participants 18 to 64 years of age who have previously received two or more vaccinations with a licensed COVID-19 vaccine(s) and will test two intramuscular doses of VBI-2901a containing 5 µg or 10 µg of spike protein and one dose of VBI-2901a containing 10 µg of spike protein. VBI-2901a eVLPs are formulated with 0.33 mg of aluminum phosphate (alum) adjuvant per dose. VBI-2901a is designed to induce neutralizing antibody and cell-mediated immune responses against multiple coronavirus respiratory disease strains and variants of SARS-CoV-2.~This is a randomized, open-label Phase 1 study. The study will enroll adults, aged 18 to 64 years, who are healthy or in stable health; had previously received two or more vaccinations with a 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 99 participants will be randomized at a 1:1:1 ratio to the following study groups:~Group G1: 33 participants to receive two doses of VBI-2901a at 5 µg per dose at Day 1 and Day 56.~Group G2: 33 participants to receive two doses of VBI-2901a at 10 µg per dose at Day 1 and Day 56.~Group G3: 33 participants to receive one dose of VBI-2901a at 10 µg per dose at Day 1.~The total study duration for each vaccinated subject is 48 weeks (336 days) after administration of the first dose of study vaccine. During the study, the participant will make 9 visits to the study site, including the screening visit.~The objective of the study is to select the optimal dose level (5 µg or 10 µg) and number of doses (1 or 2 doses) of trivalent coronavirus vaccine candidate VBI-2901a 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 SARS-CoV-2 ancestral (Wuhan) strain, selected SARS-CoV-2 variants, SARS-CoV-1 and MERS-CoV.
VBI-2901a 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, SARS-CoV-2 variants (such as Beta, Delta and Omicron) and other related coronaviruses that could emerge in the future.~The Phase 1 study will be an open-label comparison of two intramuscular doses of VBI-2901a at 5 µg or 10 µg per dose or one dose of VBI-2901a at 10 µg per dose in adults 18 to 64 years of age who had previously received two or more vaccinations with licensed COVID-19 vaccines. The purpose of the study is to test the safety of VBI-2901a and to know more about its ability to boost immune response against SARS-CoV-2 (the virus that causes COVID-19 disease) and two other related coronaviruses SARS-CoV-1 and MERS-CoV.