Evaluate the Safety, Immunogenicity and Potential Efficacy of an rVSV-SARS-CoV-2-S Vaccine

In the Phase I, healthy adult volunteers will be randomly allocated to one of the four treatment groups to receive a single administration (prime) of IIBR-100 at low, mid or high dose or saline or two administrations (prime-boost) of IIBR-100 at low dose, or saline, 28 days apart. During Phase I, dosing of prime will proceed in a sequential fashion followed by a safety review committee and DSMB to consider expansion to include the rest of the group and escalation to the next groups. Only Groups that demonstrate acceptable safety profile, immunogenicity and potential efficacy will be included in the Phase II operation. In both phases, the subjects will receive an intramuscular injection of the IIBR-100 consisted of 1ml replicating viral rVSV SARS-CoV-2-S vaccine or placebo consisted of 1ml of 0.9% saline. Dosing will be performed at Day 0 and Day 28 (for allocated to prime-boost treatment groups) in the deltoid muscle and will be followed through 12 months post last vaccination. Follow-up visits for subjects administered with the single administration (prime) or placebo will occur at 1, 2 and 4 weeks as well as 2, 3, 6, 9 and 12 months after dosing. Follow up visits for subjects administered with two administrations (prime-boost) or placebo will occur at 1, 2 and 4 weeks post each vaccination as well as at 2, 3, 6, 9 and 12 months after the second vaccination. Reactogenicity will be measured by the occurrence of solicited injection site and systemic reactions from the time of each dosing through 7 days post each dosing. Unsolicited non-serious safety events will be collected from the time of each dosing through 28 days post each dosing. Serious safety events, new-onset chronic medical conditions and medically attended safety events will be collected through 12 months after the last dosing.