A Clinical Trial to Study the COVAC-1 Booster Dose in Generally Healthy Adults

VIDO has developed a vaccine called COVAC-1. The COVAC-1 study vaccine contains a portion of the SARS-CoV-2 spike protein, called S1. The spike protein is the part of the virus that is responsible for attaching to the surface of host cells. COVAC-1 contains a TriAdj adjuvant. An adjuvant is a compound that is added to a vaccine to help the vaccine produce a better immune response. The vaccine is expected to stimulate the body to make antibodies against the S1 protein. The antibodies will recognize the viral spike protein if the body is exposed to the virus and prevent COVID-19 illness. In animal studies, the immune response generated by the COVAC-1 vaccine was able to protect the vaccinated animals against a severe SARS-CoV-2 infection. The COVAC-005 Study is a Phase I, multi-centre trial of a SARS-CoV-2 vaccine booster. This is a randomized, observer-blinded, and placebo-controlled study to assess the safety and immunogenicity of COVAC-1 booster dose administered once in generally healthy adults 18-65 years of age who have received a minimum of 2 doses of an authorized COVID-19 vaccine at least 4 months prior to Day 0. The study will follow a dose-escalation design to test the safety and immunogenicity of three dosage levels (10, 25 and 50 µg). In each dose escalation group participants will be randomized in a 3:1 ratio, to receive either the investigational product or a placebo, respectively. Stratification will be according to the Investigational product dose received. Sub-analysis will be completed in two age groups, 18-54 and 55-65 years. Study participants will be initially randomized to the lowest dose of 10 µg or placebo. After approval by the Sponsor and based on the recommendations from the DSMB following the Day 7 safety analysis, new study participants will be allowed to be randomized in the higher dose escalation group of 25 µg. Approval will also be sought from the Sponsor, based upon the DSMB recommendation, to proceed with the higher dose of 50 µg. Within each dose escalation group of 16 participants (12 active vaccine recipients, and 4 placebo recipients) it is proposed to randomize a first cohort of 4 participants, including at least 3 active vaccine recipients, and pending no holding rule is met after 48 hours, as determined by the post-injection phone call, the remaining 12 participants within that dose escalation group will be randomized.