A Clinical Trial of COVAC-1, a COVID-19 Vaccine, in Generally Healthy Adults

VIDO has developed a vaccine called COVAC-1. The 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 an adjuvant called TriAdj. An adjuvant is a compound that is added to a vaccine to help the vaccine produce a better immune response. The TriAdj adjuvant is made up of three components (a toll-like receptor agonist polyI:C, an immunostimulatory host defense protein HDP IDR-1002 and a polyphosphazene carrier system, PCEP). The three components work together to improve the body's response to the S1 protein. The COVAC-1 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 or reduce the severity of 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. Phase 1 is a multi-centred, multi-national trial of the COVAC-1 vaccine to be completed in Canada and Brazil. It will be a randomized, observer-blinded, and placebo-controlled study to assess the safety and immunogenicity of two dosing levels (25 and 50 µg S1 protein) administered twice (4 weeks apart) in healthy adults 18 through 54 years of age (Arm 1a) and 55 years of age and older (Arm 1b). Enrolment and vaccination of participants will be staggered over time based on vaccine dose. Study participants aged 18 to 54 and those \>55 years of age will commence in parallel at the starting dose of 25 ug and after approval by Sponsor based upon recommendations from the Data Safety Monitoring Board (DSMB), new study participants will be allowed to receive the higher dose of 50 ug. Approval will also be sought from Sponsor, based on recommendations provided by the DSMB, to proceed with the second dose in each dosing and age group. W