COVID-19 vaccine trials

VIDO is advancing two subunit vaccine candidates for COVID-19 (COVAC-1 and COVAC-2). Subunit vaccines contain purified viral proteins that are not infectious. VIDO’s vaccine candidates use the same antigen, but different adjuvants. An adjuvant is a compound that is added to a vaccine to help the vaccine produce a better immune response.

Vaccines undergo Phase 1, Phase 2 and Phase 3 clinical trials. These trials help to demonstrate safety (Phase 1), immunogenicity (Phase 2) and effectiveness (Phase 3), before a vaccine can receive regulatory approval and be recommended for wide-spread use. In Canada, approval is granted by Health Canada through the Biologic and Radiopharmaceutical Drugs Directorate (BRDD), and recommendation from the National Advisory Committee on Immunization (NACI).  

What is the status of your COVID-19 vaccines?

COVAC-2 is currently in Phase 2 testing in Uganda. Study enrollment is complete with 150 participants. Interim safety and immunogenicity data is expected by summer 2023. COVAC-2 is also undergoing clinical testing as a “booster” vaccine at four Canadian sites for participants who have received at least two doses of authorized COVID-19 vaccine four months earlier.

COVAC-1 is in clinical testing as a “booster” vaccine. The Phase 1 clinical trial is at four Canadian sites.

More information on the ongoing clinical trials can be found at

  • NCT05209009 (COVAC-2 Phase 2 in Uganda) - fully enrolled 
  • NCT05226702 (COVAC-2 booster study in Burlington, Halifax, Saskatoon, and Toronto) - fully enrolled 
  • NCT05693272 (COVAC-1 Phase 1 study in Joliette, Quebec City, Sherbrooke, and Victoriaville)

VIDO has also received funding from the Coalition for Epidemic Preparedness Innovation, to develop a broadly protective coronavirus vaccine that could offer protection against SARS-CoV-2 variants and other betacoronaviruses (e.g., SARS-CoV-1 and MERS-CoV). CEPI is a global alliance that finances and coordinates the development of new vaccines to prevent and contain infectious disease epidemics.