VIDO Updates Progress on Two Subunit Candidate COVID-19 Vaccines

The Director of Vaccine Development with the Vaccine and Infectious Disease Organization says VIDO is advancing two COVID-19 vaccines that use the same antigen but different adjuvants.

Two subunit COVID-19 candidate vaccines, developed by the Vaccine and Infectious Disease Organization at the University of Saskatchewan are now undergoing human clinical trials.

Dr. Trina Racine, the Director of Vaccine Development with VIDO, says the two vaccine candidates use the same antigen but different adjuvants.

Clip-Dr. Trina Racine-Vaccine and Infectious Disease Organization:

A subunit-based vaccine is a vaccine where we take a protein from our virus of interest and we make just that protein in the lab and then we typically combine it with an adjuvant and an adjuvant is a compound that helps boost our immune system to recognize that protein so that we produce a better immune response when we get vaccinated.

Our two subunit-based vaccines are called COVAC-1 and COVAC-2 and the two candidates contain the same S1 antigen.

The S protein on the SARS-CoV-2 virus is the spike protein.

It's the one on the outside of the virus that it uses to attach to our cells to gain entry.

So, we've developed and we've manufactured that S protein in our facilities and then we've combined it with two different adjuvants and that's what the difference is between the two vaccines.

Our COVAC-1 vaccine is combined with an adjuvant called TriAdj that we actually developed here at VIDO and our COVAC-2 vaccine is combined with an adjuvant called Sepivac SWE and the SWE stands for an squalene-in-water emulsion.

An emulsion adjuvant is a well-known adjuvant in the field that is known to induce an immune response.

Dr. Racine notes COVAC-2 is currently in Phase 2 testing in Uganda and clinical testing as a “booster” vaccine at four Canadian sites while COVAC-1 is in Phase 1 clinical trials is at four Canadian sites and in clinical testing as a “booster” vaccine.