EDMONTON -- An Edmonton-based lab is readying two COVID-19 vaccine candidates for clinical human trials this summer.

The potential vaccines displayed "really potent antibody response" when used in animal models, explained the University of Alberta’s Dr. John Lewis.

This means the potential vaccine neutralized the infection and prompted a T-cell response that recognized and eliminated SARS-CoV-2. The T-cell is a type of white blood cell involved in immune response.

“It turns out that your body, when it’s mounting an immune response against a virus, it can either produce antibodies – so antibodies that sort of bind it and prevent it from infecting cells – or we can produce T-cells – which kind of seek out infected cells in your body and kill them," Lewis told CTV News Edmonton in an interview on Friday.

The challenge, Lewis described, is that coronaviruses’ antibody response is a double-edged sword because they can sometimes increase infection. 

Dr. John Lewis

Normally, Lewis, as the university’s Frank and Carla Sojonky chair in prostate cancer research, spends his time researching genetic medicines.

Traditionally, vaccines have used an activated virus to produce an immune response in the body.

“A DNA or RNA vaccine," he explained in comparison, "just injects the instructions, and those cells in your body take up those instructions and make the virus proteins.”

His company, Entos, uses technology to directly fuse DNA with cells when developing DNA vaccines.

“When the pandemic hit, we saw an opportunity basically to take this technology which is ideal for developing vaccines for cancer and apply it to COVID-19," Lewis said.

According to the doctor, DNA vaccines offer more flexibility in that they can be created with different combinations for coronavirus proteins, and are easier to manufacture than messenger RNA (or mRNA) vaccines.

Lewis’ team of about 20 spent two months examining 24 different combinations of coronavirus proteins for the most durable and applicable potential vaccine.

The two frontrunners will head into the first phase of human testing in August, when researchers will be focused on the safety of using the vaccine in a young, healthy population.

If successful, they would then study a candidate vaccine’s efficacy while expanding phase one to include seniors, who produce less immune response and therefore need higher doses.  

The work is partially funded by a $4.2-million grant from the Canadian Institutes of Health Research.

Entos, COVID vaccine, lab

While Lewis is confident in having a few potential vaccines ready for trials this year or early 2021, he was less certain the world would have a COVID-19 vaccine in the 12 to 18 months that have previously been estimated.

Vaccines often take up to 10 years to develop, and some diseases – like SARS – slow before one can be created.

“The real challenge with COVID-19 is time," Lewis said, speaking of the virus’ mortality rate and economic impact.

“Clearly in this instance, every day counts.”

With files from CTV News Edmonton’s Laine Mitchell