New COVID-19 subtype takes hold in Saskatchewan

Researchers have discovered that an offshoot of the delta variant has become predominant in Saskatchewan and Alberta.

At a Saskatchewan physician town hall meeting last week, researchers talked about the AY.25.1 subtype of the delta variant, which has become the most dominant form of the virus in the province.

So how concerned should people be about this new development?

"It certainly doesn't appear to be more virulent than the delta variant, meaning it doesn't cause more severe disease,' said Angela Rasmussen, a virologist at Saskatoon's Vaccine and Infectious Disease Organization.

"Of course, the delta variant itself is bad enough. So it's definitely something to watch, and it's clearly something that has really taken over the province."

Rasmussen told CBC Radio's Saskatoon Morning that it's believed the AY.25 subtype started in Idaho and eventually migrated into the Canadian Prairies.

She said as a coronavirus spreads through a population, it will continue to mutate. Eventually, a new sublineage may be created.

Rasmussen said the sublineage's dominance is a direct result of unchecked transmission, especially through people who are unvaccinated.

"We did have a huge surge, as did Alberta," she said.

"So, it's not tremendously surprising that we would see the emergence of a new variant sublineage."

Researchers believe the AY.25 subtype could be slightly more transmissible than the original delta variant. Jason Kindrachuk, a Canada Research Chair in emerging viruses at the University of Manitoba, said that slight increase doesn't come close to the jump in transmissibility that came with the delta variant.

"It would take something phenomenal to likely out-compete delta, and we're not seeing that," he said. 

"It's a sublineage of delta, it's not a brand new variant of concern."

Rasmussen said anyone who is concerned about the new subtype should make sure they are fully vaccinated against COVID-19.

"The good news here is that the vaccines are broadly protective against all the variants of concern that we've seen so far, including delta and including against this sublineage," she said.

"If we don't want to worry about this or any other sublineages in the future, the best thing you can do is go out and get vaccinated, because the vaccines do provide excellent protection."