TORONTO -- A new, more contagious variant of COVID-19 that first surfaced in the U.K. has been detected in Canada, something health experts had already predicted.

Ontario’s Associate Chief Medical Officer of Health, Dr. Barbara Yaffe, announced Saturday that there are two confirmed cases of the coronavirus variant in Durham region. The patients who tested positive are a couple, now in self-isolation.

“I’m not surprised,” Dr. Brian Conway, medical director of the Vancouver Infectious Diseases Centre, told CTV News Channel Saturday, in the wake of the news. “Obviously, this variant has been circulating for some time before it was actually recognized.”

In a news release announcing the cases, Dr. Yaffe said this “further reinforces the need for Ontarians to stay home as much as possible and continue to follow all public health advice, including the provincewide shutdown measures beginning today.

Durham Region Health Department has conducted case and contact investigation and Ontario is working in collaboration with our federal counterparts at the Public Health Agency of Canada."

The PHAC said in a statement Saturday that they believe there are more cases out there.

“As the monitoring continues, it is expected that other cases of this variant and other variants of concern may be found in Canada,” the statement reads. 

But even before today’s confirmation that this coronavirus variant is in Canada, health experts suspected it was already here. 

"It's spread to other countries," Ronald St. John, the former director-general of the Centre for Emergency Preparedness and Response at the Public Health Agency of Canada (PHAC), told CTV News Channel earlier on Saturday.

"Since it's been found since September, there's no reason why people coming since September haven't been able to bring that new strain to Canada." 

The new variant that emerged from the U.K. has since been found in other countries around the world, including France, Japan, Israel and Sweden.

Only two days ago, PHAC said in a statement that there had been "no evidence of these variants in Canada to-date" and that it was enhancing screening and scrutiny of quarantine plans for inbound passengers.

The Ontario news release on Saturday thanked the “proactive work” of the PHAC in locating the two cases of the new variant.

Conway said that more measures need to be taken to understand how the variant made its way into Canada.

“We need to do much more testing, we need to understand where this couple became infected,” he said, adding that we can only interrupt the “transmission chains” if we understand them.  

On Dec. 20, Prime Minister Justin Trudeau announced a restriction on flights from the U.K. to Canada in an effort to prevent the new variant from coming to Canada. That restriction has since been extended to Jan. 6.

According to the PHAC’s Saturday statement, travellers who arrive to Canada are also being asked “additional health screening questions to help identify if their travel itinerary included a country concern reporting this variant in the last 14 days.”

St. John said these measures may have come too little, too late.

The two cases announced today have no travel history, high-risk contacts or known exposure.

"It's a question of if the horse is out of the barn already, and are we closing the doors too late?" St. John said. 

Kirsten Fiest, an epidemiologist at the University of Calgary Cumming School of Medicine, also said stopping flights from the U.K. may not be enough to prevent the new variant from spreading in Canada.

"Almost certainly, it's spread even further than we know right now," Fiest told CTV Calgary. "If something can spread really quickly and rapidly and it increases the likelihood of infection, then our biggest concern should be long-term care facilities." 

PHAC said in their statement that the lack of a clear link to travel in the new cases in Durham Region underlines the importance of minimizing community transmission.

“As these two cases did not travel outside of Canada, it is important to follow public health measures and limit contacts with others, to reduce the transmission of the virus and any of its variants in communities,” the statement says.  

The new variant of the virus "may be up to 70 per cent more transmissible than the original version of the disease," U.K. Prime Minister Boris Johnson said in a press conference on Dec. 19, though a new study from the London School of Hygiene And Tropical Medicine suggests the virus is about 56 per cent more contagious.

“While early data suggests that these new variants may be more transmissible, to date there is no evidence that they cause more severe disease,” PHAC stated Saturday, adding that more research needs to be done. 

Two other variants of COVID-19 have also been found in Nigeria and South Africa, leading Canada to expand screening and monitoring measures on flights inbound from South Africa.

“We need to be on the lookout for other variants,” Conway said. 

St. John said both variants need further study to understand how variations in the genes could impact the behaviour of the virus and its effects on how the disease presents itself in the people who have contracted it, adding that the variant found in South Africa also appear, "at this point," to be more contagious than the base strain of coronavirus already in Canada.

As to whether or not the vaccines already being delivered in Canada will be effective in defending against these new variants, St. John said he doesn't believe the virus will mutate in the same way seasonal influenza does, and that the vaccines will likely be effective.

"So far, as near as I know, the vaccine targets many different parts of the virus," St. John said. "So it’s a good thing that it does, and that the virus probably will not escape the vaccine."

Conway added that there is “no evidence that the vaccine works less well,” on the variant that first emerged in the U.K. 

BioNTech CEO Ugur Sahin has also said he is "confident" his company's vaccine, created with Pfizer, will be effective against the new U.K. variant of the virus.