TORONTO -- Two people from Ottawa who returned from a trip to Nigeria have tested positive for the new COVID-19 variant of concern that was first detected in southern Africa, Ontario health officials reported Sunday.

They are Canada's first two cases of the B.1.1.529 variant, also known as omicron.

Ontario Health Minister Christine Elliott and Chief Medical Officer of Health Dr. Kieran Moore said in a joint statement that the patients are in isolation and Ottawa Public Health is conducting case and contact management.

"Ontario is prepared and ready to respond to this new variant," the statement read.

"The Ontario COVID-19 Genomic Network is continuing to actively monitor for all potential variants circulating in the province, including the Omicron variant, and is conducting genomic sequencing on 100 per cent of eligible COVID-19 positive samples."

According to the World Health Organization (WHO), officials in South Africa reported the variant on Nov. 24, with the first confirmed case coming from a specimen collected on Nov. 9.

The WHO said some of the omicron variant's mutations are concerning. It added that preliminary information appears to show that there is an increased risk of reinfection with omicron compared to other variants of concern.

Following the emergence of omicron, several countries, including Canada, announced travel restrictions for southern African countries. Nigeria is not on the list of countries affected by Canada's travel ban.

Federal Health Minister Jean-Yves Duclos said in a statement that he has spoken with his provincial counterpart about Canada's first two confirmed cases of omicron.

"This development demonstrates that our monitoring system is working," he said.

"As the monitoring and testing continues with provinces and territories, it is expected that other cases of this variant will be found in Canada."

Cases of the omicron variant continue to be detected in more countries around the world. On Sunday, Australia and The Netherlands also confirmed their first cases of the variant.

'A matter of time'

Infectious diseases specialist Dr. Isaac Bogoch told CP24 Sunday afternoon that he is not surprised that the variant is in Ontario.

"I think it's fair to say that this variant probably emerged weeks or even months ago. And by the time you start identifying it, it's usually pretty widespread, especially for a very contagious respiratory viral infection like this," Bogoch said.

"I think it was just a matter of time before we were going to see some cases in Canada. And like they said in that press release, it's not going to be surprised anyone if more cases are identified in the near future."

Bogoch said there are still a lot of unknowns about omicron, including how effective are the approved vaccines against it.

"We have a genetic fingerprint of this variant. We know what the genes are there. That's why this variant was listed as a variant of concern. That's because it has the genetic markers that have the potential -- keyword the potential -- to make this more transmissible or to start chipping away or eroding at some of the protection we would get from our vaccines, or from recovery from infection," he said.

"But we have to remember to it's not just the genetics of the virus. It's also other properties of the virus as well. So, there's the genetics. We have to see how this virus behaves in the clinical realm. And we also have to see how this virus behaves in an epidemiologic realm as well. Is it more transmissible or not?"

What Ontario needs to do, Bogoch said, is to ramp up testing, expanding vaccinations, especially making third doses more widely available to the eligible population.

He also added that public health measures in place need to remain.

When asked if the federal government should implement more travel restrictions, Bogoch said those policies are not effective.

"I appreciate that there's an urgent need to do something. There's an urgent need to appear that we're doing something meaningful. But you know, once you have a transmissible viral infection, that's well beyond those particular borders," he said.

As for what is needed to be done to prevent the emergence of new variants, Bogoch said more vaccines should be sent to countries struggling to access them.

"I think we need a tremendous global push to enable access to vaccines in parts of the world that don't have access to them or to the same extent that we do," he said.

"And on top of that, to ensure that programs are supported such that those needles go into the arms."

- with files from The Associated Press