Images are unavailable offline.

Healthcare workers wait for airline passengers at a COVID-19 testing center at Trudeau Airport in Montreal, on Feb. 19, 2021.

Ryan Remiorz/The Canadian Press

Canadian infectious disease experts say vaccines will continue to provide some protection against the Omicron variant – that this new threat does not put the country back to square one of the pandemic.

So far, there are at least five confirmed cases of the variant in Canada – four in Ontario and one in Quebec – and officials are investigating two more.

Omicron is causing alarm among scientists because it has a large number of mutations, including many on the spike protein, which some fear could make it more transmissible or better able to evade vaccines. Researchers are racing to determine what risks it may pose and should know more in the coming days and weeks.

Story continues below advertisement

Lisa Barrett, an infectious disease physician and assistant professor at Dalhousie University in Halifax, said she’s watching the situation with caution, but not panic. Even if the variant is more transmissible, we have ways to control the spread, she said, and while it may affect the efficacy of current vaccines, it won’t render them useless.

“I don’t think it means we’ve got to shut the world back down and I don’t think it means that none of our vaccines will work at all,” Dr. Barrett said. “That’s just not how vaccines work.”

WHO warns of ‘perilous’ spread of Omicron around the world

Responding to news of the variant, the federal government last week banned entry to foreign nationals from seven southern African countries where Omicron has been detected. Canadian citizens, permanent residents and people with status under the Indian Act who are returning from those countries will have to undergo testing, screening and quarantine.

But many experts say the travel restrictions are discriminatory, as the variant has been identified in numerous other countries, including Britain and Belgium, and that officials should instead focus on rolling out booster shots and reducing capacity for indoor gatherings.

Story continues below advertisement

At least two of the four cases in Ontario were confirmed in travellers from Nigeria, which is not on Ottawa’s travel ban list. They were picked up through random testing at Montreal’s airport, where the passengers landed before continuing to Ottawa. The province is investigating two more suspected cases and awaiting whole genome sequencing to determine if they involve the variant. The province and the federal government are working to contact a total of 375 people who arrived in Ontario in the past two weeks from the seven African countries subject to the travel ban.

Ontario Chief Medical Officer of Health Kieran Moore said the province has asked Ottawa to start testing all arrivals, not just people travelling from southern Africa.

Quebec Health Minister Christian Dubé said his government has contacted 115 people who recently travelled to southern African and instructed them to undergo another PCR test and isolate themselves.

Quebec will not tighten its public-health rules and will continue to study whether the variant is resistant to vaccines or more contagious, Mr. Dubé said. But he praised the federal government for acting quickly to tighten travel restrictions.

Story continues below advertisement

“The federal government, and I want to thank them for this, have been very, very rigorous.”

Mr. Dubé also urged Quebeckers to continue observing public-health rules about the wearing of masks indoors and limiting private social gatherings, as well as being careful while travelling.

“What we’re asking Quebeckers who travel abroad is to remain extremely vigilant.”

Federal Health Minister Jean-Yves Duclos attended a virtual meeting with his Group of Seven counterparts Monday that focused on the emergence of the new variant. In a joint statement issued after the meeting, the ministers praised the “exemplary work” of South Africa both in detecting Omicron and alerting others to it. The ministers also said the global community is faced, at its first evaluation, with a new and “highly transmissible variant of COVID-19 which requires urgent action.”

Story continues below advertisement

“There was strong support to set up an international pathogen surveillance network within the framework of the World Health Organization,” the statement said.

It also noted the need to ensure access to vaccines, tackle vaccine misinformation and provide operational assistance and support for research and development. The ministers committed to work closely with the WHO and international partners to share information and monitor the new variant. They plan to meet again in December.

Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the day’s most important headlines. Sign up today.