TORONTO -- Keep your holiday gatherings small is the messaging from Canada’s top doctor, as new federal modelling points to a resurgence in COVID-19 infections in the coming weeks that could be further accelerated should the new Omicron variant take over.

The Delta variant remains the dominant strain in Canada and around the world, said Chief Public Health Officer Dr. Theresa Tam, but the spread of Omicron is increasing globally. In Canada, there are early signs of community spread.

While most of the 87 confirmed Omicron cases in Canada have been traced back to international travel and close contacts, cases with no known links to travel are starting to be reported, Tam noted during a press conference on Friday.

“Keeping private gatherings small is quite important at this point while we learn more,” said Tam.

“Gathering with a smaller number of people in well ventilated places – all of those layers of protection … can still enable us to have a good time while being safer and being precautionary.”

Travelling within Canada would be the “better choice” versus international travel, she added.

The current rise in new cases is primarily driven by Ontario and Quebec, with both provinces experiencing numbers not seen since spring. Should transmission rates increase by 15 per cent, or if Omicron takes hold under current levels of transmission, then Canada could see cases skyrocket to record levels above 10,000 cases before January, modelling charts show.

“We must approach the coming weeks with an abundance of caution and at the same time, we must be prepared to act quickly to control the spread at the first sign of rapidly accelerating cases,” said Deputy Chief Public Health Officer Dr. Howard Njoo.

So far, all documented cases involving Omicron in Canada have been asymptomatic or mild, and there is considerable uncertainty around the variant’s ability to evade immunity and cause severe illness, health officials said, but a rapid increase in cases could still strain the health-care system.

“That model doesn’t model the severity. But even if the proportion of those who get Omicron who gets severely ill is tiny – if you get enough cases, you still have enough severe outcomes to impact your hospitals and your ICUs,” Tam said.

Canada’s Rt, or effective reproduction number, has been back above one for the last five weeks, indicating that the epidemic is in a growth pattern, federal data shows, with the Delta variant accounting for more than 90 per cent of the cases.

OMICRON UNCERTAINTY

Despite the many unknowns around the Omicron variant, including whether it poses a higher or lower risk of severe illness and death, preliminary data indicates that it has the potential to spread faster than the highly transmissible Delta variant.

In South Africa, cases have climbed at a much faster rate with Omicron compared to previous waves.

While vaccines are expected to still provide protection against the new variant, scientists are still investigating the level of effectiveness.

“The Omicron variant of concern is a cruel reminder that a global epidemiological situation can change quickly. We all need to be prepared for that,” said Minister of Health Jean-Yves Duclos in a press conference on Friday.

Government of Canada COVID-19 forecast for Dec. 10
Source: Public Health Agency of Canada

VACCINE EFFECTIVENESS

With 80 per cent of the eligible population in Canada fully vaccinated, infection rates remain highest among children under the age of 12, a group that only recently became eligible for shots.

The size of outbreaks in schools and childcare settings remain small, however, at fewer than five cases, Tam said. In total, there have been over 380,000 reported cases in children up to 19 years of age, with less than one per cent involving severe illness.

Tam and Njoo continued to encourage vaccinating children aged five and up and providing boosters for those aged 18 and over, emphasizing that vaccines along with protective health measures will help control transmission and would significantly reduce risks of resurgence in 2022.

The risk of being hospitalized remains significantly lower for those who are fully vaccinated individuals, officials reiterated, noting that those who are unvaccinated between the ages of 12 and 59 are 32 times more likely to be hospitalized with COVID-19 than those who are fully vaccinated. For those above 60, they are 16 times more likely to be hospitalized.

Despite the warning about the coming weeks, Tam said that vaccines have provided substantial protection from infection and severe outcomes and dampened the impact of the delta-driven wave this past fall.

“This time last year, we were experiencing double the number of daily cases and more than double the number of people with COVID-19 being treated in hospitals and in intensive care daily. Most importantly, daily reported deaths are 82 per cent lower than this time last year,” Tam said.