TORONTO -- Cooler weather and easing restrictions are contributing to a rise in COVID-19 infections in some parts of Canada, Canada’s top health official said on Friday during a Public Health Agency of Canada (PHAC) update.

Chief public health officer Dr. Theresa Tam said there was an 11 per cent rise in new daily cases this past week, but said bumps in Canada’s downward trajectory were expected as provinces continued to lift gathering limits and as the colder temperatures drive people to spend more time inside.

“It looks like we may be experiencing a bit of turbulence this week,†Tam said.

“Most notably, coverage is not the same everywhere, and where there are pockets of very low coverage, there is a higher risk of local surges in virus activity in the weeks ahead.â€

Ontario and New Brunswick are among the latest provinces to see their curves bend upwards. In the last couple of weeks, Yukon has seen a near-vertical spike in cases, while Quebec and Nova Scotia have also experienced an ascending trend. The number of picked up in recent weeks as well, following a slow but steady climb since late summer. The province introduced new public health restrictions Friday to reduce the number of new cases.

Overall, the number of people with severe illness across Canada remains stable.

Tam said the demographic with the highest number of new infections continue to be children under the age of 12, who are not yet eligible for immunization. They represent more than 20 per cent of new daily cases, PHAC said last week, despite only accounting for 12 per cent of the country’s population. While most cases remain mild, severe illness have struck some children in rare instances.

A decision on whether to authorize the Pfizer-BioNTech vaccine for children aged five to 11 is expected within “the next one to two weeksâ€, said Canada’s chief medical adviser, Dr. Supriya Sharma during the conference. Last week, the United States authorized the use of the Pfizer vaccine for that age group.

BREATHING IN SUSPENDED “FINE AEROSOLSâ€

Tam also reminded the public that the virus can linger and remain suspended in the air as a fine aerosol, and stressed the importance of wearing a well-fitted mask with enough layers to filter out the fine virus particles when spending time in indoor public spaces, especially if the ventilation is poor.

“With a highly-contagious Delta variant continuing to predominate, the risk for surges in disease activity is likely to increase with more time spent indoors, particularly where there are pockets of low vaccine coverage,†she said, likening it to the way expelled cigarette smoke lingers in an enclosed space and inhaling secondhand smoke when in close proximity to someone infected.

Signs of waning vaccine protection may also be contributing to an increase in risk for more severe illness, making continued proper masking an important measure, she added.

More than 85 per cent of eligible Canadians are now fully vaccinated; just under 75 per cent if children under 12 are included. But with some having received the vaccine more than half a year ago, provinces and territories across Canada are now rolling out booster shots for eligible, vulnerable groups including long-term care residents, the immunocompromised, and front-line health-care staff. Earlier on Friday, Health Canada said it approved the booster shot for Moderna’s COVID-19 vaccine, Spikevax.  

Tam said that sizable gaps in vaccinations remained, however, with more than five million Canadians who are eligible still unvaccinated and more than 4.3 million children waiting for the vaccines to be approved.

With borders reopening, Tam also said that the pre-arrival PCR or molecular test requirement for travellers entering Canada was still being actively reviewed, and that there would be further information to come.