While the fourth wave of the COVID-19 pandemic is slowly ebbing away, Canada's top doctor said that doesn't mean the pandemic is likely to end this winter — even with widespread vaccinations.

The country is bending the curve, but progress has recently slowed and Canada could still see some "bumps" over the next few months.

"Now is not the time to let our guard down. We could still be in for a challenging winter," chief public health officer Dr. Theresa Tam said at a briefing Friday.

Tam welcomed the high level of vaccine coverage across Canada, and said some regions are seeing very low COVID-19 activity.

In the last week there were an average of 2,230 new cases being reported daily across Canada. That's half as many as were reported during the peak of the fourth wave when there were more than 4,400 daily cases.

But she warned regional differences in vaccine coverage could still create surges in months to come, even if the upswings could be less dramatic and widespread.

The winter makes for prime conditions for COVID-19, as people retreat indoors from the cold.

"I think we should look probably towards the spring, when we will be in a better position," Tam said.

She pointed specifically to provinces like Saskatchewan and Alberta where vaccination rates are low and new cases are still higher than the rest of the country, which has prolonged the heavy strain on their health systems.

#Pandemic likely to continue through the winter, says Canada's top doctor. #COVID19 #CDNPoli

"Other regions that relaxed too many measures too quickly, before adequate vaccination coverage was achieved, experienced a sharp and large rebound in disease activity, followed by a similarly sharp increase in severe illnesses that remain elevated," she said.

Other regions, including Yukon, Northwest Territories and northern Manitoba, have relatively high vaccination coverage, but are still coping with a high number of cases.

Tam said that could be because people in those regions were vaccinated earlier, and are now experiencing waning immunity. It may also have to do with living conditions in those parts of the country, such as crowded homes.

"Some of those social, economic environments and health inequities can put people at a higher risk of getting exposed to the virus as well, so even a high vaccine coverage may not be quite enough," Tam said.

Tam said the virus has proven time and again that it is adaptable, and Canada must remain vigilant against new variants and new waves of infection.

"I don't think we're out of the woods. I think we should look probably towards the spring, when we will be in a better position," she said.

Still, Canada has been trending along the most optimistic projections the public health agency released last month. The longer-range forecast suggests that cases could continue to decline if current transmission rates are maintained.

For the first time, reported cases nationally are now most commonly children under the age of 12 who do not qualify to be vaccinated against COVID-19.

Children under 12 make up about 20 per cent of new daily cases, Tam said, though they represent only 12 per cent of the population.

However, Tam said outbreaks in school and daycares have been smaller this wave, suggesting they are being closely monitored.

Less than one per cent of children who have been infected by COVID-19 have developed serious illness, Tam said.

Pfizer-BioNTech has applied for approval of a pediatric vaccine for children age five to 11, but Tam said the results of Health Canada's review may be some weeks away.

If deemed safe and effective, that vaccine could protecting that young population and driving down national case counts, Tam said.

This report by The Canadian Press was first published Nov. 5, 2021.