Consistent end-of-summer trend has doctors recommending precautions like vaccination, staying home sick. Image: CBC
COVID-19 activity is climbing across parts of Canada, with experts pointing to a familiar late-summer pattern. Doctors say this is the time to stay cautious, as the shift indoors and return to schools create conditions for the virus to spread more easily.
Wastewater surveillance, one of the most reliable indicators of community infection, shows moderate viral activity nationwide. Levels are particularly high in Vancouver, Calgary, Edmonton, Winnipeg, Montreal South, and Prince Edward Island.
“It’s moving in the same direction we’ve seen before,” said Dr. Lynora Saxinger, an infectious diseases physician at the University of Alberta. “We may see the typical late-summer rise, which often leads into a fall or winter surge. Of course, it’s still unpredictable.”
Numbers Point to a Clear Trend
The latest federal data highlights a positivity rate of 8.5 per cent among people visiting emergency departments for respiratory symptoms. Earlier this year, that figure had dipped to just under two per cent in March.
The late-August climb is not new. In fact, it has become a yearly occurrence. Test positivity was 16.9 per cent at the end of August 2024, and 13.4 per cent in the same week of 2023. While the exact numbers differ, the seasonal trend is consistent.
Variants and Vaccines
Like influenza, COVID-19 evolves and immunity weakens over time. The variants circulating today are all offshoots of Omicron, which has been dominant since late 2021.
The current Omicron subvariant, known as XFG, typically causes mild to moderate illness. According to microbiology professor Lawrence Goodridge of the University of Guelph, upcoming vaccines expected this fall should protect against it.
Goodridge, who leads wastewater surveillance projects, explained that scientists test blood samples from vaccinated and previously infected people to assess vaccine effectiveness. “The new shots should provide protection against XFG,” he said.
Lessons from Previous Years
Fall has always been a season when viruses thrive. Colder air and closer contact indoors create perfect conditions for transmission. Dr. Saxinger believes Canadians should apply lessons learned from past years.
“If you’re sick, stay home from school or work,” she advised. “That’s one of the simplest but most effective ways to prevent spread.”
She added that while most infections are manageable, the virus still poses risks for certain groups. People over 65, those with underlying medical conditions, or individuals who have not been recently vaccinated remain more vulnerable.
For them, antiviral treatments are available and can help reduce the chance of hospitalization.
What Canadians Should Know
Experts say the country is not heading for a pandemic-level surge. However, there is an expected increase in infections as the season changes.
“There are groups who should absolutely get the vaccine, and others for whom it’s optional,” said Dr. Isaac Bogoch, pointing to Canada’s national immunization guidelines.
The fall rollout of updated vaccines is expected to begin soon. Until then, doctors encourage precautions such as frequent handwashing, avoiding large gatherings when unwell, and consulting health professionals about vaccination.
“The key takeaway is simple,” Bogoch noted. “If you have questions about your risks or the vaccine, talk to your health-care provider.”
