According to the data issued by Canada’s health agency for the week ending December 13, 2025, flu activity was “high and increasing,” with 27.7 percent of tests being positive. The agency’s Canadian respiratory virus surveillance report reveals that the percentage of tests positive for influenza continues to increase quickly and is similar to the highest value recorded in the past three seasons (27.6% the week ending February 15, 2025).
Laboratory detections are predominantly influenza A, and among subtyped influenza A detections, influenza A(H3N2) is predominant, according to the report. This flu season seems more significant than previous ones, Dr. Isaac Bogoch, an infectious disease specialist at the Toronto General Hospital, said.
Bogoch said that this is due to three viruses that are currently prevailing: two are influenza A, H3N2 and H1N1, and one is influenza B. In an interview to CTVNews.ca, he noted that the H3N2 flu strain is the predominant one.
“Years that are H3N2 dominant tend to put more pressure on (the) health-care system,” Bogoch told CTVNews.ca in an interview on Friday (December 19, 2025). “They tend to be more significant and tougher compared to an average flu year.”
Covid was stable in recent week
The latest Health Canada data also suggested that the percentage of positive tests for COVID-19 was stable in the recent reporting week. The percentage of positive tests for RSV, however, is slowly increasing. It is still below expected levels.
Flu-related outbreaks are rising
There is an increase in the number of flu-related outbreaks, with 284 reported. Of those outbreaks, 65 percent were associated with influenza.
The rate of respiratory viral hospitalizations reported by participating provinces and territories is also increasing. The number of hospitalizations for the week ending December 13 is more than 2,700, compared to nearly 2,000 reported the week ending December 6. The overall weekly rate of hospitalizations is 8.2 per 100,000 population.
Not too late to get the flu vaccine, says Bogoch
Bogoch has said that the take-home message is that it is not too late to get the flu vaccine. “The risk factors for severe illness are the older and younger cohorts, pregnant women, and people with underlying health conditions … but even if you don’t have risk factors, influenza can still cause a really nasty illness. People can get very sick from it,” he said, as quoted by CTV.
“The vaccine is not perfect, we know it’s not perfect, but it can still reduce the risk of getting the infection, and even if you do get the infection, it can still mitigate the severity of symptoms.”