Flu season is warming up now that the weather is cooling down, and medical experts are urging Canadians to get the flu shot to protect themselves and their loved ones.
With multiple strains of influenza circulating and hospitalizations beginning to rise in parts of the country, older Canadians and young children are especially at risk.
Medical experts are urging Canadians to get vaccinated against the flu, as the shot offers the best protection available — even if the strains in the flu shot aren’t a perfect match for those circulating.
“Some people mistake influenza for a little cough or a cold or a sniffle, and it is not. It’s a very serious virus that kills about 350,000 to 500,000 people per year on the planet, and it’s going to kill Canadians as well,” says Dr. Isaac Bogoch, an infectious diseases specialist at Toronto General Hospital.
“We can take steps to reduce our risk for influenza by getting the influenza vaccine.“
According to Health Canada, most of those who get the flu will start developing symptoms within one to four days.
Symptoms may include fever, cough, muscle aches and pain, chills, tiredness, headache, sore throat, loss of appetite and a runny or stuffy nose. Some people, mainly children, could also have diarrhea, nausea and vomiting.
Health Canada says these symptoms can also lead to more severe complications that can worsen chronic health conditions and lead to heart complications, pneumonia and respiratory failure, hospitalization and even death.
Bogoch says that although the influenza virus is always evolving, what remains a constant is that infections and hospitalizations rise around the same time each year.
“Predictably, we’re going to see a rise of these viruses through the fall and the winter, and that’s exactly what’s happening right now. Nothing is really all that new from both an epidemiologic and a clinical standpoint, and from how we can protect ourselves at the individual and the community level,” Bogoch says.
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“But I think it’s a good reminder to talk about it and to remind ourselves what tools we have available.”
Statistics from Health Canada show that as of Nov. 7, nearly two per cent of all Canadian tests were positive for influenza, which experts say is considered relatively low.
The rate is increasing, however.
“Nationally, indicators of influenza activity remain at interseasonal levels but have increased in recent weeks,” Health Canada says on its website, adding that the number of reported outbreaks and weekly hospitalizations were also considered low.
Medical experts say these numbers can change quickly, and the warning sign may be a rise in children becoming infected first.
“Overall, the percentage positivity is still low at around two per cent across the country, but what we’re seeing is that in school-age children in Ontario and Quebec, we’re above five, seven, and some groups even 10 per cent positivity,” says Dr. Jesse Papenburg, a pediatric infectious disease specialist at the Montreal Children’s Hospital of the McGill University Health Centre.
“So we’re seeing transmission of influenza in school-age children and that’s often the first group to get hit, and that’s when community transmission starts to really increase.”
A survey study from earlier this year found 72 per cent of Canadians think vaccinations for children should “probably” or “definitely” be mandatory, which has declined since the pandemic.
The same survey found 88 per cent were in favour of a similar mandate in 2018.
Health Canada’s data shows the number of reported cases of influenza in Canada is mostly among those aged 65 or older, also the main age category to go to the hospital as a result of the flu.
Children aged four and under are the second most common age group among those with influenza-associated hospitalizations, according to the government’s latest report.
Right now, there are three strains of the influenza virus circulating, according to Health Canada: two forms of Influenza A, known as H1N1 and H3N2, and Influenza B.
The flu vaccine currently available to all Canadians is tailored to protect individuals against all three strains, with Health Canada citing research showing the vaccine’s ability to match one of the strains may be somewhat “reduced” compared to the other two.
“At the end of the tail end of the southern hemisphere’s influenza season, there started to emerge a H3N2 strain that has a couple of mutations that would suggest that the vaccine might not work as well against this particular strain,” Papenburg says.
“We don’t know really in the field how good the vaccine is going to work against that strain, but it’s probably going to have some degree of effectiveness. We also don’t know yet if this is going to be an H1N1 predominant season or an H3N2 predominant season. It’s still too early to tell, so there’s a lot of uncertainty.”
Although medical experts say the vaccines aren’t perfect, they are still better to have than nothing at all.
“There’s three circulating viruses. You have reasonable protection against two and some protection against the third. I would take some protection over no protection any day — especially with influenza,” Bogoch says.
“This year, one of those three components might be a bit of a mismatch. That doesn’t mean it won’t work, it just means that there might be reduced effectiveness of one of these three components.“
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