McMaster doctors warn upcoming flu season to be more 'intense and pronounced' than previous years

Doctors from McMaster University expect a resurgence of flu in Canada this season, and are stressing the importance of preventive measures.  

With pharmacies experiencing flu and cold medicine shortages in recent months, several Hamilton-based immunologists urge Canadians to consider staying at home, masking, and flu vaccines to protect against sickness over the next few months.

"I certainly think that we should expect that we will see a more intense flu season than we've seen over the past couple of years, largely due to the easing of public health measures," said Dr. Matthew Miller of the McMaster Immunology Research Centre.

Miller, an immunologist, and Dr. Dawn Bowdish, also from the research centre, use flu data, provided by pharmaceutical company Aspen Pharmacare, from Australia, New Zealand and African countries to gauge what sort of flu season Canada will see in winter.

Both doctors told CBC they do not receive any financial compensation from Aspen Pharmacare.

Countries in the Southern Hemisphere are resolving their flu seasons right now, giving insight to trends that may be avoided in the north. Doctors make predictions on data from countries that have passed their flu season which can show patterns of lab-confirmed flu cases and flu-shot efficacy.

Data from Aspen Australia, for instance, shows that children five years old and younger, and between 10 and 19, were more susceptible to the current strain of flu. 

"Children tend to be the ones who are the most likely to get infected, have severe outcomes, and then bring the flu home to family members," said Bowdish.

Bowdish said it's important to practise stay-at-home measures if you're sick, whether you believe you have COVID-19 or not. She advises to try not to go to work when sick.

With children, she said, definitely keep them home. She also advises not to give children a fever suppressant in order to send them back to school. 

"Even though they might be feeling OK, they can still be spreading that illness," said Bowdish.

Children's medicine shortage

In a statement Oct. 7, Health Canada said it is working with medicine manufacturers to catch up to the demand for children's acetaminophen (like Tylenol) and ibuprofen (like Advil).

It said while it has approached several manufacturers, supplies in shops across Canada may continue to face "intermittent shortages" for the time being and to speak to health-care personnel in an emergency situation.

In the meantime, both Hamilton doctors suggest sickness-preventive measures like masking or taking a flu vaccine.

"Knowing that we'll almost certainly have a resurgence of flu this year I think underscores the need to make sure we take the appropriate [preventive] measures to avoid overwhelming the health-care system again," said Miller.

The presence of both the flu virus and COVID-19 hitting at once this upcoming winter has the potential to overwhelm Canada's already over-stressed hospitals. 

On Monday, Prime Minister Justin Trudeau also encouraged Canadians to update their COVID-19 and flu vaccinations.

"If we are able to get a high enough of level of vaccination, we reduce the danger of having to take other health measures to make sure that we're all safe and not overloading our hospitals," Trudeau said.

Ontario's Chief Medical Officer of Health Dr. Kieran Moore said last week that he'll recommend the return of mask mandates if the province's health care system becomes too strained.

The data from Aspen Australia showed flu vaccines are about 40 to 60 per cent effective at preventing influenza spread or severe symptoms after getting the flu. 

"But one of the things that's very, very important with influenza is getting some vaccines back in the arms of children," said Bowdish.

"It's been shown again and again that flu vaccines, vaccinating children, prevents or reduces the amount of influenza in entire communities."