TORONTO -- The annual flu shot will be more important than ever during the coronavirus pandemic, according to one infectious disease expert, who says it would be a “double whammy” to be infected with both viruses.

Dr. Abdu Sharkawy hopes the influenza vaccine, which is typically first available in October and November, is offered earlier this year.

“Even if it isn’t, I would hope that as many people as possible recognize that the flu shot is fairly effective, it helps protect yourself and everyone around you. So please get the flu shot,” he said Thursday on CTV’s Your Morning. 

“This is the one year you don’t want to miss it.”

As health officials prepare for a possible “second wave” or resurgence of COVID-19 infection in Canada in the fall, some have expressed concern that the flu season might overwhelm hospitals and compound efforts to stamp out the novel coronavirus if flu shot uptake is low. In the 2018-2019 season, just four in 10 Canadians reported receiving the influenza vaccine, according to the Public Health Agency of Canada. A recent national survey of 1,922 Canadians by Pollara Strategic Insights found that the uptake number could go up, with 57 per cent responding that they would “definitely or probably” get the shot in 2020. A similar global survey published last week in The Journal of Pediatrics identified a nearly 16 per cent increase in number of caregivers that said they plan to vaccinate their child against influenza in the coming season. Researchers suggested that "[c]hanges in risk perception due to COVID-19​" may be playing a role.

Lessons from the peak of the COVID-19 pandemic in March and April may also play a role in preparing Canadians for the flu season, both in hospitals and in the community, said Sharkawy.

“Knowing that we were vigilant in anticipating [a surge of infections] before, we’re well-equipped to handle [both] if the situation does arrive,” he said, noting resource deployment, infection control planning and improved testing protocols. 

Plus, Canadians themselves are more vigilant about public health measures such as hand-washing, physical distancing and masking than before the pandemic, he said. Australia, which is nearing the end of its winter, may serve as an example: the country experienced a major drop in influenza infections and deaths compared to the previous season. Experts credit COVID-19 restrictions and lockdown measures.

But the upcoming flu season could still prove challenging for hospitals since it can be difficult to differentiate between influenza and COVID-19 infection. In late February and early March this year, there were “undoubtedly” coronavirus infections mistaken for influenza, said Sharkawy. To avoid the same miscalculation, he expects coronavirus testing to ramp up this fall.

“I think it’s going to be very important to have rapid testing available to us so that we can easily distinguish between the two of them both inside and outside medical settings,” he said.

The ability to distinguish between the two won’t always be helpful though, since it’s “absolutely” possible to have concurrent infections of influenza and COVID-19, which are different viruses of different families. In a July case study, doctors in Japan warned of “coinfection” and described a 57-year-old restaurant worker who tested positive for influenza A, but as his condition failed to improve, he later received a positive COVID-19 test. How frequently this occurs is not known, but a pair of U.S. studies found that 2.1 per cent of patients in New York City and 20.7 per cent of patients in Northern California had a second respiratory infection in addition to COVID-19.

“Certainly that would be a double whammy we want to prevent,” said Sharkawy.

“It speaks to the importance of doing things like hand-washing, distancing and masking in indoor settings. All of these things work and they should help prevent both of these illnesses.”