Illustration by Megan Koch

U of C’s Dr. Craig Jenne explains why it’s still important to get your seasonal flu vaccine amidst the pandemic

By Rachneet Randhawa, December 1 2021—

It’s officially flu shot season. The current crisis of seasonal influenza and getting the flu shot in the context of the ongoing coronavirus pandemic include the controversy of the anti-vaccination movement. Both COVID-19 and the seasonal flu are contagious respiratory illnesses that have similar symptoms. The ideal time to receive the shot is from September to early October as flu cases are expected to accelerate early into October and continue until May.

According to a research study conducted by the CDC and an article by Purdue University’s Libby Richards, the effectiveness of flu vaccination from 2019-2020 was 50 per cent overall — and 55 per cent in youth — and estimated to prevent 4.4. million flu-related illnesses, 58,000 flu hospitalizations and 3,500 deaths. Regardless, why are vaccination rates low? The Gauntlet sat down for an interview with Dr. Craig Jenne, an associate professor in the Department of Microbiology, Immunology and Infectious Diseases and a member of the Snyder Institute for Chronic Diseases at the University of Calgary to learn more

“The flu vaccine is a shot we get every year,” said Jenne. “And what this shot contains is a couple of the proteins that are on the surface of the influenza virus. The purpose of this is to expose your body and to show your immune system what this year’s flu virus is going to look like, and then dealing so our body can start to build defences. Specifically, our body builds antibodies against the flu virus. So if later in the season we’re exposed to that virus, the antibodies can bind to it, neutralize it and stop it from entering and infecting ourselves.” 

It’s important to get the vaccine every year as the flu virus changes a lot — it’s like a professional shapeshifter. As a result, our immune system is essentially blind to this new version of the flu every fall. To avoid significant disease, clinicians match a vaccine to that new flu strain every year. 

“We don’t think of the flu shot as a booster. We think of this as a new vaccine every year that is designed specifically for the flu strain we anticipate facing here in the province,” said Jenne. “So even if you got the flu shot last year, the virus will be different this year and you need another vaccine to educate your immune system about the new version of the flu virus.” 

Do you ever wonder why the flu vaccine is less effective some years compared to others? Unfortunately, there is no one-size-fits-all solution and we can’t instantly make a vaccine, according to Jenne. It takes several months to have a vaccine ready when the flu arrives in Alberta, let alone North America. The flu spreads far and wide and becomes an amalgamation of places like Australia, China, New Zealand and other places in the southern hemisphere, as the seasons are opposite — our summer is considered their winter and the peak of flu season. 

“So the virus is circulating around the southern hemisphere and we anticipate that the virus will, as the seasons change, move its way north on travellers,” said Jenne. “So we take a look at that virus and basically make our best guess at what the virus is going to look like several months down the road — we make a vaccine for that.” 

In some years, the virus may change a little bit as it works its way up north and picks up an extra mutation or two. And in those years, the flu vaccine becomes a poor match. But despite it all, it’s important to remember that even in those years where the vaccine is not a good match, the vaccine will prevent those affected from ending up in the hospital. 

“So even a badly matched flu vaccine still has a dramatic protective effect of keeping people out of the hospital and really keeping serious disease away,” said Jenne. 

Before COVID-19 arrived, the seasonal flu was the leading cause of death from infectious disease in North America. Add to the fact our hospitals and health care system are under significant strain from the pandemic at full capacity, there is not simply any room for additional patients in the hospital and ability to offer beds to everybody who has the flu, Jenne mentioned. By getting the flu shot, you reduce the chances you’re going to develop the flu which has very similar symptoms. 

“So given the heightened security around COVID-19, it’s essential we do not develop symptoms for the flu and the best way to do that is to get vaccinated,” said Jenne. 

But what exactly is the difference between the two different virus families of Influenza and Coronavirus? These are both viruses but that’s the only thing they have in common. 

“They both happen to infect our airways. But this is like saying a whale and a giraffe are both mammals,” said Jenne. “So they’re very different entities and that really there’s no cross-protective immunity. If you’ve had the flu, there’s no protection against the Coronavirus. If you’ve been vaccinated or had the Coronavirus, it offers no protection against the flu.” 

Last year, nobody caught and died from the flu in Alberta due to the onset of COVID. After having done genetic tests and examining the genetic material of the flu, researchers were unable to identify any positive cases. There are a couple of reasons for this. For one, we had very little travel in the last flu season which meant that viruses couldn’t move around on their own. A virus needs travellers to pick them up in other parts of the world that have a flu season to bring them back to Calgary. With limited travel there was a lesser chance of importing the virus. Second, even with the few cases of flu that might have arrived, people were mostly going into quarantine as travellers, wearing masks, not gathering indoors and washing their hands — surprisingly all things that work against other transmissible diseases and not just COVID-19. However, now that border restrictions have eased up with no quarantine requirement for vaccinated travellers, we are back to the basics of taking higher precautions. 

“So we do anticipate the flu to be spreading much more like a normal season this year. And in fact, we already have confirmed cases here in Alberta right now,” said Jenne.

As for the rate at which  Albertans get vaccinated on average we are slightly below the cutoff of 40 per cent which Jenne said was quite disappointing. For influenza, the optimal level is something above 60 per cent for community-level protection. 

Nonetheless, the number one key reason Jenne believes vaccination rates are low, is due to the stereotype that young people are able to recover quickly.  

“It seems to be more of a belief that if somebody is young and healthy, there’s no need to get vaccinated. And for a large percentage of people, the personal risk of disease is fairly low when it comes to fluids,” he said. “It’s nasty, it’s inconvenient but your personal health risk is rather low. What we tend to forget, though, is even though your personal health risk is low, you do present a threat to others.” 

As long as the virus can spread through the community, we will still have hospitalizations and tragically still lose Albertans to the flu. 

“And the best way to stop that is to get to that level of herd immunity by people volunteering to be vaccinated. And that will break the transmission chain of this virus that, as I said, prior to COVID actually killed more people in North America than any other infectious disease,” said Jenne. 

Another common misconception is if you have been vaccinated in the past you aren’t required to get vaccinated again every year. This is incorrect as the flu shot is not a booster but rather an entirely new vaccination every year. 

“Unfortunately, flu changes and the virus we experience every fall is fundamentally different — it has completely changed its coating,” said Jenne. “And that means it’s able to hide from our immune system. So every year when we offer a new flu shot, it’s not a booster for your last flu shot. It’s actually a vaccine designed for the new strain of flu that is approaching or circulating in North America.”

Jenne also addressed the heaps of misinformation that has been circulating against vaccination for the flu in which many of the arguments are similar to getting vaccinated for coronavirus. Similar to the COVID-19 vaccine, some believe that you can get the flu from the flu vaccine.

“There is always the misconception or the fear that they can get the flu from the vaccine,” said Jenne. “And we know that not to be true because the vaccines offered here in Alberta do not contain any virus or live virus, so it’s impossible to get it.”. 

Another misconception is that a mercury component is present in vaccines. Jenne agrees that, yes, there is mercury in a multi-dose vaccination but it’s a matter of perspective. 

“We have to look at that within the perspective of the vaccine in that it contains mercury that is really not an available format for our body to use or absorb,” he said. “We’ve often seen the argument that there’s more mercury in a can of tuna than there is in your vaccine.” 

Most anti-vaxxers misinterpret the vaccines as being a significant threat, when in fact when you closely examine the details of what’s in the vaccine, it’s not problematic. 

“We’ve been using the same approach to flu vaccines now for decades and we have a very good idea. We know exactly what the adverse events are, what the rate is and that level is extremely small,” said Jenne. 

As for adverse events which are associated with the flu shot, they are usually reported by the government and are transparent. Examples of adverse events include soreness and redness at the injection site which is just a function of your immune system responding to the vaccine. Others include Guillain Barre Syndrome, which are instances of inflammation around your nerves that is a significant side effect but often temporary. 

To treat any adverse reactions, individuals are typically asked to sit out a waiting period after getting vaccinated for 10 minutes or so to gauge side effects. 

“If it does, they can be treated, they are reversible,” said Jenne. “But even then, these are extremely rare events, far less than the number of Albertans that, for example, are hospitalized every year for flu, so you do have to look at a risk-benefit ratio.” 

As for mistrust around vaccines and how to alleviate some of the confusion, Jenne states that concerns to each individual are legitimate and you must take into account all the facts and evidence. 

“At the end of the day, people ask me, ‘Do I get vaccinated?’ And the answer is yes,” he said. “I personally trust the vaccines. I personally believe in the benefits. And I personally believe the risk is extremely small. So, when it comes to my personal health and those around me, we get vaccinated every year.” 


For those interested in getting vaccinated, more information can be found on the Alberta Health Services (AHS) website. You can also contact your local walk-in medical clinic or pharmacy near you to book an appointment.


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