Skip to main content

That yearly tempest we know as the flu has begun brewing. Although it may not garner the same excitement and concern as other headline-grabbing viruses (such as Ebola and enterovirus D68), this pathogen deserves our attention.

Flu season typically starts around now and lasts until about April. In that time, up to a quarter of the Canadian population will become infected. A normal flu infection for the average person isn't necessarily a full-blown health crisis, although it is a burden. It starts off with a fever, sneezing, painful coughs and sore throat. As the virus gains a hold inside the respiratory tract, the body reacts with an inflammatory response. This results in muscle aches, flared joints and problems with the gastrointestinal system leading to nausea, vomiting and diarrhea. The battle can take upwards of three weeks to win and leave any victim drained from the ordeal.

But should a person have a weakened immune system, due to age, medication or chronic disease, the outcomes may be far worse. Up to 20,000 Canadians end up in the hospital every year as a result of complications, which can include bacterial pneumonia, heart disease and even organ failure.

The subsequent fatality rate is normally less than 1 per cent; the Public Health Agency of Canada estimates some 2,000 to 8,000 people will lose their lives (though some question this number, as flu deaths aren't tracked across Canada).

But even though there is a vaccine to help protect against the flu, there is a problem: On average, less than half of all Canadians get the flu shot each year.

Scientific evidence does not support most of the reasons people cite for skipping the shot – everything from fear of adverse reaction to the belief that it is ineffective. Each year, vaccines are tested for their safety so that events such as chest tightness, difficulty swallowing, facial swelling and red eyes are minimized. The vaccine contains stabilizers, preservatives and immune-boosting agents called adjuvants but none of these are proven to be toxic. Also, some vaccines may contain live virus but they have been genetically altered so they cannot cause infection; they are safe.

Research has continued to develop even safer versions of the vaccine. When first offered, there were only a few options. Today, there are 10 different types available in Canada. Each one is specially formulated for specific health needs including age, pregnancy status, allergy to eggs, compromised immune system and the presence of chronic conditions such as lung and heart disease. The choice is determined by a health professional who either knows an individual's medical history or through a fillable form provided prior to getting the shot.

As to the claim the vaccine is ineffective, we know the shot is about 60-per-cent effective, on average, in healthy adults.

Furthermore, confusion persists around the way the flu vaccine works. The concept of vaccination has been around since 1796, when Edward Jenner discovered the first vaccine against the now eradicated smallpox virus. Although times have changed significantly since then, the premise of vaccination remains the same. By introducing the body to a non-infectious dose of a particular pathogen, the immune system can be trained to fight off a real attack.

The process relies on the dual nature of the immune system, which has an acute short-term action as well as long-term memory. A vaccine stimulates both elements such that the immune system acts at a low level against the vaccine. Then, with time, the body develops a recall mechanism so a rapid and effective response will be engaged later on.

The influenza vaccine, which has been around for over 60 years, is made up of a combination of different strains in low enough doses to prevent infection yet stimulate the two prongs of the immune response.

The vaccine has been available for free in Canada since 2004, which is beneficial as a new variation is required every year to tackle the quickly evolving virus. New strains capable of evading the previous year's immune memory can develop between flu seasons.

When it comes to getting the flu shot, there is no doubt it is a personal choice. Yet the short- and long-term benefits are proven: You have a good chance of preventing the three-week deluge of symptoms and, for those most at risk, of complications, hospitalization and even death.

Even with the variety of vaccine options, not every Canadian will qualify for the flu shot due to a number of health-related reasons, such as age, depleted immune function including autoimmune disorders and certain medical treatments. To protect them, you need to protect yourself. By taking the vaccine, you are doing a double service by ensuring your own health, as well as helping to keep others healthy. That alone is surely worth a jab in the arm.

Health Advisor contributors share their knowledge in fields ranging from fitness to psychology, pediatrics to aging.

Jason Tetro is a Toronto-based microbiologist with over 25 years experience in research. He is a self-described germs relationship therapist and strives to improve humanity's bond with the unseen world. He writes for national and international media outlets and is often found on social media where he shares his unique views on microbial health. His book The Germ Code is a science bestseller. You can follow him on Twitter at @JATetro