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The seasonal flu shot, is it right for you?

The weather is getting colder and the holidays are only a few weeks away. Unfortunately that also means that flu season is approaching. Currently (and in recent years) there is a lot of media buzz over getting your flu shot but is it really necessary? You should make an informed decision about your health and I hope to clarify some points about the flu shot. At the end of the day, it is a personal decision that you should discuss with your physician.

What’s the difference between the cold and flu? How bad is the flu?

Both the cold and flu are caused by viruses which mean that antibiotics aren’t effective for treating these illnesses. They share some common symptoms such as runny, stuffy nose and sore throat. The flu can be more severe and lead to hospitalization or serious health problems like pneumonia. Flu specific symptoms include high fevers, muscle aches and fatigue lasting anywhere from 2-10 days. Symptoms vary from person to person, for example children may present with earaches.

The Ministry of Health in Ontario infographic suggests 300 preventable deaths occur in Ontario every year from the flu. The Public Health Agency of Canada suggest 2000 – 8000 Canadians die of the flu and its complications every year. This article by CBC from 2012 ( suggests that the number of deaths estimated by public health agencies are inflated to scare people into getting the flu shot. This is due to the fact that the flu tends to affect people who already have an underlying disease and poor documentation on deaths caused by flu. Without this data, models are used to predict the number of deaths caused by the flu and that’s where we get such a large discrepancy in numbers. The break out of H1N1 flu in 2009 resulted in 428 deaths in Canada, which is closer to the seasonal average of 300 deaths recorded in the vital statistics table than the estimates from flu models.

How does the flu shot work?

Check out this video for an explanation of how the vaccine is made and how it works:

Scientists predict which flu strains will be the most prevalent this season based on research and develop a vaccine based on those strains for the year. This means that the flu shot can change every year based on which strains are circulating. If you got the flu shot last year, that doesn’t mean you will still be protected this year. The flu shot is 60-80% effective in preventing the flu if the strains are well predicted this season. The vaccine contains dead flu virus that is used by the body’s immune system to develop antibodies against the virus. It takes approximately two weeks to develop protection to the predicted flu virus strains. If you encounter the flu virus after this period, your body will already have the antibodies to fight the virus and your immune system is better prepared to fight off the infection.

Since the virus is already dead, you can’t catch the flu from the vaccine. You may however get some redness and pain from the injection site or a low-grade fever as your body’s immune system responds to the inactivated flu virus. There is also a chance of getting Guillain-Barre syndrome from the flu shot, however you are more likely to get it from the flu than the flu shot. Guillain-Barre is an autoimmune disease that attacks the nervous system.

What else is in the flu shot?

The vaccine contains thimerosal (ethyl mercury) which is used as a preservative. The amount of mercury found in the vaccine is about the same as the amount in a can of tuna. The vaccine also contains egg proteins and may not be appropriate for people with egg allergies depending on the severity of their allergies. Formaldehyde and aluminum are also found in the flu shot. All the ingredients in the flu shot are shown to be safe and are highly regulated by Health Canada.

Who can and can’t get the flu shot?

The flu shot is encouraged for everyone older than 6 months old. People with compromised immune systems are especially urged to get the flu shot including children, seniors, and those with underlying medical conditions that are at higher risk for getting the flu. The flu shot is also safe for pregnant and breastfeeding women. Getting the flu can cause more issues for pregnant women than the shot itself.

If you have severe egg allergies or allergies to any of the other ingredients in the flu shot, please talk to your physician if the flu shot is appropriate for you or if there are alternatives. People who have a history of Guillian-Barre syndrome should also discuss with their physicians to see if the flu shot is appropriate for them.


B-Fit and stay flu free this season!