Flu Shot FAQs

Do I need to get the flu shot?1,2

It is highly recommended to get your flu vaccine to reduce your chance of getting the flu and decrease the severity of infection if you do get it. Except in rare circumstances, everyone six months of age and older are strongly encouraged to get their flu shot, especially certain groups of people such as individuals who are at high risk for complications and those who may come into contact with them. Speak to your pharmacist for more information.

How effective is the flu vaccine?2,3

The effectiveness of the flu vaccine can vary each season and is affected by factors such as the health and age of the recipient and how well the vaccine strains match the influenza viruses in circulation. The 2018/19 flu vaccine was estimated to be approximately 72% effective. Although the vaccine may not be an exact match each year, it is still important to receive the flu vaccine since some protection is still better than none.

When is the best time for me to get the flu shot?2,4

You can get your flu vaccine anytime during the flu season between October and March, but it is recommended to get it as early as possible so that you are protected. Keep in mind that it may take up to two weeks after getting the flu shot for protection to begin.

Why do I have to get the flu shot every year?1,2

An annual flu vaccine is recommended because the flu virus is constantly changing, and a new vaccine is created each year in order to better match the strains predicted to be in circulation. In addition, the protection from the vaccine usually does not last longer than one year.

Is the flu vaccine safe?2,5

Yes. The flu vaccines currently available in Canada are generally well tolerated, with severe reactions to the vaccines being rare. Some people may experience local reactions, such as redness, tenderness, or swelling at the injection site, but these are usually mild and will subside in a few days.

Can the flu shot give you the flu?2

No. Flu vaccines either do not contain live viruses or only contain weakened versions of the viruses which cannot give you the flu.

Why is there thimerosal in the flu vaccine? Doesn’t that cause autism?2

In Canada, the multi-dose vials of flu vaccine contain thimerosal, a preservative which is used to keep the vaccine free of contamination. However, the quantities contained are minute and have not been found to be associated with autism. Thimerosal is not included in the single-use or nasal spray formulations of the flu vaccine.

Where can I get the flu shot?

You can get the flu shot from multiple healthcare providers including your doctor, nurse and pharmacist. Pharmacists can administer flu vaccine to individuals five years of age and older. Many pharmacies are open late and on weekends making it convenient for you to obtain your flu shot. Visit your local pharmacy and speak to your pharmacist about getting your flu shot today!


  1. Houser, K. & Subbarao, K. Influenza vaccines: challenges and solutions. Cell Host Microbe 17, 295–300 (2015).
  2. Government of Canada. Canadian Immunization Guide Chapter on Influenza and Statement on Seasonal Influenza Vaccine for 2019–2020. (2019). Available at: https://www.canada.ca/en/public-health/services/publications/vaccines-immunization/canadian-immunization-guide-statement-seasonal-influenza-vaccine-2019-2020.html. (Accessed: 15th July 2019)
  3. Skowronski, D. M. et al. Interim estimates of 2018/19 vaccine effectiveness against influenza A(H1N1)pdm09, Canada, January 2019. Eurosurveillance 24, 1900055 (2019).
  4. Immunize Canada. Read. Learn. Understand. Lower your flu risk (2018). Available at https://immunize.ca/sites/default/files/Resource%20and%20Product%20Uploads%20(PDFs)/Campaigns/Influenza/2019-2020/public_flu_factsheet_2019_web_e.pdf. (Accessed 15th July 2019)
  5. Government of Canada. Know the Flu Facts. (2016). Available at: http://healthycanadians.gc.ca/publications/diseases-conditions-maladies-affections/fact-sheet-flu-grippe-faits-feuillet/alt/fact-sheet-flu-grippe-faits-feuillet-eng.pdf. (Accessed 15th July 2019)
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