De-Bunking the Flu Vaccine

De-Bunking the Flu Vaccine

Written by: Hilary Van Klooster, BScPhm, RPh

Flu season will once again be upon us shortly. There is constant talk about vaccines in the news and social media. Understanding what is true can be difficult. The following aims to provide a little clarity on some myths about the flu vaccine.

Myth: I don’t need the flu shot every year.

Every year the flu vaccine is tailored to match the top three influenza virus strains causing illness that year. A flu vaccine one year may not protect a person the next year as the virus strains may have changed. Even if the vaccine has not changed from the year before, it is still recommended to get yearly vaccination as the immune response to the influenza vaccine declines quickly over time. Optimal influenza immunity is gained with yearly vaccination.

Myth: It is better to take the chance of getting the flu rather than getting the flu vaccine.

The risk-benefit scale of the influenza vaccines tips predominantly in favour of the vaccine. The risks associated with the flu, such as serious illness, hospitalization and potentially death, immensely outweigh the risks of the vaccine, including injection site reactions and allergic reaction.

Myth: I got the flu vaccine therefore I am guaranteed to not get the flu.

Unfortunately there are very few things that can be guaranteed these days and the flu vaccine is one of them. Although the flu vaccine has been proven to work there are still a few circumstances that may result in illness even after getting vaccinated. A person could potentially get infected with a strain that is very different from the expected top three virus strains for which the vaccine was produced that year. A person could also get infected with a virus other than influenza that may produce similar illness characteristics. The vaccination cannot protect against every single virus as there are too many and viruses are constantly changing and mutating. There is the possibility that a person can get infected with the flu virus right before they get vaccinated, before their body is able to produce an immune response against the virus as it takes a day or two to start showing symptoms. It takes approximately two weeks for our bodies to produce immunity against flu viruses after receiving the vaccine. Infection during these two weeks could also result in illness. Occasionally a person may not produce the expected immune response from a vaccine, such as the elderly or those with compromised immune systems. These people could still become ill despite adequate vaccination.

Myth: If I get 2 flu vaccines I will get twice the immunity.

For the average person, there is little to no evidence that suggests more than one vaccination annually is necessary. One vaccine is enough to produce an adequate immune response, even in those with weaker immune systems such as the elderly.

Myth: It’s now January so it’s too late to get the flu vaccine.

It is always recommended to get the flu vaccine earlier in the flu season to obtain the most benefit. However, January is not too late to still get vaccinated for the remainder of the flu season. Vaccinations undeniably follow the principle ‘better late than never’.

Myth: The flu vaccine will give me the flu.

Something that is said all too often when it comes to the flu vaccine is ‘I got the vaccine and it gave me the flu’. It is not possible for the vaccine to give you the flu. The flu vaccine is made with either inactivated or dead, non-infectious virus fragments, or through recombination which contains no virus at all. Whichever type of flu vaccine you get, there is no infectious material present and therefore no infection can occur. As stated before, there is the possibility to get infected right before or up to two weeks after vaccination before immunity is produced. Some people may also mistake a reaction to the vaccine as an infection. The usual side effects seen with the flu vaccine are pain and redness at the injection site. Low grade fever, headache, aches and muscle pain, although uncommon, are potential side effects of vaccinations and often get misinterpreted as the flu.

The flu can be a serious and potentially fatal illness. Protect yourself and those around you this year by getting your flu vaccine. For further information visit your friendly local pharmacists at Sinclair Pharmacy or visit to find out where you can get your free flu vaccine this season.


Province of Ontario website. Available at <>.

Centers for Disease Control and Prevention. Available at <>.