Answers to common questions about the flu shot

The latest scientific evidence and guidance from experts is that COVID-19 vaccines can be given at the same time—or any time before or after—other vaccines, including the flu shot, in adults and children over 5 years of age.^1,8

During the 2021/22 and 2022/23 flu seasons, Canada did not see very many cases of the flu for a couple of reasons:
- More people got the flu shot. In fact, the percentage of people getting the flu shot seems to be increasing every year.³
- We had a lot of measures in place to help curb the spread of COVID-19, including stay-at-home orders, social distancing, increased handwashing and masking. These helped reduce the spread of germs and lowered the chances of flu spread as well.⁵ However, as masking and social distancing rates declined in spring 2022, a spike in flu cases was seen.⁴
It is important to receive your flu shot every year, regardless of what happened the previous year. With fewer public health restrictions in place, your chances of encountering someone with the flu increases.
It is also important to get your flu shot to protect others and to try to reduce the strain on our health-care system, which is already strained by COVID-19 and a shortage of health workers.

Yes, you still need your flu shot! COVID-19 and the flu are caused by 2 different viruses.6 It is important to be vaccinated for both COVID-19 and influenza to help protect yourself, as well as others, from both viruses.⁷
Both COVID-19 and the flu can cause mild to life-threatening infections. There is an increased risk of severe complications from the flu for those who are younger than 5 years of age, older than 65 years of age, pregnant, or who have chronic diseases or weakened immune systems.⁸

Wearing a mask and social distancing help to reduce the risk of virus transmission, but it’s still possible to spread a virus even with these precautions in place.⁵
By receiving the flu shot, you are helping to protect yourself and others.8 It’s also important to get vaccinated against the flu to help reduce the ongoing strain on our health-care system due to COVID-19.⁷

The most common side effect from the flu shot is discomfort at the site of the injection (sore arm). This may include pain, swelling and/or redness.8 This is temporary and goes away in a day or 2. Some individuals may also experience nasal congestion and a runny nose.⁸
The most common serious reaction is an allergic response to one of the components of the vaccine.8 It is important to notify your pharmacist if you have a known allergy to any components of the influenza vaccine before receiving the shot.
After you receive your vaccine, it is important to wait for a set time (recommended by your pharmacist or health-care provider) to ensure that you are properly monitored for any signs of an allergic reaction.⁸

The flu is different from the common cold. Colds and the flu are caused by different viruses. While the symptoms of both may be similar, the flu typically has a more rapid onset and the symptoms are usually more severe.⁶
For flu, common symptoms include fever, cough and muscle aches. In children, nausea, vomiting and diarrhea are also common.⁶
For a cold, common symptoms usually include a runny and congested nose. It is rare to have a fever with a cold.⁶ Unlike the flu, colds usually do not lead to more serious health problems like pneumonia or hospitalization.⁶

Even if you are young and healthy and may not experience any severe symptoms from the flu, you can still transmit the flu to others, especially those who are high risk.⁸ People at high risk include the elderly, children, pregnant people, and those who have weakened immune systems.⁸
It is important to get your flu shot to help protect those in your community who are at higher risk of severe illness from the flu.

When creating the annual flu vaccine, scientists predict which flu strains are going to be most common that year.^5,8 The effectiveness of the vaccine will depend on which strains of influenza actually do become most common.⁸
Some years, the prediction may be a little off, resulting in influenza infections that aren't covered by the vaccine.⁸ In this situation, there may be more cases of the flu compared to the previous year even though many people are vaccinated.

Yes. People who are pregnant are at high risk of experiencing severe symptoms from the flu, and this is dangerous for both the pregnant person and the baby. It is recommended that pregnant people receive the inactivated influenza version of the vaccine, which is available only by injection. The nasal spray is not recommended.⁸
The inactivated influenza vaccine is approved and considered safe to use when breastfeeding.⁸

References:

COVID-19 vaccine: Canadian Immunization Guide. Government of Canada web site. Updated August 25, 2023. Accessed September 5, 2023.
Sulis G, Basta NE, Wolfson C et al. Influenza vaccination uptake among Canadian adults before and during the COVID-19 pandemic: An analysis of the Canadian Longitudinal study on Aging (CLSA). Vaccine. 2022;40(3):503-11.
FluWatch report: June 19 to July 23, 2022 (weeks 25-29). Government of Canada web site. Updated July 29, 2022. Accessed August 25, 2022.
Frequently Asked Influenza (Flu) Questions: 2022-2023 Season. Centers for Disease Control and Prevention web site. Updated 2022. Accessed September 6, 2023.
The difference between cold and flu. Centers for Disease Control and Prevention web site. Updated 2022. Accessed September 5, 2023.
Guidance on the use of influenza vaccine in the presence of COVID-19. Government of Canada web site. Updated 2021. Accessed February 6, 2023.
Statement on seasonal influenza vaccine for 2023-2024. Government of Canada web site. Updated 2023. Accessed September 5, 2023.