Frequently asked questions about influenza vaccines

print this page
Why should I get vaccinated against influenza?

Getting vaccinated is the best way to protect against influenza, a serious and sometimes fatal infection. In Canada, thousands of people are hospitalized and may die from influenza and its complications during years with widespread or epidemic influenza activity. Influenza can lead to serious illness in seniors over 65 years and in other high-risk groups. Even healthy people can get very sick from influenza. When you get vaccinated, you help protect others as well by reducing the spread of the influenza virus. 

Is it more important this year to get vaccinated against influenza?

Yes! Getting an influenza (flu) vaccine is more important than ever during the 2020/21 flu season, to protect yourself and the people around you from flu, and to help reduce the strain on the healthcare system responding to the COVID-19 pandemic. The symptoms of COVID-19 and flu can be similar and make people sick enough that they have to go to the hospital. By getting your flu shot, you can help the health care system keep resources available to help those with COVID-19. Getting a flu shot every year is the best way to protect yourself against flu, and its serious complications. It is also important to make sure you wash your hands regularly, avoid touching your eyes, nose and mouth and being around sick people. And remember, if you don't feel well, stay home.

How do influenza vaccines work?

Influenza vaccines cause antibodies to develop in the body about two weeks after vaccination. These antibodies provide protection against infection with the viruses that are in the vaccine. Learn more about how vaccines work in our how do vaccines work section

Influenza vaccines are designed to protect against the influenza viruses that research indicates will be most common during the upcoming influenza season. "Trivalent" influenza vaccines are made to protect against three different influenza viruses, and "quadrivalent" vaccines are made to protect against four different influenza viruses. 


Why do I need an influenza vaccine every year?
An influenza vaccine is needed every year for two reasons:
1. Influenza viruses are constantly changing, so each year, the viruses used to make the vaccine change to protect you against the viruses circulating that year.
2. Protection from the influenza vaccine declines over time. 
What viruses do the 2021/22 influenza vaccines protect against?
  • A/Victoria/2570/2019 (H1N1)pdm09-like virus
  • A/Cambodia/e0826360/2020 (H3N2)-like virus
  • B/Washington/02/2019-like virus and
  • B/Phuket/3073/2013-like virus 

The A/Victoria and A/Cambodia strains were not contained in the 2020/21 season vaccines.

Who should get vaccinated against influenza?

Canada's National Advisory Committee on Immunization recommends that everyone 6 months of age and older get an influenza vaccine, with rare exception. Some people are at high risk of serious illness from influenza, such as children 6 months to less than 5 years of age, pregnant women, seniors 65 years and older and people with certain medical conditions. Vaccination is especially important for these people.

Who is eligible for a free influenza vaccine?

In B.C., the influenza vaccine is provided free to people who are at high risk of serious illness from influenza (such as young children, pregnant women, the elderly and people with certain medical conditions), those able to transmit or spread influenza to those at high risk and people who provide essential community services.

For a list of people eligible for the free inactivated influenza vaccine, see the HealthLinkBC File: Inactivated Influenza (Flu) Vaccine.

Anyone not eligible for a free influenza vaccine can buy it at most pharmacies and travel clinics. Some employers also provide free vaccines to employees.

Are influenza vaccines safe for pregnant people?

The inactivated influenza vaccine (flu shot) is considered safe at any stage of pregnancy. Pregnant people, or those intending to become pregnant, should receive the inactivated influenza vaccine (flu shot), which contains killed influenza viruses that cannot cause infection.

People in the second half of pregnancy are at higher risk of influenza-related complications and at higher risk of hospitalization from these complications, especially those in the third trimester. As well, people at any stage of pregnancy who have chronic medical conditions are also at higher risk of serious influenza complications and should be immunized.

Visit our pregnancy section to learn more about vaccines and pregnancy. 


When should I get vaccinated?

The influenza season in Canada generally runs from November through April. In B.C., influenza vaccines are usually available starting in October. Although you can receive this vaccine at any time during the influenza season, for best protection, you should get immunized as early as possible.

Where can I get an influenza vaccine?

Influenza vaccines are provided at a wide variety of locations across the province including:

  • Public health clinics
  • Pharmacies (pharmacists can immunize people 5 years of age and older with injectable vaccine and 2 years and older with nasal spray influenza vaccine)
  • Doctors’ offices
  • Travel clinics

Services vary by location. You can use our Influenza (Flu) Clinic Locator to find an influenza vaccine clinic near you.

How well do influenza vaccines work?

The influenza vaccine is the best way to protect against influenza. How well the vaccine works varies from season to season. It depends on how well-matched the influenza vaccine is with the viruses circulating during the season and on the health and age status of the person being vaccinated. When the influenza vaccine is well matched with the circulating viruses, it prevents influenza in about 60% to 80% of adults and children receiving the vaccine. It is less effective in elderly adults, but studies have shown that the influenza vaccine decreases the incidence of pneumonia, hospital admissions, and death in the elderly population.

Can influenza vaccines give me influenza?

The inactivated influenza vaccine (flu shot) cannot give you influenza. This vaccine contains killed influenza viruses that cannot cause infection.

Date last reviewed: 
Friday, Sep 03, 2021