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Influenza (The Flu) Vaccines - Frequently Asked Questions

The following are frequently asked questions about the flu vaccine.

What is the flu vaccine?

  • An immunization made each year to protect against strains of influenza virus that are expected to be circulating in the community in the up-coming influenza season.
  • The vaccine stimulates your body’s immune system to build antibodies against influenza, making it stronger and ready to fight off the illness before it starts.
  • Free flu vaccine for people 6 months and older provides protection against four (QIV) common strains of the flu virus.
  • A high-dose trivalent (TIV) vaccine has been approved in Canada for those 65 years of age and older, however the National Advisory Committee on Immunization has not identified any preference high-dose TIV and QIV products.

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What is the best vaccine for my child?

  • The expert advisory committee on vaccines in Canada (National Advisory Committee on Immunization (NACI) recommends that children 6 months through 17 years receive a vaccine that protects against four stains of flu virus.
  • The traditional vaccine injection given in the arm is safe and works well to prevent influenza infection in children.
  • If you would prefer your child not have a needle, a nasal spray alternative called FluMist is also available and free for children age 2 through 17 years
  • For more information, view the Nasal Spray Flu fact sheet (PDF file).

Is the vaccine safe? What are the side-effects?

  • The flu vaccine is safe. Most people who get the vaccine have either no or mild side effects.
  • Mild side-effects (occur within 1 - 2 days after vaccination)
    • soreness
    • redness or swelling at the injection site
  • Life-threatening allergic reactions are very rare.
  • In very rare cases the flu vaccine has been associated with:
    • Guillain-Barré Syndrome (GBS)
      • GBS is a very uncommon disease that causes muscle paralysis.
      • The risk is about one in one million doses of vaccine given.
    • Ocular respiratory syndrome (ORS)
      • In 2000-2001, a small number of people who received the influenza vaccine developed ORS.
      • ORS can cause red eyes, cough, chest tightness, difficulty breathing, hoarseness, sore throat and swelling of the face. 
      • Symptoms occur within 24 hours and resolve within 48 hours.
      • Persons who experienced ORS in the past may safely have the flu vaccine but should talk to their health care provider before being immunized.

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How well does the vaccine protect against the flu?

  • Influenza vaccine effectiveness can vary from year to year and among different age and risk groups.
  • Remember the influenza vaccine cannot protect you from other types of viruses circulating in the fall/winter months that can cause illness much like influenza.
  • The body needs 2 weeks to build up protection to the flu virus after you receive your immunization and protection may last up to 1 year.

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Who should get the vaccine? 

  • The National Advisory Committee on Immunization (NACI), which advises the Public Health Agency of Canada, recommends the flu vaccine for everyone 6 months of age and older.
  • It is especially recommended for persons:
    • at high risk for complications of flu
    • who may spread influenza to high-risk people
    • who provide essential community services

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Who should not get the vaccine?

  • The Health Department will not give the vaccine at our clinics to anyone who:
    • has had severe allergic reaction to a past influenza vaccine such as:
      • hives
      • throat, and/or tongue swelling
      • difficulty breathing or shock
    • has a severe allergy to any part of the vaccine except egg
    • has a new or worsening illness, with or without fever (however, if you have a cold or other minor illness, you can still be immunized.)
    • has had Guillain-Barré Syndrome within 6 weeks of a past influenza vaccine
    • has had Oculorespiratory syndrome with lower respiratory symptoms
    • is under 6 months of age
  • If you fall into any of the above categories, depending on the situation, you may need to speak with your physician, or return after an appropriate time interval.
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When is the best time to get the vaccine?

  • Between October and mid-November each year.
    • It is recommended to receive the vaccine before influenza reaches the community but it can be given even after there is influenza activity.
  • It is also recommended for travellers to destinations where influenza is likely to be circulating.

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How many doses of the vaccine do I need?

  • Adults should receive 1 dose of the vaccine every year.
  • Children under 9 years of age who have never received a seasonal influenza immunization should receive 2 doses of vaccine given at least 4 weeks apart.
    • They are then recommended to receive 1 dose per year thereafter.

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When should I seek medical attention after receiving a vaccine?

  • As with other vaccines, we ask that you stay for at least 15 minutes after receiving your immunization.
  • You should seek medical attention if you experience the following:
    • swelling of the lips, tongue, or face
    • trouble breathing
    • hives
    • convulsions
    • dizziness
    • lasting or worsening weakness
    • high fever (40°C or 104° F)
  • Contact your family doctor or go to the nearest emergency room right away if you have any of these symptoms within 3 days of getting the influenza vaccine.

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Who should I talk to if I have more questions?

  • Speak to your health care provider.
  • Call 311.

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Your record of protection - After you get your immunization, you will be given a written record. Tell your doctor the date you received the influenza vaccine.