Influenza vaccine

Influenza (or “flu”) is a respiratory infection caused by influenza virus. Influenza outbreaks happen every year.

Influenza vaccination is safe for anyone 6 months of age and older. It protects you and those around you from the flu and its complications. Because influenza viruses change – often from year to year – people don’t stay immune for very long. Flu shots are usually given once a year starting in October. The shots provide protection throughout the flu season — October to April.

Should my child get a flu shot?

Yes. All children over 6 months old should get a flu shot each year.

Babies and children 6 months to 9 years of age who have never had a flu shot will need 2 doses of the vaccine, given at least 4 weeks apart. 

Those who have had one or more doses of the regular seasonal flu shot in the past, or children 9 years of age and older, will only need 1 dose per year.

The vaccine is especially important for children and youth who are at high risk of complications from the flu, including those who:

• are between 6 months and 5 years of age.
• have chronic heart or lung disorders (such as bronchopulmonary dysplasia, cystic fibrosis, asthma) serious enough to need regular medical follow-up.
• have chronic conditions that weaken the immune system, such as immune deficiencies, cancer, HIV or a treatment that causes immune suppression.
• have diabetes or other metabolic diseases.
• have chronic kidney disease.
• have chronic anemia or a blood disorder.
• have a chronic neurological or neurodevelopmental disorder.
• are severely obese (body mass index ≥40).
• are pregnant.
• have to take acetylsalicylic acid (ASA or Aspirin) on a daily basis.
• live in a chronic care facility.
• live in First Nation or Inuit communities.
• live with another child or adult who is at risk of complications from the flu.

Children under 5 years old are at higher risk of complications from the flu – such as high fever, convulsions and pneumonia. If you have children younger than 5 years old or who have health complications, everyone living in the house should get a flu shot. This is especially important if you have children under 6 months old or if a member of your household is pregnant. 

Caregivers who take care of children less than 5 years of age should also be immunized.

How safe is the flu vaccine?

The influenza vaccine is very safe. It cannot cause the flu. Side effects are usually mild and can include:

• mild soreness where the needle went into the arm for 1 to 2 days.
• a mild fever or aches for the first day or 2 after immunization.

Do not give your child ibuprofen or acetaminophen before or around the time of vaccination as it does not prevent the pain of injection and it could have an impact on how well the vaccine works. These medications can be used to treat fever, pain, or other bothersome side effects if they develop after vaccination.

Can my child get the flu vaccine at the same time as another childhood vaccine, including the COVID-19 vaccine? 

Yes. It is safe to get the seasonal flu vaccine (shot or nasal) at the same time as (or any time before/after) any childhood vaccine, including the COVID-19 vaccine. Many children are behind with their childhood vaccines or boosters because of the COVID-19 pandemic and getting the vaccines at the same time can help them catch up more quickly.  

For children 5 to 11 years old, it may be best to wait at least 14 days between the COVID-19 and other vaccines. The reason for this is that if any side effects happen, doctors will know which vaccine they are related to. But only space out vaccines if you are sure that no other vaccines your child needs will be given late. 

I’m pregnant. Is it safe to get the flu shot?

Yes, the flu shot is safe. Those who are pregnant should be immunized. Infants born during flu season to mothers who got a flu shot are usually protected against the flu for a few months. The flu shot is also safe and highly recommended for those breastfeeding. Since infants less than 6 months of age cannot get the flu shot (it won’t work), antibodies against the flu are transferred through breast milk. 

Who should NOT get the flu shot?

Very few children should NOT get a flu shot:

• Babies under 6 months of age. Although the vaccine is not harmful to babies less than 6 months old, it does not work.
• If your child has a serious allergy to thimerosal (a preservative in contact lens solutions and the flu vaccine), a thimerosal-free vaccine should be given.

The influenza vaccine is safe for individuals with an egg allergy. 

What is the nasal flu vaccine (FluMist)?

This type of flu vaccine (brand name: FluMist) is given as a nose spray instead of injection. Healthy children over the age of 2 can get the nasal flu vaccine. If your child has a chronic condition or illness, you should speak to your doctor to find out if the nasal flu vaccine is appropriate. The vaccine is given in 1 or 2 doses. Each dose is one squirt into each nostril.

• If your child is under 9 years of age and has received any flu vaccine before, they will only need 1 dose.
• If your child is under 9 years of age and hasn’t received a flu vaccine before, they will need 2 doses, given at least 4 weeks apart.

This type of flu vaccine is not covered by all provincial or territorial health plans, which means you may have to pay for it.

Who should not get the nasal flu vaccine?

• Children less than 2 years old (vaccine may cause wheezing).
• Those who are pregnant and people who have weakened immune systems. It is a live (weakened) virus vaccine.
• People who have to take acetylsalicylic acid (ASA or Aspirin) on a daily basis.
• People with severe asthma who have been treated with steroids or had severe wheezing in the past 7 days (the vaccine may make the wheezing worse).

These people should get the injected vaccine.