A flu shot is a vaccine designed to help your immune system recognize and fight the influenza viruses most likely to be circulating that season. Getting a flu shot each year reduces your chances of getting sick, lessens severity if you do get sick, and protects others in the community.
How does the flu shot work?
The flu vaccine works by safely exposing your immune system to the proteins of an inactivated or weakened influenza virus. This trains your body to recognize and produce targeted antibodies to fight off the infection, leaving you prepared with memory cells in your immune system that will recognize and destroy the virus if you’re exposed later in the year.
You can’t get the flu from the flu vaccine. However, mild reactions like a sore arm, tiredness, or low-grade fever can happen. It takes about two weeks for your body to build up enough antibodies to provide immunity.
Who should get vaccinated?
In Canada, it’s typically recommended that everyone 6 months and older get a flu shot every year. However, those with the greatest risk of being severely impacted or hospitalized due to the flu include:
- Adults 65+
- Young children
- Pregnant people
- People with chronic health conditions (like asthma, diabetes, heart disease)
Your healthcare provider can help you decide if the flu vaccine is right for you – and which flu vaccine is best for you, especially if you’re older or have specific medical conditions.
How often do I need a flu shot?
Flu viruses mutate quickly. To match these evolving strains, global health organizations (like the World Health Organization) adjust and update the flu vaccine’s formula every year. Flu vaccine effectiveness varies year to year, depending on how well the vaccine strains match circulating viruses and on individual factors, like age and immune status.
Even if you still catch the flu after being vaccinated, your antibodies help your body fight it off faster and significantly reduce the severity of your symptoms, lowering your risk of hospitalization.
Habits like working out and regularly washing your hands can also help keep you healthy. Learn more about how to build a routine.