Influenza (flu)

Why the seasonal flu shot is required for placement, how it protects you and your patients, and the record you need to submit each year.

Status: Required for all students

Valid for: One influenza season — a new dose and new proof are required each year.

This page explains why the seasonal flu shot is required and how it works, using guidance from Health Canada and the Public Health Agency of Canada. It is educational and does not replace advice from your own health care provider or the specific rules of your program and placement site. See the Source & references at the bottom.

Why this is required

As a medical student on placement you are in close contact with patients who are at high risk of severe influenza — older adults, newborns, pregnant patients and people with chronic conditions. Health Canada considers annual influenza vaccination an essential component of the standard of care for all health care workers.

Protects you. The flu shot lowers your own risk of getting sick during a busy placement.
Protects your patients. Vaccinating health care workers reduces the risk of transmitting influenza to patients at high risk of severe outcomes.
Keeps you working. Fewer infections means fewer missed placement days and less strain on the clinical team.

Health Canada recommends the seasonal flu vaccine annually for everyone 6 months of age and older who has no contraindication, so getting it also protects your own household and community.

About influenza (the flu)

Influenza is a respiratory infection caused by influenza A and B viruses, which cause seasonal epidemics each year. It spreads by aerosols and droplets from coughing or sneezing, and through contact with respiratory secretions. The incubation period is usually about 2 days, and adults can spread it from about a day before symptoms start to roughly 5 days after.

Symptoms usually come on suddenly: fever, cough and muscle aches, often with headache, chills, loss of appetite, fatigue and sore throat.
Complications can include pneumonia, respiratory failure, cardiovascular complications and worsening of underlying chronic conditions; infection is also linked to a higher risk of heart attack and stroke in the first 15 days.
Global burden: the World Health Organization estimates 3 to 5 million cases of severe illness and 290,000 to 650,000 deaths from influenza each year.

How the vaccine works

Most flu vaccines contain inactivated (killed) influenza viruses that cannot cause the flu; they teach your immune system to recognise the strains expected to circulate that season. Protective antibodies develop about two weeks after vaccination. Health care workers are advised to receive a non-live (inactivated) vaccine; a live nasal-spray vaccine (LAIV) also exists but is generally not used for HCWs. In Canada the seasonal vaccine is trivalent — covering an A(H1N1) strain, an A(H3N2) strain and a B strain — and higher-dose or adjuvanted versions are offered to help protect adults 65 and older.

How well it works

Effectiveness varies from season to season, depending on how well the vaccine strains match the viruses actually circulating and on your age and health.
Even in a season with a less-than-ideal match, vaccinated people — especially those at high risk of complications — are still more likely to be protected than people who are unvaccinated.
Getting vaccinated in consecutive seasons does not reduce how well the vaccine works.

Safety and side effects

Reactions are usually mild and short-lived:

Soreness at the injection site, typically lasting up to two days
Systemic reactions such as muscle aches, headache, fatigue or malaise

Serious adverse events are rare. Guillain-Barré syndrome has been estimated at about 1 excess case per million doses — lower than the risk of Guillain-Barré from influenza illness itself. People with an egg allergy can safely receive any influenza vaccine, at the full dose and without prior skin testing.

Staying protected

Because the circulating strains change and immunity fades within a year, a new dose is needed every influenza season. Vaccination before the season starts (in the fall) is strongly preferred, though the vaccine can still be given later in the season. The flu shot can be given on the same day as your COVID-19 vaccine or any other routine vaccine. Confirm the timing that applies to you with your program or a health care provider.

What to submit

An official record or receipt for this season's influenza vaccine
The vaccine product name and the date it was given
Your full legal name and date of birth

Accepted proof

Pharmacy immunization receipt
Clinic, public health or provincial immunization record
Occupational or student health record of your flu shot
International immunization record with an English translation

Good to know

Last season's flu shot does not count — proof must be for the current influenza season.
Get it early in the fall so your record is ready before your placement start date.
If your site runs on-site flu clinics, keep the receipt they give you.
Declination policies differ — some sites require you to wear a mask for the season if you opt out, so check your program's rules.

Validity

Valid for one influenza season. You will need a new dose, and new proof, each year.

Source & references

The medical information on this page is adapted from Health Canada and the Public Health Agency of Canada:

Influenza (flu)

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