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About the COVID-19 vaccines

We’re ensuring you have access to safe and effective vaccines against COVID-19.

The Government of Canada is carefully reviewing all the scientific data and evidence for the vaccines, working on distribution plans, and accelerating purchases of the vaccines.

Health Canada has evaluated, licensed and approved the following COVID-19 vaccines for use in Canada:

All approved COVID-19 vaccines are effective. The vaccines are free with no cost to the public. The approved vaccines do not contain any animal-derived ingredients.

Learn more about the COVID-19 Vaccine Approval Process and Safety from the Ministry of Health.

How the vaccines work

The COVID-19 vaccines are given by an injection into the muscle of the arm. For the vaccine to work best, you need to get 2 doses. The vaccines are very effective at preventing COVID-19 symptoms in people who get it. You cannot get COVID-19 from the vaccine.

If you get vaccinated and are exposed to COVID-19, it's not yet known if you can still give the infection to someone that has not been immunized. That's why, even after being vaccinated, it's important to continue to practice the Core Four to prevent the spread of COVID-19.

The COVID-19 vaccines are messenger RNA vaccines, often called mRNA vaccines. mRNA vaccines teach our cells to make a protein that triggers an immune response. Our cells break down and destroy the mRNA after the protein has been created.

mRNA vaccines do not use the live virus that causes COVID-19 infection, and they do not enter the part of the cell where our DNA is stored. The vaccine cannot alter your DNA in any way.

Learn more about COVID-19 mRNA vaccines.

COVID-19 vaccine effectiveness

Based on studies of approximately 44,000 participants, the Pfizer-BioNTech COVID-19 vaccine was 95% effective in preventing COVID-19 beginning 1 week after the second dose. This means that people may not be fully protected against COVID-19 until at least 7 days after the second dose.

Based on studies of approximately 30,000 participants, the Moderna COVID-19 vaccine was 94% effective in preventing COVID-19 beginning 2 weeks after the second dose. This means that people may not be fully protected against COVID-19 until at least 14 days after the second dose.

There is no current evidence to suggest that the approved vaccines will be any less effective against the new COVID-19 variant.

Other information

The Pfizer-BioNTech mRNA vaccine can be given to anyone aged 16 years and older. The Moderna COVID-19 vaccine can be given to anyone aged 18 years and older.

The safety and effectiveness of the vaccines in people younger than 16 or 18 years of age has not yet been established.
If you've previously had COVID-19, you're still encouraged to get the vaccine because it's not known how long immunity lasts after being infected with the virus.

Precautions for certain groups

You should not receive a COVID-19 vaccine without consulting your health care provider if you:

  • Have a compromised immune system or an autoimmune condition.
  • Are pregnant or trying to get pregnant.
  • Are breastfeeding.
  • Are under 16 years.

There's limited information about the use of COVID-19 vaccines in these groups because they were not included in the clinical trials. Information may continue to evolve as further evidence becomes available.

Additional precautions are required in some cases. Consult your health care provider before getting vaccinated if you have:

  • Experienced a serious allergic reaction (including anaphylaxis) to another vaccine, drug, or food.
  • A bleeding disorder.

Do not get the vaccine in the following situations:

  • If you're allergic to any component of the vaccine.
  • If you had an allergic reaction to a previous dose of the vaccine.

Wait to get the vaccine if you're sick, have COVID-19 or symptoms of COVID-19, or have received other vaccinations in the past 2 weeks.

Like all vaccines, some people may experience side effects from the COVID-19 vaccine. These side effects will likely be mild to moderate and resolve after a few days. They include pain at the injection site, headache, fatigue, muscle and joint pain, chills and fever. Some of these side effects are part of the body’s response to developing immunity.

Serious side effects after receiving the vaccine are rare. If you develop any serious symptoms or symptoms that could be an allergic reaction, seek medical attention right away.

Symptoms of an allergic reaction include:

  • Hives (bumps on the skin that are often very itchy)
  • Swelling of the face, tongue, or throat
  • Difficulty breathing

If you experience a severe allergic reaction, call 911 or go to the nearest hospital.

It's important to follow up with your health care provider if you experience serious side effects. Health care providers can find information on reporting an adverse event on the Health Professionals page.