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Currently Approved Vaccines

mRNA Vaccines:

Pfizer-BioNTech & Moderna

  • Individuals 12 and older
  • Two doses of an mRNA vaccine is required*
  • Pfizer-BioNTech: Individuals in Ontario 12 (or turning 12 in 2021) and older are eligible to receive the vaccine.
  • Moderna: Individuals in Ontario 18+ are eligible to receive the vaccine.

Viral Vector Vaccines:

AstraZeneca & Janssen (Johnson & Johnson)

  • Individuals 18 and older
  • Janssen: One dose series
  • AstraZeneca: Requires a second dose of AstraZeneca or an mRNA vaccine*

Two mRNA and two viral vector COVID-19 vaccines have been approved by Health Canada and are used to prevent COVID-19. View Health Canada’s authorized vaccines for COVID-19. Before any vaccines are available in Ontario or Canada, they undergo large clinical trials to determine if they are safe and effective. Health Canada has maintained the same quality standards for review and approval of COVID-19 vaccines as were in place before the pandemic.

COVID-19 vaccines are free for anyone living in Ontario. The vaccine is strongly recommended to keep yourself and the community safe.

If you received a first dose of an mRNA vaccine, you can safely receive either of the mRNA vaccines as your second dose. If you received a first dose of AstraZeneca, you can safely receive AstraZeneca or an mRNA vaccine as your second dose. For more information, view Safe and Effective Second Dose Information. Available in French.

Please note – As of May 11, 2021, first dose administration of the AstraZeneca COVID-19 vaccine has been paused in Ontario.

Visit the Health Canada website for a full list of drugs and vaccines that have been authorized for treating and preventing COVID-19. 

What Does It Mean to Be Fully Vaccinated?

In Ontario, an individual is considered fully vaccinated if they have received:

  • The full series of a COVID-19 vaccine authorized by Health Canada or any combination of such vaccines;
  • One or two doses of a COVID-19 vaccine not authorized by Health Canada, followed by one dose of a COVID-19 mRNA vaccine authorized by Health Canada; or
  • Three doses of a COVID-19 vaccine not authorized by Health Canada; and
  • They received their final dose of the COVID-19 vaccine at least 14 days ago.

How Do the Vaccines Work?

Vaccines work by teaching your immune system how to produce antibodies that prevents you from becoming sick if you are exposed to the virus in the future. The vaccine provides your body with something that looks like the virus so that your immune system can learn to identify the virus and produce specific antibodies to fight the virus, without exposing you to the virus that causes COVID-19. All four of the vaccines are administered by injection as a needle in the upper arm.

The mRNA vaccines use a method called messenger RNA (mRNA) which acts as a code that tells your cells how to make a piece of the outer lining of the virus, for a short period of time. This piece of the virus is enough for your immune system to learn how to recognize and be ready to fight off the virus, but it cannot make you sick.

The viral vector vaccines are slightly different in that they use a harmless non-replicating viral vector, which produces components of the outer lining of the virus. These will not cause COVID-19 infection, but it remains in the body long enough to build an immune response to the virus. 

Public Health Ontario:

How effective are the Vaccines?

All COVID-19 vaccines approved by Health Canada are safe and effective against COVID-19. The best way to prevent COVID-19 infections, hospitalizations, and deaths in Canada is to increase population immunity. The more people who receive vaccines, the more we will be able to reduce or prevent community spread.

All four approved vaccines are effective at preventing severe, symptomatic infection with COVID-19. Immunity may take up to 14 days to develop, and individuals vaccinated will still be required to follow public health measures.

It is very important that you complete the full vaccination series to protect yourself completely against COVID-19. You will be at risk of contracting COVID-19 until you complete the full vaccination series. Most COVID-19 vaccines require two doses to complete the series (except the Janssen vaccine). The first dose of the vaccine trains your body to recognize the virus and the second dose prolongs the duration of protection.

More information on vaccines in Canada, and vaccine authorization updates from the Government of Canada.

Third Doses of COVID-19 Vaccines

A complete two-dose COVID-19 vaccine series provides strong protection against COVID-19 infection and variants of concern in the general population. Based on suboptimal/waning immune response to vaccines and increased risk of COVID-19 infection, a third dose may be required to provide sufficient protection to select populations. Learn more about third doses in Ontario and Third Dose Recommendations.


National Advisory Committee on Immunization (NACI) – Recommendations on the use of COVID-19 vaccines

Ministry of Health - COVID-19 Vaccine Information Sheet - Available in other languages

Health Canada – Pfizer-BioNTech COVID-19 Vaccine

Health Canada – Moderna COVID-19 Vaccine

Health Canada – AstraZeneca COVID-19 Vaccine

Health Canada – Janssen COVID-19 Vaccine

Information about COVID-19 Vaccines Available in Canada:

The facts about COVID-19 vaccines

Pfizer-BioNTech COVID-19 vaccine: What you should know

Moderna COVID-19 vaccine: What you should know

AstraZeneca COVID-19 vaccine: What you should know

Janssen COVID-19 vaccine: What you should know

Product Monographs:

Product Monograph – Moderna COVID-19 Vaccine

Product Monograph – Pfizer-BioNTech COVID-19 Vaccine

Product Monograph – AstraZeneca COVID-19 Vaccine

Product Monograph – Janssen COVID-19 Vaccine


COVID-19 vaccine resources supporting individuals with developmental disabilities, families and caregivers by Connectability

First Nations, Inuit and Métis perspectives and knowledge sharing on COVID-19 vaccines by Women’s College Hospital, Maad'ookiing Mshkiki – Sharing Medicine

Dr. Onye Nnorom talks about her thoughts on the COVID-19 vaccine by the Black Health Alliance

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Last modified: 
Tuesday, September 21, 2021 - 12:14pm