COVID-19: Vaccine Eligibility & Doses

A primary series is typically the first two or three doses, with the original (monovalent) mRNA vaccines, needed for a strong initial immune response.

Everyone aged 6 months and older is currently eligible to receive a COVID-19 vaccine. Children must be at least 6 months old at the time of vaccination. The original (monovalent) COVID-19 mRNA vaccines, Pfizer BioNTech  and Moderna Spikevax, are the best vaccine choices because of the strong immune protection they provide against severe illness and hospitalization, and their well-known safety profiles.

The Pfizer-BioNTech, Moderna Spikevax, Novavax Nuvaxovid and AstraZeneca/COVISHIELD vaccines require two doses. Janssen Jcovden (Johnson & Johnson) vaccine requires one dose to complete a primary series. For children 6 months to under 5 years of age, the Pediatric Pfizer (3 mcg) vaccine requires three doses.

For children ages 6 months to 4 years old, there is no preferred vaccine as both of the original mRNA products will provide strong protection against COVID-19 and its variants.

Children/youth, 17 years of age or younger, should talk about the benefits and risks of getting the vaccine with a parent or trusted adult.

The Novavax COVID-19 vaccine (protein subunit vaccine) is an option for people 12 years of age and older, who have not been able, due to contraindications, or are not willing to receive an mRNA COVID-19 vaccine. It can also be used to complete a primary series that was started using a viral vector vaccine.

The Janssen COVID-19 vaccine (viral vector vaccine) is an option for people 18 years of age and older, who are not able or willing to receive either a mRNA or Novavax vaccine. Informed consent is required. This vaccine requires one dose to complete a primary series.

Interval between doses

To further improve protection and effectiveness of the vaccine, the National Advisory on Immunization (NACI) and the Ministry of Ontario has recommended 8 weeks as the optimal interval between doses in the primary series. Evidence will continue to be monitored and information will be updated as needed.

Learn more about the administration of the COVID-19 vaccine, information about the vaccines, vaccine use by age, and where to get vaccinated.

Some people who have weakened immune systems may have a lower antibody response to the two or three-dose series due to their underlying condition(s). Getting three or four doses of the COVID-19 vaccine, as part of your first COVID-19 vaccine series, is recommended for people who are moderately to severely immunocompromised to help build antibodies and for better long-term protection.

It is important to speak with your doctor or specialist about the timing for you to have the best possible immune response from the vaccine and minimize delays in your treatment and advise the health care provider giving you the vaccination that you are immunocompromised.

A third or fourth dose of the original (monovalent) vaccine can be given at a minimum of two months (56 days) after the previous dose.

• For children ages 6 months to 4 years old, the monovalent Moderna (25mcg) is preferred and recommended by NACI. This will allow children to complete their primary series after three doses instead the four doses needed with the monovalent Pfizer-BioNTech (3mcg).
• For children ages 5 to 11 years old, the pediatric Pfizer-BioNTech (10mcg) vaccine should be given.
• For ages 12 to 29 years old, Pfizer BioNTech (30mcg) is recommended and preferred. With informed consent, adults 18 to 29 years old may receive a full dose of Moderna (100mcg).
• For ages 30 and older, a full dose of Moderna (100mcg) or PfizerBioNTech (30mcg) should be given.

A COVID-19 booster is a vaccine dose given after you have completed the primary vaccine series. It helps improve protection against COVID-19 that may have decreased over time and boosts the immune response even if you had a COVID-19 infection in the past. Health Canada authorized mRNA vaccines (Pfizer-BioNTech and Moderna Spikevax), Novavax Nuvaxovid (protein subunit vaccine), and Janssen (Johnson&Johnson – viral vector vaccine) as booster doses regardless of which vaccine was used for your primary series.

The interval between the doses depends on the vaccine you receive, your age, your health status and if you recently had a COVID-19 infection.

Booster dose eligibility

The bivalent mRNA boosters are recommended over the original (monovalent) boosters and is not currently authorized for use in a primary series.

Once eligible, the following groups may receive a booster dose based on the following:

• Infants and children 6 months to 4 years of age are not eligible at this time.
• For those 5 years and older, one booster dose (monovalent or bivalent) on or after September 1, 2022:
  • Children 5 to 11 years of age – the bivalent Pfizer-BioNTech (10mcg) vaccine is preferred.
  • Children 6 to 11 years of age may be given the bivalent Moderna (25 mcg) with informed consent, while supply is available.
  • Youth 12 to 17 years of age – the bivalent Pfizer-BioNTech (30mcg) vaccine is preferred. With informed consent, the bivalent Moderna (50 mcg) may be offered to those with weakened immune systems.
  • Adults 18-64 years of age may receive either mRNA bivalent booster dose (Pfizer-BioNTech or Moderna)

For people who are not able, due to contraindications, or willing to get a bivalent mRNA booster dose may consider getting one of the following, with informed consent:

• Ages 5+, the original (monovalent) mRNA
• Ages 18+, Novavax Nuvaxovid (0.5 mL) or the Janssen COVID-19 vaccines. Book an appointment.

Spring Booster eligibility:

As of April 3, 2023, the Ontario Ministry of Health recommends certain people who are at high-risk of severe illness and hospitalization receive a spring booster dose if it has been at least 6 months since their last COVID-19 dose or infection.

Eligible high-risk groups are:

• 65 years and older
• Residents of long-term care homes, retirement homes, elder care lodges, and other congregate living settings for seniors
• 18 years and older living in congregate care settings for people with complex medical care needs
• Pregnant individuals
• 18 years and older who are moderately to severely immunocompromised
• Indigenous people ages 55 years and over, and their non-Indigenous household members aged 55 years and over

For those outside of the high risk groups (listed above):

• There is currently no evidence that supports the need for an additional dose if a booster was already received on or after September 1, 2022
• To be considered up-to-date with COVID-19 vaccinations:
  • Everyone 5 years of age and older must complete a primary series and get a booster dose on or after September 1, 2022 if it has been at least 6 months after a COVID-19 vaccine dose or a COVID-19 infection
  • Children 6 months to under 5 years of age must complete a primary series

Book an appointment for a booster dose at our City-run clinics or pharmacies. Find out where to get vaccinated.

More Information:

• City of Toronto: COVID-19: Where to Get Vaccinated
• Ministry of Health: COVID-19 Vaccine Guidance

* Moderate to severely immunocompromised people, aged 6 months and over,  are eligible for an additional  dose to complete a primary series plus boosters (if 5 years of age and over)

Re-vaccination is recommended with a new COVID-19 vaccine primary series (3 doses) and booster given the loss of immunity following:

• hematopoietic stem cell transplant (HSCT)
• hematopoietic cell transplants (HCT) (autologous or allogeneic)
• CAR-T-cell therapy

Optimal timing should be determined on a case-by-case basis in consultation with your clinical team.

Please bring your referral form/letter to EACH of your vaccination appointments, highlighting this is to restart your primary series.

Everyone aged 6 months and older, without OHIP cards, may get vaccinated at any clinic or pharmacy clinic offering COVID-19 vaccines. Appointments for City immunization clinics must be made through the Provincial Vaccine Contact Centre at 1-833-943-3900.

Required Identification

For all clinics, bring an acceptable form of identification which may include non-Canadian and expired documents such as a driver’s licence or passport, a piece of mail with your name on it, a pay stub or a student card. Those 18 or older must provide photo ID.

Vaccines approved by Health Canada or are on the World Health Organizations (WHO) COVID-19 Vaccine Emergency Use Listing:

• If you completed a primary series and are 5 years of age and older, you may receive a bivalent booster dose at least 6 months since your last COVID-19 vaccine or infection
• If you did not complete the primary series of the non-Health Canada approved vaccine (e.g. only received 1 dose of a 2 dose series) and documented this dose, an additional Health Canada approved vaccine dose is required to complete your primary series

Vaccines approved for use in Canada are currently Comirnaty (Pfizer-BioNTech), SpikeVax (Moderna), Vaxzevria (AstraZeneca), Nuvaxovid (Novavax), and the single-dose Janssen (Johnson & Johnson).

Vaccines not authorized by Health Canada and are not on WHO’s COVID-19 Vaccine Emergency Use Listing:

• Document any dose(s) received and additional Health Canada approved doses will be required to complete the primary series
  • For people aged 5 years and over, one Health Canada approved dose is required
  • For people aged 5 years and over who are moderately to severely immunocompromised, two Health Canada approved doses are required

Unsure About Which Vaccine You Received

• If you received a previous dose and you do not have proof of vaccination, please contact the health care provider who gave you the COVID-19 vaccine(s) to receive a copy of your vaccination record.
• If the COVID-19 vaccine product used for your previous dose(s) remains unknown, or if written proof of vaccination is provided for a vaccine whose generic or trade name is not recognized, a new vaccine series should be started with a Health Canada authorized COVID-19 vaccine.
  • If you know the date of your previous COVID-19 immunization, wait at least 28 days before getting a new Health Canada authorized COVID-19 vaccine series.

If you are eligible for an additional dose(s), including a mRNA dose needed to complete your series or a booster dose, you can book an appointment at any City-run immunization clinic using your green photo Ontario Health Card (OHIP) number through the provincial portal or by calling 1-833-943-3900 (TTY 1-866-797-0007).

With an older red and white OHIP card number or with no OHIP number at all you can book an appointment by calling 1-833-943-3900 (TTY 1-866-797-0007). Walk-in appointments are also accepted. You do not need to wait until your out-of-province dose(s) is documented by Toronto Public Health.

Even with a previous COVID-19 infection, people who have not started/completed their primary series or those who are eligible for a booster dose, are still strongly recommended to complete their COVID-19 series. Immunity from an infection may not last and people can be infected with COVID-19 again.

Hybrid immunity means having protection from being vaccinated for COVID-19 and a recent past COVID-19 infection. A past COVID-19 infection can provide natural immunity, but it does not last long – especially with Omicron variants. You have a higher risk of getting COVID-19 again if you are not up-to-date with your vaccinations.

If you have had COVID-19 in the past you should still stay up to date with your vaccinations to get the benefit of hybrid immunity.

Every COVID-19 infection increases the risk for long COVID. To maximize the immune response after you have had COVID‑19, you should wait the following intervals after symptoms started or a positive test (if you had no symptoms) before receiving your next dose:

If completing your primary series:

• 2 months if you are not immunocompromised and have no history of multisystem inflammatory syndrome in children (MIS-C)
• 1 to 2 months (28 to 56 days) if you are immunocompromised but have no history of MIS-C
• if you have a history of MIS-C, until clinical recovery has been achieved or up to 90 days since the onset, whichever is longer, regardless of immunocompromised status

If getting a booster dose:

• 6 months after positive COVID-19 test or after having symptoms post contact with someone who had a positive test