Additional Dose Information

Staying up to date with your COVID-19 vaccine

To stay up to date with your COVID-19 vaccinations, visit our webpage to learn of available Regional clinics, pharmacies and more.

Find out more about eligibility criteria in the drop-downs below.

If you have questions about your eligibility, please contact your primary health care provider or family doctor.

First and Second Dose

Six months and older

The Ministry of Health is recommending an interval of eight weeks between first and second doses. There is emerging evidence that longer intervals between the first and second doses of COVID-19 vaccines result in more robust and durable immune response and higher vaccine effectiveness.

If you received Moderna, Pfizer or AstraZeneca , or Novavax as your first dose, you may receive a second dose of Pfizer or Moderna eight weeks (56 days) after your first dose to complete the primary series, or as directed by your health-care provider.

Please note, in Ontario, the AstraZeneca vaccine is not available for first or second doses.

Those who do not wish to receive an mRNA COVID-19 vaccine series or booster can receive the Novavax COVID-19 vaccine via their Primary Care provider or local Pharmacy. The Novavax vaccine is a two-dose recombinant protein subunit vaccine authorized for adults 18 years of age and older. 

For some persons who are moderately to severely immunocompromised, the primary series is three doses to complete. See the below Immunocompromised specific drop-down menu for more information. 

Mixing vaccine types for the second dose

If you received an mRNA vaccine (Pfizer or Moderna) for your first dose, you can safely take either Moderna or Pfizer for your second dose for strong protection. Both Moderna and Pfizer vaccines are authorized for use in Canada and use a similar mRNA technology, so the vaccines are safe to mix. This is consistent with recommendations provided by the National Advisory Committee on Immunization and with practices within several provinces.

First Booster Dose (Third Dose)

Ages 5 – 11

  • Not currently eligible for a booster dose (third dose)

For children ages 5-11 who are moderate to severely immunocompromised, please see our immunocompromised specific drop-down menu for more information.

Ages 12 – 17

  • Recommended to receive a booster dose (third dose) at six months (168 days) after completion of their primary series 
  • For immunocompromised youth please see our Immunocompromised specific drop-down menu

First Nations, Inuit and Métis individuals, and Health care workers 16+ 

  • May receive a first booster dose (third dose) three months (84 days) after completion of their primary series 

Ages 18+ May receive a booster dose (third dose) at three months (84 days) after completion of their primary series. 

Mixing vaccine types for the third or booster dose

If you received an mRNA vaccine (Pfizer or Moderna) for your second dose, you can safely take either Moderna or Pfizer for your third dose for strong protection. Both Moderna and Pfizer vaccines are authorized for use in Canada and use a similar mRNA technology, so the vaccines are safe to mix. This is consistent with recommendations provided by the National Advisory Committee on Immunization and with practices within several provinces.

If you received AstraZeneca for your second dose, a booster dose of an mRNA vaccine (Pfizer or Moderna) is recommended.

Second Booster Dose (Fourth Dose)

Ages 5 – 17

  • Not currently eligible to receive a booster dose

Ages 18+ 

  • Currently eligible to receive a second booster dose (fourth dose)

For those who are moderate to severely immunocompromised, please see our immunocompromised specific drop-down menu below for more information.

Immunocompromised Three Dose Primary Series

A third dose may be administered as part of the primary series at a minimum of eight weeks (56 days) after the second dose for individuals 5 years of age or older with the following qualifying medical conditions:

  • Individuals receiving active treatment (e.g., chemotherapy, targeted therapies, immunotherapy) for a solid tumour or hematologic malignancies
  • Recipients of solid-organ transplant and taking immunosuppressive therapy
  • Recipients of chimeric antigen receptor (CAR)-T-cell therapy or hematopoietic stem cell transplant (within two years of transplantation or taking immunosuppression therapy)
  • Receiving dialysis (hemodialysis or peritoneal dialysis)
  • Individuals with moderate to severe primary immunodeficiency (e.g., DiGeorge syndrome, Wiskott-Aldrich syndrome)
  • Individuals with stage 3 or advanced untreated HIV infection and those with acquired immunodeficiency syndrome
  • Individuals receiving active treatment with the following categories of immunosuppressive therapies: anti-B cell therapies (monoclonal antibodies targeting CD19, CD20 and CD22), high-dose systemic corticosteroids, alkylating agents, antimetabolites, or tumour-necrosis factor (TNF) inhibitors and other biologic agents that are significantly immunosuppressive.

Eligible immunocompromised individuals aged:

  • 18 years and over should get a second booster (fifth dose) five months (140 days) after their first booster (or a minimum of three months or 84 days)
  • 12 to 17 years old should get a second booster (fifth dose) six months (168 days) after their first booster (or a minimum of three months or 84 days)

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