COVID-19 Vaccine Second Dose Appointments

The Province of Ontario has announced the accelerated rollout of second doses for COVID-19 vaccines. A stable and reliable supply of COVID-19 vaccines has allowed the province to quickly expand eligibility and access to Ontarians to receive the vaccine ahead of schedule, providing a strong level of protection against the virus.

Please note: Individuals have the option to keep their original second dose appointment but are encouraged to get their second dose as soon as they are able. Appointments will not be automatically canceled or rebooked.


Please cancel your original appointment if you rebook an earlier appointment through a different channel/clinic.

  • If you had a second dose appointment through the Provincial Booking System, there is a link to cancel/reschedule in the appointment confirmation email that you received when you first booked or you can use the Manage your Appointment(s) page.
  • If you had a second dose appointment through the TBDHU COVID-19 Vaccine Appointment Booking System, there is a link to cancel in the appointment confirmation email that you received when you first booked or you can use the Cancel Appointment page.
  • If you had a second dose appointment at the TBRHSC Bora Laskin Clinic, you can cancel by giving your name, date of birth and second dose appointment by email to or by calling 935-8100 and pressing 3.
  • If you had a second dose at any other clinic/location, please contact them directly.


Groups Eligible for an Earlier Second Dose


  • Individuals aged 70 and older in 2021.
  • Individuals who received their first dose of an mRNA vaccine (Pfizer-BioNTech or Moderna) on or before April 18, 2021.
  • Individuals who received their first dose of the AstraZeneca vaccine should receive their second dose 8-12 weeks after their first appointment.


As of Monday, June 21, 2021 at 8:00 a.m., individuals who received their first dose of an mRNA vaccine (Pfizer-BioNTech or Moderna) on or before May 9, 2021 will be eligible to book or rebook their second dose appointment at a shortened interval.

Starting the week of June 28, 2021 (days/ sequence to be confirmed) all Ontarians aged 18 and over who have received their first dose of an mRNA COVID-19 vaccine will be eligible to book their second dose appointment. The appointment will be scheduled at least 28 days after the first dose, per the recommended interval.

Other Groups

There are some groups who remain at the dose interval outlined by the vaccine product monographs. See the list below of groups eligible for the original second dose interval

Youth will be eligible to receive a second dose 8 weeks (56 days) following their first dose. Those who booked through the provincial booking system will be able to schedule or re-book their second dose appointment through that system.


    Individuals who Received the Pfizer-BioNTech Vaccine for their First Dose


    Individuals who Received the Moderna Vaccine for their First Dose



    Individuals who Received the AstraZeneca Vaccine for their First Dose

    As of Saturday, June 12, 2021, Ontario accelerated the second dose interval for those who received a first dose of AstraZeneca to eight weeks with informed consent, from 12 weeks. See the media release for details.

    Individuals have the option of receiving a second dose of the AstraZeneca vaccine or choosing to have a second dose of one of the mRNA vaccines (Pfizer-BioNTech or Moderna). Review the Ministry of Health's COVID-19 Vaccine Information for Individuals who receive a first dose of AstraZeneca to help you to decide what choice is right for you. You can also have a discussion with a health care provider.

    Current evidence recommends waiting 12 weeks to receive a second dose as this interval allows for a better/optimal immune response to be achieved. However, the province recognizes that some may want to receive their second dose sooner to have the increased protection provided by an earlier second dose.

    For those who choose to receive a second dose of AstraZeneca, local supply will be available through participating pharmacies and one primary care office, the Fort William Family Health Team. Additional details regarding booking appointments will be shared on this page once the information is available.

    Those who choose to book an mRNA vaccine (Pfizer-BioNTech or Moderna) appointment should visit the COVID-19 Vaccine Appointment page to find a clinic.

    Additional information for those who choose an mRNA vaccine (Pfizer-BioNTech or Moderna) as their second dose:

    • The National Advisory Committee on Immunization (NACI) updated its guidance to recommended that a first dose of the AstraZeneca vaccine can be followed by an mRNA vaccine (Pfizer-BioNTech or Moderna).
    • The updated NACI guidance is based on emerging research from Spain and the United Kingdom that found mixing and matching the AstraZeneca and Pfizer-BioNTech vaccines was both safe and effective at preventing COVID-19.
    • Health Canada is monitoring the situation and reviewing new research from around the world as it becomes available.
    • Individuals with questions should speak to their health care provider about their own specific situation.
    • Individuals will be considered “fully immunized” if they choose an mRNA vaccine (Pfizer-BioNTech or Moderna) for their second dose.


    Don't know what vaccine you received?

    For those who are unsure what COVID-19 vaccine they received for their first dose, they should check their original appointment documentation or their printed/emailed receipt. Receipts can also be accessed through the Provincial Booking System.

    • Enter your postal code, date of birth and health card type. Click “Get results”.
    • On the next screen, select Option A - Provincial Booking System and click “Continue”.
    • If you read, understand and accept the terms of use, click “Continue”.
    • Complete the Identity Verification Information and click “Continue”.
    • Click “Continue” in the yellow box titled “Vaccination Receipts”.
    • You will now be able to review your results and access a PDF receipt.



    Groups Eligible for Original Second Dose Interval

    The dose interval will remain as per the product monograph for the following groups:

    • Those living in long-term care and retirement homes, Elder Care Lodges and Assisted Living facilities who are at the greatest risk of serious illness and death.
    • Those living in First Nation communities (including on reserve members and remote and isolated communities supported by Operation Remote Immunity).
    • Those who are transplant recipients, including solid organ transplants and hematopoietic stem cell transplants.
    • Those with malignant hematologic disorders and non-hematologic malignant solid tumours receiving active treatment, (chemotherapy, targeted therapies, immunotherapy), excluding individuals receiving solely hormonal therapy or radiation therapy. They should get the vaccine at a time when their immune system is best able to respond; this would happen in consultation with their health care provider. 
    • Those who are undergoing hemodialysis or peritoneal dialysis in the authorized age groups (eligible individuals under this category will be contacted by the TBRHSC directly).
    • Those who are urban Indigenous peoples and their family circle (eligible individuals should receive their second dose through the organization/clinic where they received their first dose. See the "Appointments for Indigenous Individuals" tab on the COVID-19 Vaccine Appointments page for links to urban Indigenous clinics in Thunder Bay).
    • Those who are high-risk health care workers. For a list of eligible workers, see the Ministry of Health backgrounder: High-Risk Health Care Workers Eligible to Receive a Second Dose of the COVID-19 Vaccine at a Shortened Interval. TBRHSC will contact eligible individuals to reschedule their second dose appointments.
    • Those in the authorized age groups who are taking an anti-CD20 agent (e.g. rituximab, ocrelizumab, ofatumumab). The timing of the vaccine should be decided with the treating provider in order to optimize the immune response from the vaccine series and minimize delays in management of their underlying condition.

    Individuals in the above groups can visit the TBRHSC COVID-19 Vaccinations page for information or email questions to

    Last Updated: 18/06/2021