COVID-19 Vaccine Information: Second Dose

Who’s eligible to book an earlier second dose appointment:
Anyone who received their first dose of an mRNA vaccine on or before May 30, 2021, as well as individuals 70 and older (born in 1951 or earlier) are able to book at a shortened second dose interval. When booking, please be patient with staff during this busy time. See the full list below of who is eligible for a shortened second dose interval

If you choose to try to book an earlier appointment, please ensure you cancel your existing appointment in advance so that someone else has time to fill this spot. To cancel an appointment, use our online cancellation form

To find out the earliest date that you are eligible for your second dose appointment, use the the HPPH second dose calculator. 

Second Dose Calculator

How to book your second dose

  • Use the second dose calculator above to find out when you can receive your second dose.
  • If your earliest possible second dose date falls within the date range of an upcoming HPPH clinic, please book an appointment. If clinics are not yet available during the time you are due for your second dose, please check back for future clinics.
  • You can also subscribe to the COVID-19 Vaccine: Booking Appointments webpage to get alerts when new clinics are added using the "Subscribe to page updates" button on the bottom right-hand side of the page.
  • HPPH does not book second dose appointments when you get your first dose. You must book your second dose once you are eligible.

Mixing vaccines 

  • Canada’s National Advisory Committee on Immunization (NACI) has updated its recommendations on using a different COVID-19 vaccine for a second dose. This is called vaccine interchangeability or “vaccine mixing.”  Mixing vaccines is not a new concept. For example, similar vaccines from different manufacturers are sometimes used to complete a vaccine series for influenza, hepatitis A and other illnesses.
  • Know which vaccine to expect at HPPH clinics. All clinics on the COVID-19 Vaccine: Booking Appointments page show which vaccine is expected to be administered at that clinic. If you would like to receive a specific vaccine product, then book into an HPPH clinic that offers that product. Please note that due to supply changes, we cannot always guarantee the availability of a specific vaccine.  In that case, we will offer an appropriate alternative. You can then decide if you wish to proceed and receive the vaccine. 
  • Make your second dose a priority. Whether it’s the same vaccine series or a mix of two vaccines, being fully vaccinated is extremely valuable. Two doses of vaccine provide very good protection against COVID-19 and variants, including the Delta variant. As more and more community members become fully vaccinated, the more people are protected and the closer the pandemic is to ending. 
If you received Pfizer or Moderna for your first dose: 
  • You may receive either a Pfizer or Moderna vaccine as your second dose. 

  • Pfizer and Moderna are interchangeable COVID-19 mRNA vaccines.

    • The Public Health Agency of Canada and the Ontario Ministry of Health have endorsed the interchangeability of Pfizer and Moderna mRNA vaccines. This means that you can receive one of these vaccine products for your first dose and the other vaccine product for your second dose. You will still gain safe and highly effective protection against the COVID-19 virus, including the variants of concern, when mixing these products. Many of our neighbouring regions have moved to mix mRNA vaccines and we expect this to continue to be common practice moving forward.

    • “Mixing” vaccines is not a new concept. For example, similar vaccines from different manufacturers are sometimes used to complete a vaccine series for influenza, hepatitis A and other illnesses.

If you received AstraZeneca for your first dose: 
  • If you received the AstraZeneca COVID-19 vaccine as your first dose, you can choose to either receive a second dose of AstraZeneca or an mRNA vaccine (Pfizer or Moderna) at an 8 to 12-week interval. 
    • Both second dose options available to individuals who received their first dose of the AstraZeneca vaccine are safe and provide strong protection against COVID-19 and will count as a completed series. These second dose options will be provided at the recommended 8 to 12-week interval.
    • There is evidence that a longer interval between two doses (12-week interval) provides higher protection. However, some people may choose to receive their second dose sooner to have the increased protection provided by a second dose earlier.
    • Some people, in consultation with their health care provider, may need to book earlier than 8 weeks due to their medical treatment schedule.
  • Individuals who received their first dose of the AstraZeneca vaccine 8 to 12 weeks ago and who would like their second dose of the AstraZeneca vaccine can:
  • Opting for an mRNA vaccine (Pfizer or Moderna) as your second dose:
    • Individuals who received their first dose of the AstraZeneca vaccine and would like a second dose of mRNA vaccine (provided at the 8 to 12-week interval) can schedule their second dose appointment at a future HPPH clinic through the HPPH online or telephone booking system.
    • Individuals may also book their second dose appointment at a participating pharmacy where the Pfizer or Moderna vaccines are administered. Visit COVID-19 Pharmacy Vaccine Locations for a list of local participating pharmacies. 

AstraZeneca Second Dose Decision Chart

COVID-19 Vaccine Information for Individuals who received a first dose of the AstraZeneca COVID-19 vaccine/COVISHIELD vaccine | Ministry of Health

Shortened second dose interval (original dose schedule)

List of who is eligible for a shortened second dose interval

Following the most current Ministry direction, the following groups are eligible to receive an earlier second dose appointment:

  • Individuals 70 and older (born in 1951 or earlier)
  • Anyone who received their first dose of vaccine on or before May 30, 2021
  • Indigenous adults 16 years of age and older, and household members who are not Indigenous
  • Eligible high-risk health care workers
  • Essential Caregivers of long-term care and retirement homes
    • Please note: this does not include “primary essential caregivers” attached to other eligibilities (e.g. health conditions). Primary essential caregivers will receive their second dose of vaccine at the extended dose interval of 16 weeks.

Certain medical conditions are not only eligible for the shortened interval, but should be done as close as possible to the interval on the product monograph. If you are eligible due to one of the following conditions, we will try to book you as close to the product monograph as possible. Please call us if an appointment time within 28 days (of your first dose) is not available, and speak to your healthcare provider first to determine the best timing for your vaccine given your treatment plan. 

  • Individuals on immunosuppressive therapy who are taking an anti-CD20 agent (e.g., rituximab, ocrelizumab, ofatumumab)
  • Transplant recipients (including solid organ transplants and hematopoietic stem cell transplants)
  • Malignant hemotologic disorders on immunocompromising therapy (chemotherapy, targeted therapies, immunotherapy)
  • Nonhemotologic malignant solid tumors on immunocompromising therapy (chemotherapy, targeted therapies, immunotherapy); excludes individuals receiving solely hormonal therapy or radiation therapy
  • Individuals undergoing hemodialysis or peritoneal dialysis
  • Individuals with an imminent start date for any of the above treatments or therapies

Extended interval (16 week schedule)

Anyone not eligible for the shortened second dose interval can receive their second dose at the extended interval (aiming for 16 weeks).

  • The HPPH second dose calculator will calculate your earliest second dose date based on your eligibility.
  • If you book an appointment before your earliest possible appointment date, and you do not qualify for the earlier dose schedule, you will be turned away at the clinic.
  • If you can't book a clinic spot at 16 weeks, please book an appointment for the closest time that is available.