Questions about Third Doses

Why is a third dose of the COVID-19 vaccine needed?

Residents of long-term care and community care facilities, as well as individuals with a weakened immune system due to a medical condition may not have a strong enough response to the first doses of the COVID-19 vaccine to effectively protect them from becoming severely ill, being hospitalized or even dying from the virus.

The National Advisory Committee on Immunization (NACI) recently recommended an additional dose of the COVID-19 vaccine for those who are moderately or severely immunocompromised in order to provide them with additional protection against the virus.


Who should get a third dose of the COVID-19 vaccine?

Residents of long-term care and community care facilities are recommended for a third dose of the COVID-19 vaccine. Individuals with moderately to severely immunocompromised with the following conditions are also recommended for a third dose of the COVID-19 vaccine:

  • Active treatment for solid tumour or hematologic malignancies
  • Receipt of solid-organ transplant and taking immunosuppressive therapy
  • Receipt of chimeric antigen receptor (CAR)-T-cell therapy or hematopoietic stem cell transplant (within 2 years of transplantation or taking immunosuppression therapy)
  • Moderate to severe primary immunodeficiency (e.g., DiGeorge syndrome, Wiskott-Aldrich syndrome)
  • Stage 3 or advanced untreated HIV infection and those with acquired immunodeficiency syndrome
  • Active treatment with the following categories of immunosuppressive therapies: anti-B cell therapies (monoclonal antibodies targeting CD19, CD20 and CD22), high-dose systemic corticosteroids (e.g. 20 mg/day for ≥ 14 days), alkylating agents, antimetabolites, or tumor-necrosis factor (TNF) inhibitors and other biologic agents that are significantly immunosuppressive.

Where and when can I get a third dose of the COVID-19 vaccine?

Residents of long-term care facilities will receive their third dose at those facilities.

Individuals who meet the definition of moderately to severely immunocompromised can now receive the third dose of the vaccine at a COVID-19 Vaccine Clinic or from a participating pharmacy.

An individual should wait at least 28 days after receiving their second dose of the COVID-19 vaccine before receiving a third dose.


How do I know if I need a third dose of the COVID-19 vaccine?

If you are unsure about whether your health condition or treatment affects your immune system, you should speak with your health care provider(s) as they can help determine if you would benefit from a third dose of the vaccine.


Will individuals who are not immunocompromised need a third dose or booster of the COVID-19 vaccine?

The National Advisory Committee on Immunization is reviewing data to determine if a booster shot is needed for everyone.

Published date: 
October 19, 2021
Health and Wellness

General Inquiries

Department of Health and Wellness
4th Floor North, Shaw Building
105 Rochford Street
Charlottetown, PE   C1A 7N8

Phone: 902-368-6414
Fax: 902-368-4121

DeptHW@gov.pe.ca