COVID-19 vaccine update: verifying immunosuppressive prescriptions for third doses, and expanded eligibility criteria for vulnerable elderly living in congregate settings

Advisory Alert

October 8, 2021

*Cette information est seulement disponible en anglais.

To: Local Health System Partners

Guidance on third doses for those on immunosuppressive medication and new eligibility for third doses among vulnerable elderly in congregate settings

This Advisory Alert outlines a new process to verify eligible immunosuppressive prescriptions and third dose implementation for individuals on certain immunosuppressive agents. This Advisory Alert also provides an update on the expanded third dose eligibility for vulnerable elderly in congregate settings including retirement homes and other congregate care. This information is subsequent to previous Advisory Alerts dated September 16, 2021 and August 31, 2021 which discussed third dose rollout for select vulnerable populations and third dose recommendations for vulnerable groups, respectively.

Clinic guide to verifying immunosuppressive prescriptions for third doses of COVID-19 vaccine

Please read the clinic guide (PDF) which provides guidance for validating client’s eligibility based on their medication prescriptions. Once prescription details and drug name are verified, the health care practitioner can proceed to administer the COVID-19 vaccine and document immunization in COVax or refer the client to a site who is administering the vaccine.

Proposed implementation options and process

The Ministry of Health has outlined implementation options and processes for administering third doses of a COVID-19 vaccine among those who are moderately to severely immunosuppressed.

Clients eligible for a third dose of the COVID-19 vaccine due to immune compromise may receive vaccine from their treating provider or be referred to a Public Health Sudbury & Districts COVID-19 vaccine clinic or participating pharmacy.

To ensure that vaccines are timed appropriately and third doses are provided only to eligible individuals, physicians are to complete the referral form English (PDF), French (PDF). Eligible clients will bring the completed referral form with them to a COVID-19 vaccine clinic.

Clients who are taking an immunosuppressive medication that makes them eligible for a third dose due to moderate or severe immune compromise may also present to a Public Health Sudbury & Districts COVID-19 vaccine clinic or pharmacy with proof of prescription vial, receipt, or prescription confirmation. For a list of eligible medications, please see the Clinic Guide to Verifying Immunosuppressive Prescriptions for Third Doses of the COVID-19 Vaccine (PDF).

More information on COVID-19 vaccine third dose recommendations (PDF) is available from the Ministry of Health.

Expanded dose three eligibility for seniors living in congregate settings

Residents of retirement homes and elderly living in other congregate settings (for example, assisted-living facilities, chronic care hospitals, naturally occurring congregate retirement settings, and congregate senior’s apartment buildings) are now eligible for a third dose of the COVID-19 vaccine.

Vulnerable elderly residing in retirement homes and other eligible congregate settings can receive a third dose of the COVID-19 vaccine at a minimum of five months (20 weeks) following their second dose. If available, residents are to receive the same vaccine product as their second dose.

Planning is currently underway with retirement home and congregate living partners for third dose rollout. Public Health Sudbury & Districts will contact all eligible settings directly to schedule the residents’ third dose. Residents will be notified when they are eligible for a third dose. Planning is underway to vaccinate eligible residents in their setting, not at a mass immunization clinic. Health care partners may support identification of eligible individuals and discuss third dose information with their patients.

To protect the elderly in congregate care settings, it is strongly recommended that all people that come into close contact with them (for example, health care workers and other support staff, family, friends, caregivers) complete a full two-dose vaccine series (i.e. “ring vaccination”) and also continue to follow recommended public health measures for prevention and control of COVID-19.

Vaccination options

Please visit our Vaccination clinics for COVID-19 webpage for information on clinic dates, times, and locations. Clients can also book an appointment online at or by calling 705.674.2299 (toll-free: 1.800.708.2505), between 8 a.m. and 6 p.m., Monday to Friday. Clients can also contact a local participating pharmacy.

Additional information

For more information on the COVID-19 vaccines, as well as for specific answers to your frequently asked questions visit our FAQ web page or call Public Health Sudbury & Districts at 705.522.9200 (toll-free 1.866.522.9200).


Original Signed By

Dr. Marlene Spruyt Acting Medical Officer of Health

This item was last modified on October 8, 2021