COVID-19 vaccine update: third dose rollout for select vulnerable populations

Advisory Alert

August 31, 2021

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To: Local Health System Partners


Third dose recommended for select vulnerable populations

This Advisory Alert provides an overview of third dose rollout for the COVID-19 vaccine considering your role as health care partners and addresses third dose rollout for vulnerable elderly in high-risk congregate settings. Third dose eligibility was previously outlined in an Advisory Alert dated August 18, 2021.

Supporting third dose rollout in your practice

A third dose of the COVID-19 vaccine is now recommended for select vulnerable populations to help provide an improved immune response and an added layer of protection against the Delta variant. An updated consent will be needed prior to third dose administration. If available, third doses should be the same product as second doses, but the mRNA vaccines can be safely interchanged if needed.

Those who are severely immunocompromised can receive their third dose at a minimum of eight weeks following their second dose. These individuals include:

Your assistance is requested for third dose rollout for severely immunocompromised

Acute care partners including hospital specialists, who may work at Health Sciences North and North East Cancer Centre, are asked to support the identification of severely immunocompromised individuals eligible for a third dose. Please reach out to your patients directly and provide all options and opportunities for third dose vaccination, including at some local pharmacies, doctor’s offices, and Public Health led clinics. A referral form will be required to receive a third dose, unless vaccination occurs on site with the Physician or Specialty Program responsible for patient care.

Primary care providers and pharmacists are asked to identify those patients not identifiable by the hospital or acute care specialists. Primary care providers and pharmacies who have been onboarded to administer the COVID-19 vaccine can provide third doses to those eligible patients. Alternatively, please complete the required referral form and direct patients to community vaccination opportunities for a third dose.

To ensure no eligible individuals are missed in the process, Public Health Sudbury & Districts will issue public communication regarding the eligibility criteria for third doses in about 1-2 weeks. Eligible individuals will be asked to seek an assessment from their health care provider to confirm eligibility and obtain the referral form for third dose vaccination. These individuals may then receive the vaccine with their primary care provider, pharmacy, or Public Health led community clinic. Please note, the referral form is required under all circumstances, unless the vaccine is administered on site by the Physician or Specialty Program responsible for patient care.

If you are interested in onboarding to the primary care vaccine program, please contact us at Primary care has multiple roles to play in the vaccine program including onboarding practices to administer the vaccine in their offices, supporting mass vaccination clinics, mobile units and, ongoing patient education on vaccine safety and efficacy.

Third dose rollout in high-risk congregate settings

Vulnerable elderly residing in high-risk congregate settings can receive a third dose of the COVID-19 vaccine at a minimum of five months following their second dose. These individuals include:

Planning is currently underway with our long-term care home and elder care lodge partners for third dose rollout. Public Health Sudbury & Districts’ does not have high-risk retirement homes in the service area. Residents will receive their third dose in their residence, either by the home’s staff or through a mobile clinic offered by Public Health Sudbury & Districts. Residents will be notified when they are eligible for a third dose. Health care partners may also help support or notify long-term care home and elder care lodge residents.

Patients designated Alternate Level of Care (ALC) who are waiting to be transferred to long-term care homes are eligible for a third dose and can receive their dose from the hospital or Public Health Sudbury & District mobile team. Also, patients designated ALC who are awaiting transfer to a long-term care home from a licensed retirement home are also eligible for a third dose. In addition, seniors living in assisted living facilities co-located with a long-term care home are eligible for a third dose.

Vaccination opportunities

Current vaccination options include pop-up clinics and mobile clinics at various locations throughout our communities, in addition to mass immunization clinics and some pharmacy and primary care locations. Vaccination to client is also a possibility for those who are homebound.

Anyone can 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 5:30 p.m., Monday to Friday. Individuals or organizations can also request pop-up or mobile bus vaccination opportunities at their event or place of work by contacting All requests will be assessed for feasibility.

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).

As Ontario enters the fourth wave, we strongly recommend that employers put vaccination policies in place to protect their employees and the public from COVID-19. Thank you for your support with the COVID-19 vaccine program. We value and appreciate your collaboration to ensure efficient COVID-19 vaccine rollout within our communities.



Original Signed By

Dr. Penny Sutcliffe
Medical Officer of Health and Chief Executive Officer

NOTE: All Advisory Alerts are found on our website.

This item was last modified on August 31, 2021