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Niagara Health will administer third COVID-19 vaccine doses to select high-risk populations starting Aug. 31

Posted Aug 30th, 2021

Receiving a complete two-dose COVID-19 vaccine series provides strong protection against COVID-19 in the general population. However, for some more vulnerable populations, a third dose may be required. The Province of Ontario recently announced offering third doses of a COVID-19 vaccine to select high-risk populations:

  • Transplant recipients (including solid organ transplant and hematopoietic stem cell transplants)
  • Patients with hematological cancers (examples include lymphoma, myeloma, leukemia) on active treatment (chemotherapy, targeted therapies, immunotherapy) for malignant hematologic disorders
  • Recipients of an anti-CD20 agent (e.g. rituximab, ocrelizumab, ofatumumab)
  • Residents of high-risk congregate settings including long-term care homes, higher-risk licensed retirement homes and First Nations Elder Care Lodges

Niagara Health will administer third COVID-19 vaccine doses starting Tuesday, Aug. 31 at our St. Catharines Site as walk-in only between 8 a.m. and 3 p.m. (closed between 12 and 1 p.m.) on a first-come, first-served basis.

Eligibility letters are required for third doses and must include:

  • Dated and on letterhead
  • Contact information for physician, specialist or medical practice of individual completing the form
  • Patient’s name (typed/generic letters will not be accepted)
  • List of specific criteria required for patient eligibility
  • Patient’s eligible condition for third dose

Transplant recipients, patients with hematological cancers on active treatments and recipients of an anti-CD20 agent can receive their third dose at a minimum of eight weeks (56 days) following their second dose and will be contacted directly by their health care provider, such as their primary care provider, specialist or hospital specialty program.

Third doses will be offered to residents of long-term care homes and provincially-designated high-risk retirement homes at a minimum of five months following their second dose and will be co-ordinated through Public Health.

Eligible high-risk populations with eligibility letters can also receive their third dose at any Niagara Region Public Health vaccination clinics.

For more information, please visit

Niagara Health System