Exceptions to Extended Dose Intervals for COVID-19 vaccines

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Vaccine Clinical Advisory Group (VCAG) Recommendations on Exceptions to Extended Dose Intervals for COVID-19 vaccines (March 26, 2021) and Highest Risk Populations – Phase 2

The province has now entered Phase 2 of the vaccine roll-out plan, focused on age and at-risk populations.

As of April 16, 2021 at 8 a.m. people with the highest-risk health conditions can call the provincial call centre at 1-833-943-3900 to book an appointment for first and second dose. They will be asked to identify and confirm themselves as having a highest risk health condition.

Eligible Highest-risk health conditions

  • Organ transplant recipients (including patients waitlisted for transplant)
  • Hematopoietic stem cell transplant recipients
  • Neurological diseases in which respiratory function may be compromised (e.g., motor neuron disease, myasthenia gravis, multiple sclerosis)
  • Haematological malignancy diagnosed <1 year
  • Kidney disease eGFR< 30  
  • Pregnant women 

These patients are also eligible to have one (1) essential caregiver vaccinated at the time they receive their first dose. Caregivers’ first appointment should be booked at the same time as the eligible highest risk individual. Essential caregivers will not be eligible for the shortened second dose interval.

Special Considerations on Second Dose Intervals

Only the following Highest Risk populations are eligible to receive the COVID-19 vaccine at the shortened dose interval of 26 days (for both Moderna and Pfizer-BioNTech COVID-19 Vaccines) or 12 weeks for AstraZeneca.

  • Transplant recipients (including solid organ transplants and hematopoietic stem cell transplants)
  • Individuals with malignant hematologic disorders and non-hematologic malignant solid tumors receiving active treatment (chemotherapy, targeted therapies, immunotherapy) excluding individuals receiving solely hormonal therapy or radiation therapy

Essential caregivers will not be eligible for the shortened second dose interval. The duration between doses will be 16 weeks (4 months).

This patient group will require a letter or form from their clinician to confirm that they are eligible to receive a second dose appointment at the 26-day interval, identifying the reason for exception. The letter or form should be presented at both the first and second appointments to confirm that they are eligible to get a second dose appointment at the shortened dose interval.

If you have already received a first dose of COVID-19 vaccine, then you must provide your clinician with the proof of vaccination slip. Individuals will need to receive the second dose of the same COVID-19 vaccine received at first dose.

Health conditions not yet included in prioritization of COVID-19 vaccination

At-risk health conditions:

  • Immune deficiencies/autoimmune disorders
  • Stroke/cerebrovascular disease
  • Dementia
  • Diabetes
  • Liver disease
  • All other cancers
  • Respiratory diseases
  • Spleen problems (e.g., asplenia)
  • Heart disease
  • Hypertension with end organ damage
  • Diagnosis of mental disorder
  • Substance use disorders
  • Sickle Cell Disease
  • Thalassemia
  • Immunocompromising health conditions
  • Other disabilities requiring direct support care in the community

Patients who have scheduled 1st vaccination in Ministry Vaccination Tool who are required to change 2nd dose to 26 day interval

Please follow these instructions

If the patient has already received a first dose of COVID-19 vaccine, the patient must provide their clinician with their proof of vaccination slip to complete this form. This form (or similar letter from the clinician) must be presented at their second dose appointment to confirm eligibility for second dose at the 26-day interval. Patients must contact the hospital, pharmacy, or Public Health Unit where they received their first dose to arrange their second dose at the shorter interval and will need to receive the same COVID-19 vaccine received at first dose.

  • Niagara Health (905-378-4647, Ext. 49099) for vaccination at Seymour-Hannah Sports and Entertainment Centre
  • Niagara Region Public Health (905-688-8248, press 7 then press 2) for all Public Health clinic locations


Niagara Health System