COVID-19 Vaccine Update: Monovalent Pfizer-BioNTech Comirnaty for children aged 6 months to under 5 years available in Sudbury and Manitoulin districts

Advisory Alert

September 27, 2022

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To: Local Health System Partners


This Advisory Alert provides an overview of the Government of Ontario announcement and the updated Ministry COVID-19 Vaccine Administration (PDF) guidance pertaining to the monovalent Pfizer-BioNTech Comirnaty primary series for children aged 6 months to under 5 years. This is the second mRNA vaccine to be approved for use in this population and it is newly available in the Sudbury and Manitoulin districts.

Pfizer-BioNTech Comirnaty for children 6 months to less than 5 years

The Pfizer-BioNTech Comirnaty vaccine for children aged 6 months to less than 5 years is comprised of a 3-dose primary series. Each dose is 0.2mL and contains 3mcg of antigen. Eligible individuals are recommended to wait 56 days between doses; however, the first and second doses can be administered 21 days apart in with informed consent. Like other COVID-19 vaccines, individuals should be made aware that a longer interval between doses is associated with improved immune response.

Please note there is no preferential recommendation for either the monovalent Moderna Spikevax (25mcg) or the monovalent Pfizer-BioNTech Comirnaty (3mcg) vaccines in this age group. However, mixing products for a child’s primary series is not recommended and they should therefore receive the same product for all doses. This is particularly important for this population given the difference in the number of doses included in the primary series. At this time, children aged 6 months to less than 5 years old are not eligible for booster doses.

At this time, monovalent Moderna Spikevax (25 mcg) COVID-19 vaccine for ages 6 months to 5 years, as well as monovalent Pfizer-BioNTech Comirnaty (3 mcg) for ages 6 months to 4 years should not be given concurrently (i.e., same day) with non-COVID-19 vaccines but rather wait for a period of 14 days before or after administration of non-COVID-19 vaccines. This could prevent erroneous attribution of an adverse event to one of the vaccines.

Eligible and immunocompetent children with a history of COVID-19 infection are recommended to receive the vaccine 56 days after symptom onset or positive test. Immunocompromised children should wait 28 to 56 days from symptom onset or positive test, at the discretion of their clinician. When considering vaccine intervals, biological and social risk factors for exposure and severe disease should be examined. Before vaccination, individuals should no longer be considered infectious, and symptoms of acute illness should no longer be considered infectious.

Recommendations from the National Advisory Committee on Immunization (NACI) on the schedule for moderately to severely immunocompromised infants and children 6 months to 4 years of age who receive the Pfizer-BioNTech Comirnaty (3mcg) vaccine are pending. Stay tuned to future issues of the Advisory Alert as this will be communicated once available.

Vaccination against COVID-19 improves immune response to infection and reduces the possibility of severe disease and hospitalization. It continues to be one of our best defences against the virus. Individuals aged 6 months and older are strongly recommended to complete a primary series as soon as possible.

Primary care involvement

Primary care has multiple roles to play in the vaccine program, including onboarding practices to administer the vaccine in their offices, supporting vaccination clinics, and ongoing patient education on vaccine safety and efficacy.

Primary care providers interested in offering the COVID-19 vaccine through their practice are asked to contact Public Health at To request additional COVID-19 vaccines, please contact us at

Local vaccination opportunities

Visit our vaccination clinics for COVID-19 webpage for information on clinic dates, times, and locations. Eligible clients are encouraged to book an appointment online at or by calling 705.522.9200 (toll-free 1.866.522.9200) between 8:30 a.m. and 4:30 p.m., Monday to Friday. Clients can also contact a participating pharmacy, primary care provider, or health centre.


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 September 27, 2022