Archive 40: Summary of updates in the Canadian Immunization Guide of August 29, 2022: Updated guidance on COVID-19 vaccines in Canada [2022-08-29]

Published: August 29, 2022

Overview

On August 29, 2022, the Public Health Agency of Canada (PHAC) released an updated COVID-19 vaccine chapter of the Canadian Immunization Guide (CIG) that included several recent updates from the National Advisory Committee on Immunization (NACI) on the use of COVID-19 vaccines. This guidance is based on current evidence and/or NACI's expert opinion.

What you need to know

The COVID-19 vaccine chapter was updated based on the following new guidance and/or information:

1. Information on a Health Canada authorized Pfizer-BioNTech Comirnaty booster dose to include individuals 16-17 years of age. Previously, a booster dose had been authorized by Health Canada only for individuals 18 years of age and older.
2. Guidance on COVID-19 vaccination among children 5 to 11 years of age with a history of myocarditis and/or pericarditis after a previous dose of mRNA COVID-19 vaccine.
3. Updated guidance on COVID-19 vaccination and tuberculin skin testing (TST) or interferon gamma release assay (IGRA).

Supporting information

1. Information on a Health Canada-authorized Pfizer-BioNTech Comirnaty booster dose in individuals 16 years of age or older

On June 1, 2022, Health Canada authorized the use of a booster dose of the Pfizer-BioNTech Comirnaty COVID-19 vaccine in adolescents 16 to 17 years of age. A single booster dose of the Comirnaty vaccine may be administered at least 6 months after completion of a primary series to individuals 16 years of age and older and is the same formulation and dosage strength (30 mcg/0.3 mL) as the booster dose authorized for use in individuals 18 years of age and older.

For additional information, refer to the Product Monograph:

• Pfizer Canada ULC. Product monograph – COMIRNATY™. June 1, 2022.

2. Guidance on COVID-19 vaccination among children 5 to 11 years of age with a history of myocarditis and/or pericarditis after a previous dose of mRNA COVID-19 vaccine

NACI was asked to issue guidance on COVID-19 vaccination among children 5 to 11 years of age with a history of myocarditis and/or pericarditis after a previous dose of mRNA COVID-19 vaccine. After reviewing the published literature and Canadian data, the NACI Vaccine Safety Working Group (VSWG) recommended extending existing guidance for individuals aged 12 years and older to include individuals 5 to 11 years of age. This decision was based on: vaccine principles, known safety profile of mRNA COVID-19 vaccines in all age groups (with increasing evidence of the safety of COVID-19 mRNA vaccines in children 5-11 years of age), and the need to provide the vaccine in situations where it may be particularly beneficial over any risk.

While no published studies assessing the risk of recurrence of myocarditis and/or pericarditis following receipt of further doses of COVID-19 vaccine have been identified, preliminary clinical experience from the Hospital for Sick Children’s Special Immunization Clinic (Toronto) showed that 7 youths (aged 12 to 17 years) with a history of chest pain after the first COVID-19 vaccine dose received a second vaccine dose and none had a recurrence of symptoms. Among these specific cases, the clinical presentation was similar to myocarditis and/or pericarditis. However, no cardiac investigations were performed at the time of symptom presentation, or the results of cardiac investigations were not consistent with a diagnosis of myocarditis and/or pericarditis and medical attention was not required. There is a need for studies on the safety of COVID-19 vaccination among individuals with a history of myocarditis and/or pericarditis after a previous dose of mRNA COVID-19 vaccine.

The following guidance was approved by NACI during a virtual meeting on July 5, 2022:

“As a precautionary measure until more information is available, further doses of mRNA COVID-19 vaccines should be deferred among individuals who have experienced myocarditis and/or pericarditis within 6 weeks following a previous dose of an mRNA COVID-19 vaccine in most circumstances. This includes any person who had an abnormal cardiac investigation including electrocardiogram (ECG), elevated troponins, echocardiogram or cardiac magnetic resonance imaging (MRI) after a dose of an mRNA COVID-19 vaccine.

Those with a history compatible with pericarditis and who either had no cardiac workup or had normal cardiac investigations can receive the next dose once they are symptom-free and at least 90 days have elapsed since vaccination.

Some individuals 5 years of age and older with confirmed myocarditis and/or pericarditis may choose to receive another dose of vaccine after discussing the risk and benefit with their healthcare provider. If another dose of vaccine is offered, they should be offered the Pfizer-BioNTech Comirnaty COVID-19 vaccine (at the age-appropriate dosage) due to the lower reported rate of myocarditis and/or pericarditis following the Pfizer-BioNTech Comirnaty (30 mcg) vaccine compared to the Moderna Spikevax (100 mcg) vaccine among individuals 12 years of age and older. Informed consent should include discussion about the unknown risk of recurrence of myocarditis and/or pericarditis following receipt of additional doses of Pfizer-BioNTech Comirnaty COVID-19 vaccine in individuals with a history of confirmed myocarditis and/or pericarditis after a previous dose of mRNA COVID-19 vaccine, as well as the need to seek immediate medical assessment and care should symptoms develop.”

Provided is the list of selected references that informed this guidance:

• Shimabukoro T. Update on myocarditis following mRNA COVID-19 vaccination. [Internet]. Atlanta (GA): Centers for Disease Control and Prevention (CDC); 2022 Jun 14 [cited 2022 Jul 21]. Available from: https://www.fda.gov/media/159228/download
• Hause AM, Baggs J, Marquez P, Myers TR, Gee J, Su JR, et al. COVID-19 Vaccine Safety in Children Aged 5-11 Years - United States, November 3-December 19, 2021. MMWR Morb Mortal Wkly Rep. 2021 Dec 31;70(5152):1755,1760. doi: 10.15585/mmwr.mm705152a1.
• Piche-Renaud P. Personnal Communication. SickKids Special Immunization Clinic: Experience with cases of myocarditis/pericarditis. 2022 Jun 1.
• Block JP, Boehmer TK, Forrest CB, Carton TW, Lee GM, Ajani UA, et al. Cardiac Complications After SARS-CoV-2 Infection and mRNA COVID-19 Vaccination - PCORnet, United States, January 2021-January 2022. MMWR Morb Mortal Wkly Rep. 2022 Apr 8;71(14):517,523. doi: 10.15585/mmwr.mm7114e1.
• Abraham N, Spruin S, Rossi T, Fireman B, Zafack J, Blaser C, et al. Myocarditis and/or pericarditis risk after mRNA COVID-19 vaccination: A Canadian head to head comparison of BNT162b2 and mRNA-1273 vaccines. Vaccine. 2022 Jul 30;40(32):4663,4671. doi: 10.1016/j.vaccine.2022.05.048.
• Buchan SA, Seo CY, Johnson C, Alley S, Kwong JC, Nasreen S, et al. Epidemiology of Myocarditis and Pericarditis Following mRNA Vaccination by Vaccine Product, Schedule, and Interdose Interval Among Adolescents and Adults in Ontario, Canada. JAMA Netw Open. 2022 Jun 1;5(6):e2218505. doi: 10.1001/jamanetworkopen.2022.18505.

3. Updated guidance on COVID-19 vaccination and tuberculin skin testing (TST) or interferon gamma release assay (IGRA)

This guidance was reviewed and revised following the release of updated recommendations from other jurisdictions around TST or IGRA theoretically affecting COVID-19 vaccination, and requests to clarify NACI’s existing guidance on this subject. After reviewing the published literature and evidence sought from manufacturers of COVID-19 vaccines, NACI approved changes to the guidance to indicate that vaccination with COVID-19 vaccines may take place at any time before, after or at the same visit as the TST or IGRA test. Subject matter experts with the Canadian Tuberculosis Standards group also provided feedback on the need for re-testing of individuals with negative TST or IGRA results for whom there is a high suspicion of tuberculosis infection.

The following guidance was approved by NACI during a virtual meeting on May 10, 2022:

“There is a theoretical risk that mRNA or viral vector vaccines could temporarily affect cell-mediated immunity, resulting in false-negative TST or IGRA test results. However, there is no direct evidence for this interaction. Therefore, in the absence of data and acknowledging the importance of both timely tuberculosis testing and immunization, vaccination with COVID-19 vaccines may take place at any time before, after or at the same visit as the TST or IGRA test. Repeat tuberculin skin testing or IGRA (at least 4 weeks post-COVID-19 immunization) of individuals with negative TST or IGRA results for whom there is high suspicion of latent tuberculosis infection may be considered in order to avoid missing persons with TB infection.”

Provided is a list of selected references that informed this guidance:

• COVID mRNA vaccines, TST, and IGRA – Follow-up. [Internet]. Atlanta (GA): Centers for Disease Control and Prevention (CDC); 2021 Aug 31 [cited 2022 Jul 21]. Available from: https://www.cdc.gov/tb/publications/letters/2021/covid-mrna-followUp.html
• Campbell JR, Pease C, Daley P, Pai M, Menzies D. Chapter 4: Diagnosis of tuberculosis infection. 2022 Mar 25;6:49,65. doi:10.1080/24745332.2022.2036503.
• Medicago. Personal Communication. 2022 Feb 23.
• Pfizer-BioNTech. Personal Communication. 2022 Mar 1.
• Moderna. Personal Communication. 2022 Mar 9.
• Janssen. Personal Communication. 2022 Mar 6.
• AstraZeneca. Personal Communication. 2022 Mar 10.
• Novavax. Personal Communication. 2022 Mar 10.
• Menzies R, Director, McGill International TB Centre. Personal Communication. 2022 July 19.

For more information regarding NACI’s recommendations on the use of COVID-19 vaccines, please refer to the COVID-19 vaccine chapter in the Canadian Immunization Guide (CIG), as well as additional statements on the NACI web page.