Archive 28: Summary of NACI advice on vaccination with COVID-19 vaccines following myocarditis (with or without pericarditis) [2022-01-14]

Publication date: January 14, 2022

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• Overview

Overview

• On January 14, 2022, the Public Health Agency of Canada (PHAC) released updated guidance from the National Advisory Committee on Immunization (NACI) in the COVID-19 vaccine chapter of the Canadian Immunization Guide, on the topic vaccination following myocarditis and pericarditis. This chapter includes NACI’s recommendations on the use of COVID-19 vaccines up to and including January 14, 2022.
• Rare cases of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the heart lining) following vaccination with COVID-19 mRNA vaccines have been reported in Canada and internationally. Most cases have occurred in males 12 to 29 years of age after a second dose of an mRNA vaccine. Most cases have been mild and resolved quickly.
• Following review of the latest evidence and consultation with Canadian cardiologists, NACI has issued updated guidance on re-vaccination with COVID-19 vaccines for those who experienced myocarditis and/or pericarditis after a previous dose of an mRNA COVID-19 vaccine.
• Since June 2021, NACI has recommended that people who experienced myocarditis and/or pericarditis after a first dose of an mRNA COVID-19 vaccine should wait to get their second dose until more information was available.

NACI continues to recommend that:

In most circumstances, and as a precautionary measure until more information is available, further doses of mRNA COVID-19 vaccines should be deferred among people who experienced myocarditis (with or without pericarditis) within 6 weeks of receiving a previous dose of an mRNA COVID-19 vaccine. This includes any person who had an abnormal cardiac investigation including electrocardiogram (ECG), elevated troponins, echocardiogram or cardiac MRI after a dose of an mRNA vaccine.

NACI now recommends that:

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 has passed since vaccination.

Some people with confirmed myocarditis (with or without pericarditis) after a dose of an mRNA COVID-19 vaccine may choose to receive another dose of vaccine after discussing the risks and benefits with their healthcare provider. If another dose of vaccine is offered, they should be offered the Pfizer-BioNTech 30 mcg vaccine due to the lower reported rate of myocarditis and/or pericarditis following the Pfizer-BioNTech 30 mcg vaccine compared to the Moderna 100 mcg vaccine. Informed consent should include discussion about the unknown risk of recurrence of myocarditis and/or pericarditis following receipt of additional doses of Pfizer-BioNTech 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.

• NACI will continue to review and monitor the evidence on vaccination following myocarditis and/or pericarditis after a dose of an mRNA COVID-19 vaccine as it emerges and will update their recommendations as needed.
• To read the full guidance, please refer to the new COVID-19 vaccine chapter in the Canadian Immunization Guide.
• If you would like to be notified about the release of new NACI guidance or updates to the CIG, please subscribe to the NACI & CIG publications mailing list.