Question Period Note: NACI recommendations on the use of COVID-19 vaccines

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• NACI may make recommendations that are broader or narrower than the conditions of use approved by Health Canada (known as ‘off-label’ recommendations). As the regulator, Health Canada rigorously evaluates safety and efficacy data from clinical trials before authorizing vaccines but does not dictate practice of medicine or make recommendations on how the vaccines should be used for public health impact.
• Canada’s National Advisory Committee on Immunization (NACI) updates its recommendations on COVID-19 vaccines based on the latest scientific evidence and its expert opinion.
• COVID-19 vaccines authorized for use in Canada have been essential in saving lives and protecting the health of Canadians, and reducing the burden on the health care system.
• At this point in the pandemic, it is important for individuals to receive a booster dose when recommended to continue to protect themselves against severe outcomes from COVID-19.
• In addition to keeping up to date with vaccination, wearing a well-fitting mask, hand hygiene and physical distancing, continue to be strategies individuals can employ to help lower their individual risk of contracting COVID-19.

If pressed on guidance on fall booster doses
• NACI strongly recommends that all individuals 65 years of age and older and individuals 12 years of age and older who are at increased risk of severe illness from COVID-19 should be offered a fall COVID-19 vaccine booster dose, regardless of the number of booster doses previously received.
• NACI recommends that all other individuals 12 to 64 years of age may be offered a COVID-19 booster dose, regardless of the number of booster doses previously received.
• NACI recommends that bivalent Omicron-containing mRNA COVID-19 vaccines are the preferred products for fall booster doses.
• NACI recommends that COVID-19 fall booster doses may be offered at an interval of 6 months since the previous COVID-19 vaccine dose or infection. A shorter interval of at least 3 months may be considered, particularly in the context of heightened epidemiological risk, evolving epidemiology and operational considerations for the efficient deployment of fall immunization programs. Based on what is known at this time about the virus and vaccines, it is not expected that a booster dose will be routinely provided every 3 months.
• There may be variability in how each province, territory or community assesses risk and responds to the needs of their respective jurisdictions

If pressed on primary series for children 6 months to 5 years of age
• Most children who get COVID-19 have mild or no symptoms; however, some children, including previously healthy children, experience severe disease and require hospitalization. Children who have an underlying medical condition may be at higher risk of severe outcomes from COVID-19.
• NACI recommends a 2-dose primary series of the Moderna Spikevax COVID-19 vaccine (25 mcg) may be offered to children 6 months to 5 years of age.
• NACI recommends that children 6 months to 5 years of age who are moderately to severely immunocompromised may receive a 3-dose primary series.
• It is essential that children and their caregivers are supported and respected during the decision-making process so they are able to make an informed decision about COVID-19 vaccination.

If pressed on boosters for children 5 to 11 years of age
• NACI recommends a booster dose of the Pfizer-BioNTech Comirnaty (10 mcg) COVID-19 vaccine should be offered at least 6 months after the completion of a primary series to children 5 to 11 years of age who have an underlying medical condition, including children who are moderately to severely immunocompromised, that places them at high-risk for severe COVID-19 outcomes.
• For all other children 5 to 11 years of age, NACI recommends that a booster dose of the Pfizer-BioNTech Comirnaty COVID-19 vaccine (10 mcg) may be offered at least 6 months after the completion of a primary series based on heightened epidemiological risk.
• It is essential that children and their caregivers are supported and respected during the decision-making process so they are able to make an informed decision about COVID-19 vaccination.

NACI guidance is based on current evidence and expert opinion. NACI continues to closely monitor the evolving evidence on COVID-19 and COVID-19 vaccines, including safety and effectiveness, and updates recommendations as needed.

Strong versus discretionary NACI recommendations
NACI makes two types of recommendations—strong recommendations and discretionary recommendations. A strong recommendation uses the words “should / should not be offered” and applies to most individuals in a population unless a compelling alternative is available. A discretionary recommendation uses the words “may / may not be offered” and means that the vaccine may be considered for individuals in a population, but that the decision should be made considering factors, such as individual benefits and risks, or local epidemiology.

COVID-19 vaccination for children
Most children who get COVID-19 have mild or no symptoms; however, some children, including previously healthy children, experience severe disease and require hospitalization. Children who have an underlying medical condition may be at higher risk of severe outcomes from COVID-19.

Primary series for children 6 months to 5 years of age
Two vaccines are approved for use in this population: the Moderna Spikevax mRNA (25 mcg) vaccine is authorized for children 6 months to 5 years and the Pfizer-BioNTech Comirnaty mRNA (3 mcg) vaccine is authorized for children 6 months to 4 years. For this population, NACI has only released guidance on the use of the Moderna Spikevax vaccine. Guidance on the use of the Pfizer-BioNTech Comirnaty vaccine is anticipated in October 2022.

NACI recommends that a 2-dose primary series with the Moderna Spikevax (25 mcg)vaccine may be offered to children 6 months to 5 years of age who do not have contraindications to the vaccine, with a dosing interval of at least 8 weeks between the first and second dose (Discretionary NACI Recommendation).

NACI recommends that children 6 months to 5 years of age who are moderately to severely immunocompromised may be offered a 3-dose primary series of the Moderna Spikevax (25 mcg) vaccine, using an interval of 4 to 8 weeks between each dose (Discretionary NACI Recommendation).

NACI currently recommends that COVID-19 vaccines should not routinely be given concurrently (i.e., same day) with other vaccines (live or non-live) for this age group (Strong NACI recommendation). This is a precaution to help determine if a side effect is due to the COVID-19 vaccine or another vaccine. There may be circumstances when a dose of a COVID-19 vaccine and another vaccine need to be given at the same time – a healthcare provider can help with this decision.

Primary series for children 6 to 11 years of age
Two COVID-19 vaccines are approved for use as a primary series in this population: the Pfizer-BioNTech Comirnaty mRNA (10 mcg) vaccine is authorized for children 5 to 11 years of age and the Moderna Spikevax mRNA (50 mcg) vaccine is authorized for children 6 to 11 years of age.

NACI recommends that a 2-dose primary series of an mRNA COVID-19 vaccine should be offered to children in the authorized age groups without contraindications to the vaccine, with a dosing interval of at least 8 weeks between the first and second dose (Strong NACI recommendation).

For children 6 to 11 years of age, the Pfizer-BioNTech Comirnaty (10 mcg) vaccine is preferred to the Moderna Spikevax (50 mcg) vaccine to start or continue the primary vaccine series. This is due to the well-known safety profile of the Pfizer-BioNTech Comirnaty (10 mcg) vaccine in this age group. The Moderna Spikevax vaccine may be offered as an alternative.

NACI recommends that children 5 to 11 years of age who are moderately to severely immunocompromised should be offered a 3-dose primary series of an mRNA COVID-19 vaccine with an interval of 4 to 8 weeks between each dose (Strong NACI recommendation).

Primary series for adolescents 12 to 17 years of age
Two COVID-19 vaccines are approved for use as a primary series in this population: the Pfizer-BioNTech Comirnaty mRNA (30 mcg) vaccine and the Moderna Spikevax mRNA (50 mcg) vaccine.

NACI recommends a complete primary series of an mRNA COVID-19 vaccine should be offered to adolescents 12 to 17 years of age who do not have contraindications to the vaccine with a dosing interval of 8 weeks between the first and second dose (Strong NACI Recommendation).

The Pfizer-BioNTech Comirnaty (30 mcg) vaccine is preferred to start or continue a primary series.

NACI recommends adolescents 12 to 17 years of age who are moderately to severely immunocompromised should be offered a 3-dose primary series of an mRNA COVID-19 vaccine. (Strong NACI recommendation)

Primary series for adults 18 years of age and over
Six COVID-19 vaccines are authorized for use in this population: Pfizer-BioNTech Comirnaty mRNA (30 mcg), Moderna Spikevax mRNA (100 mcg), Medicago Covifenz (18 to 64 years), Novavax Nuvaxovid, AstraZeneca Vaxzevria and Janssen Jcovden.

NACI recommends that a complete primary series with an mRNA COVID-19 vaccine should be offered to individuals in the authorized age group without contraindications to the vaccine, with a dosing interval of 8 weeks between the first and second dose (Strong NACI Recommendation).

NACI recommends that adults who are moderately to severely immunocompromised should be offered a 3-dose primary series of an authorized mRNA COVID-19 vaccine with an interval of 4 to 8 weeks between each dose (Strong NACI Recommendation).

For individuals 18 to 29 years of age, the Pfizer-BioNTech Comirnaty (30 mcg) vaccine is preferred to start or continue the primary series due to a lower reported rate of myocarditis/pericarditis compared to the Moderna Spikevax (100 mcg) vaccine.

NACI recommends a primary series of a protein subunit COVID-19 vaccine (Novavax Nuvaxovid) or a virus-like particle COVID-19 vaccine (Medicago Covifenz) may be offered to individuals in the authorized age groups without contraindications to the vaccine who are unable or unwilling to receive an mRNA COVID-19 vaccine (Discretionary NACI Recommendation).

NACI recommends that a primary series of a viral vector COVID-19 vaccine (AstraZeneca Vaxzevria, Janssen Jcovden) may be offered to individuals in the authorized age groups without contraindications to the vaccine only when all other authorized COVID-19 vaccines are contraindicated (Discretionary NACI Recommendation).

Booster dose for children 5 to 11 years of age
A booster dose can enhance protection from a primary series that may have decreased over time. The Pfizer-BioNTech Comirnaty mRNA (10 mcg) vaccine is authorized for use as a booster dose in children 5 to 11 years of age.

NACI recommends that children 5 to 11 years of age who have an underlying medical condition that places them at high-risk of severe illness due to COVID-19, including children who are immunocompromised, should be offered a booster dose of the Pfizer-BioNTech Comirnaty (10 mcg) vaccine at least 6 months after completion of a primary series (Strong NACI recommendation).

For all other children 5 to 11 years of age, NACI recommends that a booster dose of the Pfizer-BioNTech Comirnaty (10 mcg) vaccine may be offered at least 6 months after completion of a primary series, in the context of heightened epidemiological risk (Discretionary NACI recommendation).

Fall booster doses for adolescents and adults 12 years of age and over
NACI recommends that all individuals 65 years of age and older and individuals 12 years of age and older who are at increased risk of severe illness from COVID-19 should be offered a fall COVID-19 vaccine booster dose, regardless of the number of booster doses previously received (Strong NACI Recommendation).

NACI recommends all other individuals 12 to 64 years of age may be offered a fall COVID-19 booster dose, regardless of the number of booster doses they have previously received (Discretionary NACI Recommendation).

NACI recommends bivalent Omicron-containing mRNA COVID-19 vaccines are preferred for fall booster doses (Strong NACI Recommendation). Two bivalent Omicron-containing mRNA vaccines are authorized for use as a booster dose in Canada: the Pfizer-BioNTech Comirnaty BA.4/5 (30 mcg) vaccine is authorized for individuals 12+ and the Moderna Spikevax BA.1 (50 mcg) vaccine is authorized for individuals 18+.

Individuals 12 years of age and older who are not able or willing to receive a bivalent vaccine may be offered an original mRNA vaccine. Booster doses of original mRNA COVID-19 vaccines continue to provide good protection against severe outcomes from COVID-19, including from Omicron infection. People who have already received an original mRNA COVID-19 vaccine as a fall booster will have good protection against serious illness and hospitalization and do not need to be revaccinated with a bivalent Omicron-containing vaccine.

NACI strongly recommends that individuals who are pregnant should be offered a fall booster dose at any stage of pregnancy, regardless of the number of previously received booster doses. (Strong NACI Recommendation)

NACI continues to recommend that fall COVID-19 booster doses may be offered at an interval of 6 months after a previous COVID-19 vaccine dose or 6 months after SARS-CoV-2 infection. A shorter interval of at least 3 months may be considered, particularly in the context of heightened epidemiologic risk, evolving epidemiology and operational considerations for the efficient deployment of fall immunization programs. Based on what is known at this time about the virus and vaccines, it is not expected that a booster dose will be routinely provided every 3 months.

Recommendations related to myocarditis and/or pericarditis
Rare cases of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the heart lining) have been reported following vaccination with mRNA COVID-19 vaccines. Cases have occurred more frequently in males 12 to 29 years of age after a second dose of an mRNA COVID-19 vaccine. Most cases have been mild and resolved quickly. Based on data from the United States, the risk of myocarditis/pericarditis may be much lower in children 5 to 11 years of age than adolescents 12 to 17 years of age.

In order to further minimize the rare risk of adolescents and young adults experiencing myocarditis and/or pericarditis, the Pfizer-BioNTech Comirnaty COVID-19 (30 mcg) vaccine is preferred for use in adolescents and young adults 12 to 29 years of age for the primary series, as Canadian and international data suggest a lower reported rate of myocarditis following vaccination with the Pfizer-BioNTech Comirnaty (30 mcg) vaccine compared to the Moderna Spikevax (100 mcg) COVID-19 vaccine. The Pfizer-BioNTech Comirnaty (10 mcg) vaccine is also preferred to start or continue the primary vaccines series in children 5 to 11 years of age.

Based on clinical judgement, the Moderna Spikevax (100 mcg) vaccine may be considered for adolescents and adults 12 to 29 years of age who are moderately to severely immunocompromised given evidence that this vaccine may have a slightly higher vaccine effectiveness and may provide longer protection against infection and severe COVID-19 outcomes compared to the Pfizer-BioNTech Comirnaty (30 mcg) vaccine.

Out of precaution, 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. Some people who experienced myocarditis with or without pericarditis after a first 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 Comirnaty (30 mcg) vaccine due to the lower reported rate of myocarditis and/or pericarditis following this vaccine compared to the Moderna Spikevax (100 mcg) vaccine.

Individuals who have a history of myocarditis unrelated to mRNA COVID-19 vaccination should consult their clinical team for individual considerations and recommendations. People previously diagnosed with myocarditis but who are no longer being followed by a medical professional for heart issues should receive the vaccine.

COVID-19 vaccination following SARS-COV-2 infection
NACI continues to recommend COVID-19 vaccination for individuals who have had COVID-19. While infection alone provides some protection, hybrid immunity (i.e. conferred by vaccination and infection) provides better and longer lasting protection. Suggested intervals may change as evidence evolves.

At this time, NACI suggests that individuals 5 years of age and over who experience SARS-CoV-2 infection before starting or completing their primary COVID-19 vaccine series receive their next dose 8 weeks after symptoms started or after testing positive (if no symptoms were experienced).

For individuals 5 years of age and over who are recommended to receive a booster dose, the booster dose may be offered at an interval of 6 months after SARS-CoV-2 infection (or 6 months from a previous COVID-19 vaccine dose). A shorter interval of at least 3 months may be considered particularly in the context of heightened epidemiologic risk, evolving epidemiology and operational considerations for the efficient deployment of vaccine programs.

• The National Advisory Committee on Immunization (NACI) is an external body of experts that provides recommendations to the Public Health Agency of Canada on the use of authorized COVID-19 vaccines to support provinces and territories in planning COVID-19 vaccine programs in Canada.