Summary of NACI statement of March 8, 2024: Updated guidance on the use of protein subunit COVID-19 vaccine (Novavax Nuvaxovid)

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• Overview
• What you need to know

Overview

• On March 8, 2024, the Public Health Agency of Canada (PHAC) released the National Advisory Committee on Immunization's (NACI) Updated guidance on the use of the protein subunit COVID-19 vaccine (Novavax Nuvaxovid). This guidance is based on current evidence and NACI expert opinion.
• On December 5, 2023, Health Canada authorized the use of Novavax Nuvaxovid XBB.1.5 vaccine for individuals 12 years of age and older as a single dose for those who have previously been vaccinated against COVID-19, and as a 2-dose series for those who have never been vaccinated against COVID-19.

With respect to COVID-19 vaccine products, NACI recommends that:

Individuals in the authorized age group being vaccinated against COVID-19 should receive the most recently updated COVID-19 vaccine. At this time, this is an XBB.1.5 COVID-19 vaccine.

• Either an mRNA (Moderna Spikevax XBB.1.5 or Pfizer-BioNTech Comirnaty XBB.1.5) or protein subunit (Novavax Nuvaxovid XBB.1.5) COVID-19 vaccine can be used in unvaccinated or previously vaccinated individuals who do not have contraindications to the vaccine.

For unvaccinated individuals 12 years of age and over receiving Novavax Nuvaxovid XBB.1.5, NACI's recommended schedule is as follows:

• Unvaccinated individuals who are not immunocompromised and receiving Novavax Nuvaxovid XBB.1.5 may follow a 1-dose schedule.
• For those who are moderately to severely immunocompromised, at least 2 doses of Novavax Nuvaxovid XBB.1.5, with a 4 to 8-week interval between doses, are recommended.

NACI will continue to monitor the evolving evidence and will update guidance as needed.

For the full statement, including supporting evidence, rationale, and additional information on recommended schedules, please see NACI's Updated guidance on the use of protein subunit COVID-19 vaccine (Novavax Nuvaxovid).

What you need to know

• NACI has updated the recommended products to use in vaccination campaigns in light of recent changes to the Novavax Nuvaxovid authorized product.
• Although the new XBB.1.5 formulation protein subunit COVID-19 vaccine has been less widely used compared to mRNA COVID-19 vaccines, there is more evidence and real world use of the original Novavax Nuvaxovid protein subunit COVID-19 vaccine, both within Canada and internationally.
• Since its authorization in Canada in March 2022, the original Novavax Nuvaxovid vaccine has been shown to work well and has a good safety profile. Additional data on the protein subunit vaccine, including how effective it is against JN.1, is expected in the near future.
• With this updated recommendation, either an mRNA or protein subunit COVID-19 vaccine can now be used for people 12 years of age and over, whether they have been previously vaccinated or are unvaccinated.
• The Novavax Nuvaxovid XBB.1.5 vaccine is authorized as 2 doses for unvaccinated individuals 12 years of age and over. However, NACI is recommending that it may be used as a single dose for those who are not moderately to severely immunocompromised. The use of 1-dose is consistent with authorization for use in Europe and also with the authorized schedules and recommendations for mRNA vaccines in Canada.
• As with mRNA COVID-19 XBB.1.5 vaccines, For those who have previously been vaccinated with a primary series, 1-dose of Novavax Nuvaxovid XBB.1.5 is recommended, as is the case with mRNA COVID-19 XBB.1.5 vaccines.
• Similar to mRNA vaccines, cases of myocarditis and/or pericarditis have rarely been reported following the administration of Novavax Nuvaxovid original. Based on experience with mRNA COVID-19 vaccines, the risk of myocarditis and/or pericarditis is expected to be lower with the use of a 1-dose schedule.
• As with all COVID-19 vaccines, Novavax Nuvaxovid may be given simultaneously with or at any time before or after, non-COVID-19 vaccines (including live and non-live vaccines).

For more information on 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.