MEDICAL ADVISORY: Information on the use of Novavax Nuvaxovid COVID-19 vaccine and preferential recommendations   

Issued by:  Azim Kasmani, MD, FRCPC, Associate Medical Officer of Health

Health Canada has authorized the Novavax Nuvaxovid COVID-19 vaccine for people 18 years of age and over. In alignment with the National Advisory Committee on Immunization (NACI’s) recommendations the Ministry of Health has updated their guidance for health care providers administering the COVID-19 vaccines (see Chapter 6).

What you need to know about Novavax Nuvaxovid

• It is the first recombinant protein subunit COVID-19 vaccine authorized for use in Canada
  • It is a two dose primary series
  • For the most robust and durable immune response and higher vaccine effectiveness NACI recommends an 8 week interval between first and second dose
• The minimum interval between first and second doses is 21 days
• Reported side effects from the vaccine are typically mild (i.e., fatigue, headache and muscle pain) and resolve within one or two days. Side effects occurred more frequently after the second dose and were more common in adults 18 to 64 years of age compared to older adults
• Rare cases of myocarditis and/or pericarditis have been reported following the administration of the vaccine, but there is not yet enough information to determine if cases of myocarditis and/or pericarditis are related to the vaccine
  • NACI and the Ministry of Health recommend waiting 8 weeks between the first and second doses of COVID-19 vaccine to enhance immune response and to further reduce the low risk of myocarditis and/or pericarditis in certain populations
• Clinical trial data available show Novavax Nuvaxovid is highly efficacious in preventing confirmed symptomatic COVID-19 disease in the short term. However, the duration of protection is not yet known and there is currently no data on the efficacy or effectiveness of the vaccine against the Delta or Omicron variants, as clinical trials were conducted before the emergence of those variants.

Recommendations for a COVID-19 primary series

• NACI continues to preferentially recommend that a complete primary series of an mRNA COVID-19 vaccine should be offered to individuals in the authorized age group without contraindications to the vaccine
  • mRNA COVID-19 vaccines provide excellent protection against severe illness and hospitalization and have well-known safety profiles
• Novavax Nuvaxovid may be offered to individuals in the authorized age group without contraindications to the vaccine who are not able or willing to receive an mRNA COVID-19 vaccine
  • Individuals may receive a heterologous (mixed) primary series (one dose of the Novavax Nuvaxovid and one dose of another COVID-19 vaccine)
  • If receiving a heterologous primary series with Novavax Nuvaxovid, informed consent should include a discussion of the benefits and potential risks given the currently limited data on mixed schedules with this vaccine
  • Niagara Region Public Health recommends an 8 week interval between heterologous doses in a primary series

Novavax Nuvaxovid as a booster dose

• The Ministry of Health allows the administration of the Novavax Nuvaxovid vaccine as a booster dose to adults without contraindications to the vaccine who are not able or willing to receive an mRNA COVID-19 vaccine, regardless of which vaccines were received in the primary series
• NACI recommends that a booster dose of Novavax Nuvaxovid may be offered ≥6 months after completion of a primary COVID-19 vaccine series
  • The minimum interval between the completion of the primary series and the booster dose is 84 days as per the Ministry of Health
• This recommendation is off-label, as the Novavax Nuvaxovid is not currently authorized for use as a booster dose in Canada
  • Informed consent should include a discussion about what is known and unknown about the benefits and potential risks of the use of the Novavax Nuvaxovid as a booster dose, including the off-label status of this recommendation

Recommendations for vaccination with Novavax Nuvaxovid following COVID-19 infection

• For individuals who have had a COVID-19 infection before starting or completing their primary vaccine series, NACI recommends their next dose eight weeks after symptoms onset or after testing positive (if asymptomatic)
• For individuals who are eligible for a booster and who have had a COVID-19 infection after completing their primary vaccine series, NACI recommends their next dose three months after symptom onset or after testing positive (if asymptomatic) and if it has been at least six months since completing the primary series
• The Ministry of Health recommends individuals wait 1 to 6 months following COVID-19 infection to receive their next dose of COVID-19 vaccine. Health care providers should consider age, doses received and health status when discussing optimal timing with patients.

Special populations

• There is currently limited evidence on the use of the Novavax Nuvaxovid in populations not included in the clinical trials. Administering Novavax Nuvaxovid in these populations may proceed with appropriate health teaching and informed consent; however, mRNA COVID-19 vaccines do have established safety profiles and effectiveness in these populations and are the preferred vaccine.
• For individuals with serious polyethylene glycol (PEG) allergy or previous serious allergic reaction to an mRNA vaccine precluding vaccination with mRNA vaccines, the Novavax Nuvaxovid may be the preferred product for vaccination, based on consultation with an allergist or other appropriate physician
• A component of the Novavax Nuvaxovid that may cause type 1 hypersensitivity reactions is Polysorbate 80. Allergic reactions to Polysorbate 80 are rare. Polysorbate 80 is found in products such as medical preparations (e.g., vitamin oils, tablets, and anticancer agents) or cosmetics.

Simultaneous administration with other vaccines

• Novavax Nuvaxovid may be given simultaneously with (i.e., same day), or at any time before or after, non-COVID-19 vaccines (including live and inactivated vaccines)
• If vaccines are being provided simultaneously, then informed consent should include a discussion of the benefits and risks of simultaneous vaccine administration given the limited data available on administration of the Novavax Nuvaxovid simultaneously with other vaccines

Local availability of Novavax Nuvaxovid

• Ontario is expecting to receive its first shipment in early April, 2022
• If you have patients interested in accessing a dose of Novavax Nuvaxovid, please advise them to call Niagara Region Public Health’s COVID-19 Info-Line at 905-688-8248, press 7, then 2, to be assessed for eligibility and, if eligible, added to a waitlist. There is no guarantee that the vaccine will be available.

More information

• Call the COVID-19 Primary Care Info-Line at 905-688-8248 (press 7, then 1 for physicians). The info-line is open Monday to Friday, 8:30 a.m. to 4:15 p.m.
• Niagara Region Public Health’s Getting vaccinated webpage
• Product monograph for Novavax Nuvaxovid COVID-19 vaccine
• Staying Up to Date with COVID-19 Vaccines: Recommended Doses – Ministry of Health