Regulatory Decision Summary for Nuvaxovid

COVID-19 is caused by the SARS-CoV-2 following infection of the respiratory tract. While most patients will have mild symptoms of fever, cough, fatigue and shortness of breath, in some patients the infection will cause lung injury leading to acute respiratory distress syndrome and death. Other symptoms also include loss of smell and taste, as well as long COVID due in part to viral persistence which may cause long-term tissue damage in the lungs, brain, and heart.

Vaccine efficacy of Nuvaxovid based on the prevention of COVID 19 has been established at more than 89% in over 24,000 adults after the primary series of vaccination. Immunogenicity responses, as measured by the level of neutralizing antibodies capable of preventing SARS-CoV-2 replication, however, progressively decreased by more than 8-fold after 6 months since the primary series of vaccination.

A third (booster) dose at least 6 months after the primary series was shown to induce a robust immune response in a total of 866 healthy adult participants, during a Phase II and a Phase III study. There were approximately 3-fold higher neutralizing antibody titers following the booster dose as compared to those observed after the primary series of vaccination. Although vaccine efficacy following the booster dose was not determine, the immune response observed is expected to enhance protection against COVID-19 in vaccinated individuals.

The administration of the vaccine Nuvaxovid was well tolerated following the primary series of vaccination in adults, with adverse reactions generally of mild to moderate in severity and duration of less than 2 days. The most frequent adverse reactions were injection site tenderness, injection site pain, fatigue, myalgia, headache, malaise, join pain and nausea or vomiting. Other adverse reactions which may occur include joint pain, injection site redness and swelling, fever and chills.

Following the booster vaccination in over 2,000 adult participants, the frequencies and severity of these adverse reactions increased, but with most events being mild to moderate in severity. Participants aged 65 years and older generally had fewer and less severe adverse reactions. There were two participants (<0.1%) that experience very severe reactions (injection site pain, tenderness, malaise, muscle pain, headache) that resolved within 3 to 4 days. Serious adverse events reported after the booster dose were considered unrelated to vaccination.

As with all vaccines, rare cases of severe allergic reactions may occur within 30 minutes following vaccination. Inflammation of the heart such as myocarditis or pericarditis may also occur in at risk individuals. In both cases, vaccinated individuals require medical attention following vaccination.

A Core Risk Management Plan (RMP) and a Canadian RMP Addendum were included in the submission for Nuvaxovid. The RMP is designed to describe known and potential safety issues, to present the monitoring plan and when needed, to describe measures that will be put in place to minimize risks associated with the product. Upon review, the RMP was considered to be acceptable and identified appropriate monitorin (pharmacovigilance) activities and risk minimization measures based on the safety profile of the product. This included providing information in the product monograph and identifying populations where more data are needed. The RMP will be updated to reflect additional safety information as this is collected. In addition to regulatory requirements for post-market monitoring and prioritized reporting of adverse events following immunization, safety reports on the vaccine will be provided to Health Canada. Results related to safety and effectiveness from ongoing and planned studies will be submitted as they become available.

Taking the sum of evidence presented, the benefit profile in the use of the vaccine Nuvaxovid as a booster dose is considered favorable in adults aged 18 years and older, with risk mitigations described in the Product Monograph (PM). Novavax Inc. is committed in updating the PM for NUVAXOVID with safety and vaccine efficacy or effectiveness data on an ongoing basis.

For further details about Nuvaxovid (COVID-19 Vaccine [Recombinant protein, Adjuvanted]), please refer to the Product Monograph, approved by Health Canada and available through the Drug Product Database.