Regulatory Decision Summary for Spikevax Bivalent

To support authorization of the Spikevax Bivalent™ booster dose, the immune response and safety data (cut-off date of 2022-04-27) of individuals immunized with the new Spikevax Bivalent™ were compared to the approved Spikevax ™ Original vaccine.

Eligible adults over 18 years of age (814 individuals both male and female) were included in the study, a total of 437 individuals received the Spikevax Bivalent™ and 377 individuals received the comparator vaccine Spikevax ™ Original. The immune responses were evaluated in these two groups against the Original SARS-CoV-2 virus or against the Omicron BA.1 virus. The results presented indicate that the new Spikevax Bivalent™ vaccine induces similar responses to the Original virus and significantly higher responses to the Omicron BA.1 virus when compared to the Spikevax™ Original approved vaccine.

Overall, the findings indicate that the Spikevax Bivalent™ provides better immune response to the Omicron BA.1. Results of exploratory analyses suggest that a second booster with Spikevax Bivalent would provide a superior neutralizing antibody response against BA.4/5 compared to a second booster with Spikevax Original. Planned post-market studies are expected to provide additional validation of the immune response.

At the time of analysis, participants were followed-up for safety for approximately 6 weeks after receiving the booster. Safety and immune response data from 3-months and 6-months of follow-up will be provided to Health Canada when available and were requested as part of the Terms and Conditions required for marketing authorization. The frequency and severity of the solicited ARs was similar between the two groups; the most common local solicited ARs (≥10%) were pain at the injection site (77.9% and 77.2%) and axillary swelling (17.1% and 19.6%) in the Spikevax Bivalent™ and Spikevax ™ Original groups, respectively. The commonest (≥10%) solicited systemic ARs were fatigue (54.9% and 51.4%), headache (43.9% and 41.1%), myalgia (39.6% and 38.6%), arthralgia (31.1% and 31.7%), chills (23.8% and 21.1%) and nausea/vomiting (10.3% and 10.0%) in the Spikevax Bivalent™ and Spikevax ™ Original groups, respectively.

No new safety concerns have been identified in studies when compared to the currently approved Spikevax mRNA vaccine. No deaths or Adverse Events of Special Interest (AESI) including cases of myocarditis or pericarditis occurred. Safety concerns remain as those captured in the Spikevax Original label.

The exact timing of the booster doses and appropriate populations to administer booster doses to will depend on a variety of factors, including the local epidemiological contexts, which are continually evolving and may vary between provinces and territories.
A Core Risk Management Plan (RMP) and a Canadian RMP Addendum was included in the submission for Spikevax Bivalent. 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 monitoring (pharmacovigilance) activities and risk minimization measures based on the known safety profile of Spikevax (original). 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, monthly safety summary reports on the vaccine will be provided to Health Canada.

Based on the totality of the information, the benefit-risk profile for a 50 µg booster dose of Spikevax Bivalent™ is considered favourable in individuals 18 years of age or older.

“For further details about Spikevax Bivalent, please refer to the Product Monograph, approved by Health Canada and available through the Drug Product Database.”

For more information on Health Canadas decision, please view the Summary Basis of Decision.