Regulatory Decision Summary for Spikevax

COVID-19 is a serious and potentially life-threatening disease in children. Vaccination is one of the most effective ways to protect children against the disease.

To support authorization of Spikevax in children 6 to 11 years of age, safety, immunogenicity, and efficacy data from the ongoing study P204 (Part 2) were provided. At the time of the data snapshot (November 10, 2021), a total of 4,011 participants (6 to 11 years of age) were randomized 3:1 to receive 2 doses (50 µg each dose) of Spikevax or a saline placebo 28 days apart. The median follow-up duration was 82 days after dose 1 and 51 days after dose 2. 

Vaccine efficacy in children 6 years to 11 years of age was inferred by comparing the immune response (SARS-CoV-2 50% neutralising titers and seroresponse rates) 28 days after the second dose. The comparison was conducted in a subset of children 6 to 11 years of age (Study P204; N=320) and in participants 18 through 25 years of age from the pivotal study (Study P301; N=295) that established the efficacy of Spikevax. The results showed that the immune response to Spikevax in children 6 -11 years of age (50 µg each dose) was comparable to that seen with Spikevax in subjects 18 to 25 years of age (100 µg each per dose), supporting the vaccine efficacy in children 6 to 11 years of age.

No emergent safety concerns were identified in the study. The most frequently reported adverse reactions following administration of Spikevax were pain at the injection site (94.8%), fatigue (64.5%), headache (54.3%), chills (30.3%) and myalgia (28.2%); other reactions included redness and swelling at the injection site, nausea, vomiting, swollen or tender lymph nodes under the arm, fever, and muscle and joint pain. The adverse reactions were usually mild or moderate and improve within a few days of vaccination. No serious adverse events were assessed as related to study vaccine. There were no deaths, no cases of anaphylaxis, and no cases of myocarditis or pericarditis reported during the study period.

The evidence indicates that the immunogenicity/efficacy and safety of Spikevax in children 6 to 11 years of age are similar to those in young adults (18 to 25 years of age). Therefore, the benefit-risk profile of Spikevax is considered favourable for use as a 2-dose series (50 µg each dose, 4 weeks apart) in children 6 to 11 years of age.

There are some uncertainties or limitations at the current time, including unavailable longer-term safety, immunogenicity and efficacy data; the uncertainty around the risk of very rare events such as myocarditis and pericarditis post-vaccination in this age group; the safety and efficacy in subjects with severe comorbidities or who are immunocompromised. The limitations are mitigated by Terms and Conditions associated with the authorization, by labelling and the Risk Management Plan (RMP).

The RMP was reviewed and considered acceptable. The RMP identified appropriate monitoring (pharmacovigilance) activities and risk minimization measures based on safety profile of this vaccine. This included providing information in the product monograph and identifying special populations where more data is needed. In addition to regulatory requirements for post-market monitoring and prioritized reporting of adverse events following immunization, safety summary reports will be provided on a regular basis to Health Canada for review. Results related to safety and effectiveness from ongoing and planned studies, including the pediatric population, will be submitted as they become available.

Spikevax is therefore recommended for authorization under Food and Drug Regulations for drugs for use in relation to COVID-19, for active immunization against coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in individuals 6 years of age and older.