Health Canada responded to questions about COVID-19 vaccination submitted by Conservative MP Collin Carrie, including possible adverse events, the “gene therapy” nature of the mRNA shots, and lingering spike protein. Carrie asked if the Pfizer clinical trials had tested for biomarkers associated with adverse effects related to spike protein in circulation, such as troponin-1 as an indicator for heart damage, and C-reactive protein for inflammation. Health Canada said that blood samples had been collected during the trials and tested for C-reactive protein, and Pfizer is currently conducting testing for troponin-1. No cases of myocarditis following administration of the vaccine were reported in clinical trials, but very rare cases have been reported since the roll-out of the injections. The National Advisory Committee on Immunization recommended that the Pfizer product be given to adolescents and young adults over Moderna’s due to heart inflammation concerns. Studies have found the risk of myocarditis after mRNA vaccination 8 and 30 times greater than the unvaccinated control groups for Pfizer and Moderna products, respectively.
MP Carrie also raised questions about the mRNA technology used in some of the injections and the process to grant them market authorization. Health Canada said that the use of mRNA vaccines against viruses and cancers have been studied for over 15 years, and that the SARS-CoV-2 spike proteins generated by the mRNA injections do not linger in the body. It added that the mRNA and the spike protein generated can remain in the body for extended periods. Moderna’s 2020 filing with the Securities and Exchange Commission (SEC) states that mRNA is considered a gene therapy product by the FDA. Health Canada said that mRNA-based medicines are designed to not irreversibly change cell DNA, but side effects observed in gene therapy could negatively impact the perception of mRNA medicines.
Health Canada also said that the Phase 3 clinical trial for the Pfizer COVID-19 vaccine was conducted in the United States, Turkey, Germany, South Africa, Brazil, and Argentina. The trial is expected to be completed in March this year, and Moderna’s pivotal study was completed in December 2022. Health Canada said that each product “underwent careful scientific review, and met our standards for safety, efficacy and quality.”