Mr. Speaker, with regard to part (a), Pfizer’s submission provided information that process one was used for clinical trials and process two was used for commercial scale-ups. The residual DNA limit is the same for both processes and is in line with the recommendation from the World Health Organization. The comparability of the vaccine produced by these two processes was demonstrated based on their biological, chemical and physical characteristics.
With regard to part (b), Health Canada was aware of the presence of residual plasmid DNA because in the manufacture of any vaccine, residual elements are part of the standard manufacturing process and may remain. There are strict limits and controls for the presence of these residual fragments to ensure that there is no effect on the safety or effectiveness of the vaccine.
The limit for residual DNA in biologic drugs required by Health Canada for approval is not more than 10 nanograms per human dose. This is in line with the World Health Organization’s recommendation concerning residual DNA in biological drugs and is consistent with the quality limits of other international regulators.
It is important to assess the results using the authorized validated assays performed by the vaccine manufacturers to ensure that the quality of commercial vaccine lots is comparable to that of lots shown to be safe and efficacious in clinical studies.
With regard to part (c), refer to part (b).
With regard to part (d), Health Canada initially authorized the Pfizer-BioNTech COVID-19 mRNA vaccine in December 2020 and subsequently has authorized updated versions, including the most recent vaccine targeting the XBB omicron subvariant in September 2023. Each assessment included a determination that the vaccine met the department's stringent regulatory safety, efficacy and quality requirements for use in Canada.
As a regulator, Health Canada sets quality standards and requirements for manufacturers to follow, including providing comprehensive and detailed information about the vaccine itself and about the manufacturing process. In the manufacture of any vaccine, residual elements that are part of the standard manufacturing process may remain. There are strict limits and controls for the presence of these residual fragments to ensure that there is no effect on the safety or effectiveness of the vaccine.
The simian virus 40, SV40, promoter enhancer sequence was found to be a residual DNA fragment in the Pfizer-BioNTech COVID-19 vaccine. The fragment is inactive, has no functional role and was measured to be consistently below the limit required by Health Canada and other international regulators.
With regard to parts (e) and (f), in the case of the Pfizer-BioNTech COVID-19 vaccine, the full DNA sequence of the Pfizer plasmid was provided at the time of initial filing. The SV40 promoter enhancer sequence was found to be a residual DNA fragment in the Pfizer-BioNTech COVID-19 vaccine. The fragment is inactive, has no functional role and was measured to be consistently below the limit required by Health Canada and other international regulators. Monitoring of the residual DNA fragments is conducted by the manufacturers using methods that have been reviewed and validated by Health Canada as appropriate for its purposes. All Pfizer-BioNTech’s COVID 19 vaccine commercial batches released in Canada complied with the requirements approved by Health Canada, including the residual DNA.
With regard to part (g), refer to part (f).
With regard to part (h), as a regulator of vaccines, Health Canada sets quality standards and requirements for manufacturers to follow, including providing comprehensive and detailed information about the vaccine itself and about the manufacturing process. In the manufacture of any vaccine, residual elements that are part of the standard manufacturing process may remain. There are strict limits and controls for the presence of these residual fragments to ensure that there is no effect on the safety or effectiveness of the vaccine.
With regard to part (i), Health Canada continues to monitor the COVID-19 vaccines to ensure that they continue to meet the highest standards for safety, effectiveness and quality and that their benefits continue to outweigh any potential risks.
With regard to part (j), Health Canada is not considering regulating mRNA vaccines as gene therapy products, as these vaccines cannot modify genes. Gene therapy involves the use of genes as medicine to treat genetic disease where the faulty gene is fixed, replaced or supplemented with a healthy gene so that it can function normally. The new gene has to enter the cell nucleus. The mRNA from the vaccines does not enter the cell nucleus or interact with the DNA at all, so it does not constitute gene therapy. Furthermore, vaccines must meet the high standard of quality, safety and efficacy for medicinal products. Consistent with the international approach to regulating these products, Health Canada will continue to regulate mRNA vaccines as vaccines.
With regard to part (k), Health Canada initially authorized the Pfizer-BioNTech COVID-19 mRNA vaccine in December 2020 and subsequently has authorized updated versions, including the most recent vaccine targeting the XBB omicron subvariant in September 2023.
As a regulator of vaccines, Health Canada sets quality standards and requirements for manufacturers to follow, including providing comprehensive and detailed information about the vaccine itself and about the manufacturing process. In the manufacture of any vaccine, it is expected that there may be variabilities or residual elements that are part of the standard manufacturing process. To manage this, Health Canada requires strict quality limits and controls for the presence of these residual fragments to ensure that the vaccine continues to be safe and that any residual fragments are inactive and have no functional role in the vaccine. All versions of the Pfizer and Moderna vaccines that have been marketed in Canada continue to meet the strict quality standards required by Health Canada. Health Canada takes immediate action should any marketed vaccine product be found to be non-compliant with regulatory standards in Canada.