Mr. Speaker, the health and safety of Canadians are Health Canada’s top priority, and before the initial authorization of the Pfizer-BioNTech vaccine, COMIRNATY, the department completed a rigorous scientific review of the product’s safety, efficacy and quality. Following authorization, Health Canada remained active in discussions with international partners in assessing the quality, safety and efficacy of all COVID 19 vaccines.
Health Canada also collaborates with international partners; the Public Health Agency of Canada, PHAC; the National Advisory Committee on Immunization, NACI; and provincial/territorial public health authorities in monitoring the safety of vaccines authorized for use in Canada. The risk-based decisions made by Health Canada on the COVID-19 mRNA vaccines are based on sound scientific evidence and are also in line with those of other countries, international guidelines, sound regulatory principles, and good regulatory practices.
Health Canada is aware of concerns surrounding SV40. In July 2023, through clarification requests, Health Canada evaluated the presence of the SV40 promoter-enhancer sequence in the plasmid used to prepare the Pfizer-BioNTech COVID-19 vaccine, COMIRNATY, as well as in residual DNA as a manufacturing impurity in the final vaccine product. Clarification requests are routinely issued during submission review to seek clarifications on various aspects of the file. Health Canada submitted a clarification request to Pfizer seeking additional information related to the SV40 sequences. Pfizer provided a reply to address all of Health Canada’s questions. Please note that communications between Health Canada and manufacturers related to the manufacturing and control of a vaccine are considered confidential business information that cannot be disclosed.
As previously indicated, the presence of a fragment of the SV40 sequence is not the same as the presence of the whole virus itself. The SV40 promoter-enhancer sequence fragment is inactive and has no functional role. The presence of the SV40 promoter-enhancer sequence in the COVID-19 vaccines is considered as low risk, as the levels of this residual DNA fragment are consistent with international regulators and are below the WHO recommended limit of 10 ng/dose.
To date, over three billion doses of COMIRNATY have been administered worldwide, including over 69 million doses in Canada: https://health-infobase.canada.ca/covid-19/vaccine-administration/. No safety signals related to the residual SV40 DNA fragment have been detected. When new safety issues are confirmed by the department, Health Canada takes action, which may include communicating new risks to Canadians and health care professionals or changing the recommended use of the product.