People on social media are using a screenshot from an article to claim Health Canada concluded that a cancer-causing virus "gene sequence" from simian virus 40 (SV40) exists in Pfizer-BioNTech COVID-19 vaccines. This is misleading. The public health agency says the vaccine does not contain SV40 virus, but instead an inactive fragment of that virus DNA, known as SV40 promoter enhancer, that is not harmful to humans.
Several , formerly known as Twitter, posted claims saying Pfizer-BioNTech COVID-19 vaccines are contaminated with the SV40 DNA sequence, and that this DNA sequence "promotes the development of cancer."
"If Pfizer truly cared about humanity…why … didn’t they disclose that their vaccines were contaminated with the SV40 Gene Sequence that’s known to promote CANCER?" earlier this month.
The user attached a screenshot of the headline of , a New York-based international newspaper and media company that has been known to publish . The headline reads, "EXCLUSIVE: Health Canada Confirms Undisclosed Presence of DNA Sequence in Pfizer Shot."
The article said Health Canada confirmed the presence of the SV40 DNA sequence in the Pfizer COVID-19 vaccine, and that some scientists say the DNA sequence has the potential to cause cancer, while others say it poses little to no threat.
Rating: Misleading
Claims that COVID-19 vaccines are harmful have spread since they first became available, and this claim is based on a false narrative that these vaccines contain DNA particles that could alter recipients' genetics.
Health Canada spokeswoman Anna Maddison said SV40 was not found in the Pfizer COVID-19 vaccine. However, residual DNA fragments of the SV40 promoter enhancer sequence, which is used during the manufacturing process of the vaccine, was found.
She said the claims of a link between the presence of the SV40 promoter enhancer sequence and an increased risk of cancer are "unfounded."
"The Pfizer-BioNTech COVID-19 vaccine does not contain simian virus 40 (SV40)," she said in a statement.
"The presence of the SV40 promoter enhancer sequence is not the same as the presence of the whole virus itself."
SV40 found in polio vaccines
COVID-19 mRNA vaccines are created using plasmid DNA, which is a circular fragment of DNA, according to the
In the 1960s, scientists discovered that , a virus found in monkeys, had contaminated polio vaccines administered in the late 1950s and early 1960s.
While the virus itself is associated with cancer, there is that polio shots caused cancer, and contains the SV40 virus, according to the U.S. Centers for Disease Control and Prevention.
Strict regulations
Health vaccine in December 2020 and has authorized updated versions of that vaccine since then, including the targeting the Omicron XBB.1.5 subvariant in September 2023.
of each new vaccine to determine whether the vaccine meets the department's stringent regulatory requirements to be approved for use in Canada after making sure it's safe and effective.
Health Canada said it sets quality standards and requirements for vaccine manufacturers, 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," Maddison said.
"To manage this, Health Canada requires to ensure that the vaccine continues to be safe, and that any residual fragments are both inactive and have no functional role in the vaccine."
Maddison said SV40 promoter enhancer sequence was found to be a residual DNA fragment in the Pfizer vaccine, but this fragment is not harmful.
"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," she said.
"Any claims that the presence of the SV40 promoter enhancer sequence is linked to an increased risk of cancer are unfounded. There is also no evidence to support that the presence of the full SV40 in any vaccine increases the risk of cancer or the acceleration of cancer in individuals."
COVID-19 vaccine is safe
Pfizer Canada spokeswoman Christina Antoniou said SV40, which is a naturally occurring virus, is not included in either starting materials, plasmid DNA or in the final product of the Pfizer COVID-19 vaccine.
"The Pfizer-BioNTech COVID-19 vaccine has been reviewed by multiple regulatory authorities, including the EMA and U.S. Food and Drug Administration (FDA), and advisory bodies globally and has met all safety and quality control guidelines," Antoniou said in a statement.
"These agencies approved our COVID-19 vaccine with established specifications for development and manufacturing, including a validated method for assessment of residual DNA outlined by the and FDA for biological products."
Sources
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