Scientists have repeatedly refuted the claim that Covid-19 vaccines can alter a person’s genome, but social media posts suggest DNA contamination in the injections could lead to harmful effects such as cancer. This is false; there is no evidence of significant amounts of genetic material in the shots — and even if there were, experts say they could not alter cells.
The claims circulated after University of South Carolina biologist Phillip Buckhaults appeared before a state panel September 13, 2023 to discuss his research on messenger RNA (mRNA) Covid-19 vaccines.
“It’s surprising that there’s any DNA in there and you can kind of work out what it is and how it got there,” Buckhaults said. “And I’m kind of alarmed about the possible consequences.”
In a September 18 post on X, formerly known as Twitter, chiropractor Ben Tapper says: “In other words, this vaccine will forever change your DNA.”
The post shares footage and a quoted excerpt from Buckhaults’s testimony, including claims that DNA in the Covid-19 shots “could be causing some of the rare, but serious, side effects like death from cardiac arrest” and poses “a very real theoretical risk of future cancer in some people.”
Other claims from the panel have circulated in articles and on TikTok, Instagram and Facebook. Some repeat Buckhaults’s claim that “there’s probably about 200 billion pieces of this plasmid DNA in each dose of the vaccine.”
Buckhaults did not cite any research supporting his assertions, but they echo a preprint paper that fact-checking organization Health Feedback debunked in June 2023. Buckhaults later clarified his comments on X.
“The DNA is real, however the risk of this DNA is theoretical. There is no need to panic about past vaccination,” he said in a September 23 post (archived here).
“These vaccines saved a lot of lives. Far more than the number of people who have had medical events subsequent to vaccine. So overall, these vaccines were a win.”
However, University of Michigan virologist Michael Imperiale told AFP that Buckhaults’s claims of DNA contamination are unsupported. US guidelines require testing, and Imperiale said any lots with unacceptable ingredients are withdrawn.
AFP has debunked several claims that Covid-19 vaccines contain DNA, alter people’s genomes and cause cancer.
Vaccine safety
The mRNA vaccines from Pfizer and Moderna differ from traditional vaccines in that they contain instructions for cells to make coronavirus spike proteins, thereby triggering an immune response.
Health Canada previously told AFP that “Covid-19 mRNA vaccines do not include DNA as part of the ingredients.”
“The mRNA never enters the central part (nucleus) of the cell, which is where our DNA (genetic material) is found, and the cells’ DNA cannot be altered by mRNA vaccines,” the department said July 14.
While the ingredient lists for mRNA Covid-19 vaccines do not mention DNA (archived here), Imperiale said he “can’t think of anything dangerous” that would happen if they did.
To affect a person’s genome, he said contaminants would need to enter “dividing cells” — not the muscle or skin cells where the vaccine is introduced.
“For it to cause cancer, it would have to incorporate into the genome known to be involved in cancer and turn on the gene. It doesn’t have a way to do that,” Imperiale said.
David Gorski, a professor of surgery and oncology at the Wayne State University School of Medicine, also said in a September 21 blog post (archived here) that Buckhaults’s claims about potential genetic damage are baseless.
Gorski said the process by which DNA inserts itself into the genome and introduces mutations can only lead to cancer “if the mutation either activates or increases the expression of oncogenes (cancer-causing genes) or inactivates tumor suppressor genes.”
“Sounds scary but is incredibly unlikely,” he said.
Gorski added that there is “zero evidence or biological plausibility to link minuscule amounts of short fragments of DNA to cardiac arrest or sudden death.”
FDA monitoring
The US Food and Drug Administration (FDA) said in a September 27 statement that Covid-19 vaccines “have undergone — and continue to undergo — the most intense vaccine safety monitoring in US history.”
The agency added that both it and the Centers for Disease Control and Prevention (CDC) “stand firmly behind the safety and effectiveness” of the shots.
The CDC says in a fact sheet (archived here) that the FDA “monitors a vaccine product’s quality in real-time by requiring manufacturers to submit samples of each vaccine lot for testing.”
“When vaccines are consistent across lots, FDA can confirm the product remains reliable and safe for use in people,” the document says, adding that the agency conducts regular inspections of the production process.
By contrast, Gorski said in his blog post that Buckhaults’s presentation omits any mention of the “chain of custody and storage conditions” of the vaccine vials tested for DNA.
“If these vials of used-up vaccine containing small amounts of vaccine left over weren’t stored properly, the tendency would be for the RNA to degrade much more rapidly than any DNA, thus apparently elevating the DNA-to-RNA ratio in the solution,” Gorski said.
Pfizer said in an October 3 statement that “the safety and efficacy of our Covid-19 vaccines have been established among hundreds of millions of individuals around the world over the past three years.”
AFP contacted Moderna for comment on its mRNA Covid-19 vaccine, but a response was not forthcoming.
AFP has fact-checked other claims about vaccination here.
