Fact Check: Pfizer COVID-19 Vaccine Shows NO DNA "Contamination," Permanent Genetic Changes Or Death From Cardiac Arrest

Fact Check

  • by: Ed Payne
Fact Check: Pfizer COVID-19 Vaccine Shows NO DNA "Contamination," Permanent Genetic Changes Or Death From Cardiac Arrest No DNA Changes

Is the Pfizer mRNA COVID-19 vaccine "contaminated" with a type of DNA that causes permanent genetic changes in vaccinated people or leads to death due to cardiac arrest? No, that's not true: The Food and Drug Administration (FDA) told Lead Stories that residual DNA found in Pfizer's COVID shot has produced "no safety concerns." Additionally, an infectious disease expert said no data "indicate that there is a sudden death increase in the vaccinated over the unvaccinated population when the populations are comparable in age distribution."

The claim appeared in a post and video (archived here) published on Facebook by Michelle Moore on September 20, 2023. The post's caption said:

Dr. Buckhaults testimony before SC DHEC [South Carolina Department of Health and Environmental Control]. This must be shared! This is all the truth and transparency you need.

This is what the post looked like on Facebook at the time of writing:


(Source: Facebook screenshot taken on Mon Nov 20 16:27:56 2023 UTC)

The video

In the video, Phillip Buckhaults, a University of South Carolina professor who has a doctorate in biochemistry and molecular biology, testifies before the South Carolina Senate Medical Affairs Committee on September 12, 2023. About 48 seconds into the clip on Facebook, a slide appears, summarizing his main points. It says:

The Pfizer mRNA vaccine is contaminated with the plasmid DNA vector that was used as the template for in vitro transcription reaction.

this DNA could be the cause of some of the rare but serious side effects like death from cardiac arrest.

The DNA can and likely will integrate into the genomes of transfected cells.

There is a very real hazard for genome modification of long-lived somatic cells, which could cause sustained autoimmune attack toward that tissue.

There is also a theoretical risk of future cancer, depending on the piece of DNA and site of integration.

Buckhaults' claims are not peer-reviewed but they closely parrot a preprint paper (also not peer-reviewed) endorsed by Byram Bridle, an Ontario Veterinary College professor of viral immunology who is well-known in antivaccine communities and whose claims have been previously debunked by Lead Stories.

Food and Drug Administration

Cherie Duvall-Jones, a press officer at the FDA, provided the agency's response to the claims in the social media video. In a November 20, 2023, email, it said:

With over a billion doses of the mRNA vaccines administered, no safety concerns related to the sequence of, or amount of, residual DNA have been identified. In general, with regard to the mRNA vaccines, while concerns have been raised previously as theoretical issues, available scientific evidence supports the conclusion that the vaccines are safe and effective. The FDA stands behind its findings of quality, safety, and efficacy for the mRNA vaccines.

Additional questions may be directed to the manufacturer.


In another November 20, 2023, email to Lead Stories, a Pfizer spokesperson disputed the assertions made during Buckhaults' testimony before the committee. Pfizer's response said:

There is no evidence to support claims that the Pfizer-BioNTech COVID-19 vaccine contains plasmid DNA that could potentially impact a person's DNA or be a theoretical cancer risk.

Plasmid vs. chromosomal DNA

The distinction between chromosomal DNA and plasmid DNA, as mentioned by Buckhaults, lies in the fact that plasmid DNA exclusively carries supplementary genes that are dispensable for the organism's essential functions. In contrast, chromosomal DNA encompasses all the requisite information for the organism's growth, development, and reproduction. In essence, chromosomal DNA serves as the comprehensive repository of vital genetic instructions.

Also, the Centers for Disease Control and Prevention (CDC) website says COVID-19 vaccines do not alter DNA:

FACT: COVID-19 vaccines do not change or interact with your DNA in any way.

Both messenger RNA (mRNA) and protein subunit COVID-19 vaccines work by delivering instructions (genetic material) to your cells to start building protection against the virus that causes COVID-19.

After the body produces an immune response, it gets rid of all the vaccine ingredients just as it would get rid of any information that cells no longer need. This process is a part of normal body functioning.

The genetic material delivered by mRNA vaccines never enters the nucleus of your cells, which is where your DNA is kept, so the vaccine does not alter your DNA.

Learn more about how COVID-19 vaccines work.

Pfizer continued its response, saying the plasmid DNA that Buckhaults said has "contaminated" the Pfizer COVID vaccine is "commonly used in the pharmaceutical industry" as "starting material." The Pfizer spokesperson added:

The Pfizer-BioNTech COVID-19 vaccine has been reviewed by multiple regulatory authorities, including the EMA [European Medicines Agency] and U.S. Food and Drug Administration (FDA), and advisory bodies globally and has met all safety and quality control guidelines. 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 World Health Organization and FDA for biological products.

It is important to note that similar quality standards regarding residual DNA are applied to other vaccines. Small amounts of residual DNA can be found in several approved vaccines, including influenza and hepatitis vaccines, which have been administered globally for more than 30 years.

Infectious disease expert

Dr. William Schaffner, a professor of medicine in the division of infectious diseases at Vanderbilt University Medical Center, told Lead Stories in a November 20, 2023, email that the "Pfizer statement is clear and straightforward." He continued:

It is reassuring that only viral fragments are detected and that their presence is well-known to global regulatory agencies including the EMA and the US FDA among others, that have assessed the safety of the Pfizer COVID vaccines, both pre-licensure as well as post-licensure.

Additionally, Schaffner said in a November 20, 2023, phone interview that the same applies to the claim of death from cardiac arrest due to the Pfizer vaccines:

I've seen no data presented at the CDC, from the large databases -- from the Department of Defense, the Veterans Administration, and others -- that indicate that there is a sudden death increase in the vaccinated over the unvaccinated population, when the populations are comparable in age distribution, sex and the like.

Read more

Other Lead Stories debunks of claims about COVID vaccines and deaths can be read here.

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Lead Stories is working with the CoronaVirusFacts/DatosCoronaVirus Alliance, a coalition of more than 100 fact-checkers who are fighting misinformation related to the COVID-19 pandemic. Learn more about the alliance here.

  Ed Payne

Ed Payne is a staff writer at Lead Stories. He is an Emmy Award-winning journalist as part of CNN’s coverage of 9/11. Ed worked at CNN for nearly 24 years with the CNN Radio Network and CNN Digital. Most recently, he was a Digital Senior Producer for Gray Television’s Digital Content Center, the company’s digital news hub for 100+ TV stations. Ed also worked as a writer and editor for WebMD. In addition to his journalistic endeavors, Ed is the author of two children’s book series: “The Daily Rounds of a Hound” and “Vail’s Tales.” 

Read more about or contact Ed Payne

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