There are no genetically modified organisms in the COVID-19 mRNA vaccines; no evidence these vaccines modify our DNA

Unapproved genetically modified organisms in the COVID-19 mRNA vaccines could permanently change our DNA
Factually inaccurate: There are no genetically modified organisms in the COVID-19 mRNA vaccines.
Inadequate support: The studies cited to support the claim that vaccine mRNA can modify the human genome are unrelated to vaccination or didn’t actually find any DNA modification. There’s no reliable evidence showing that DNA in vaccines integrates into our DNA or increases the risk of cancer. In fact, several vaccines predating COVID-19 vaccines contain DNA, such as the chickenpox vaccine. These have been shown to be safe.
Concerns over the potential health effects of residual DNA in biological products like vaccines aren’t new or unknown to regulatory agencies. Regulatory agencies like the U.S. Food and Drug Administration have recommended specific limits on the amount of residual DNA in a vaccine. DNA-containing vaccines, such as the chickenpox vaccine—a live attenuated vaccine containing a DNA virus—have also been widely used before the pandemic and have been shown to be safe.

FULL CLAIM: “Australian GP sues Pfizer and Moderna over unapproved GMOs in mRNA Covid vaccines. Dr Julian Fidge is seeking an injunction to stop the distribution of the mRNA Covid vaccines. But the human genome could already be permanently altered.”; “In tests conducted on the mRNA monovalents and bivalents, genomics expert Kevin McKernan found dangerously excessive levels of DNA contamination”


In November 2023, Gentry Gevers, host of the Break Away USA podcast, posted a screenshot of a tweet by journalist Rebekah Barnett on Instagram that read “Australian GP sues Pfizer and Moderna over unapproved GMOs in mRNA Covid vaccines”. It also claimed “the human genome could already be permanently altered”.

The tweet is a brief summary of an article published by Barnett in July 2023 on her blog Dystopian Down Under, revolving around a lawsuit brought against Pfizer and Moderna by Australian primary care physician Julian Fidge. Fidge seeks to stop further distribution of the vaccines in Australia, alleging that the vaccines contain “unapproved GMOs”. Both companies have challenged the injunction.

Fidge has promoted ivermectin as a COVID-19 treatment, despite the lack of reliable clinical evidence to support this, and has posted claims on social media suggesting that COVID-19 vaccines are deadly. Fidge was banned from prescribing certain drugs of dependence in December 2022, after the Medical Board of Australia found his practice had enabled a patient’s drug dependence, although this ban has been suspended following a temporary stay granted by an appeals court.

In this review, we discuss a few of the primary claims present in the Barnett article and demonstrate why they are inaccurate and misleading.

There are no GMOs in COVID-19 mRNA vaccines

Health Feedback reached out to the Therapeutic Goods Administration, Australia’s regulator for pharmaceutical products, regarding Fidge’s claim about GMOs in the COVID-19 mRNA vaccines.

In an email, a spokesperson for the Office of the Gene Technology Regulator stated that:

“COVID-19 mRNA vaccines do not meet the definition of a GMO in the Gene Technology Act 2000 so do not require a licence from the Gene Technology Regulator. The vaccines do not contain a GMO.”

Australia’s Office of the Gene Technology Regulator defines a GMO (genetically modified organism) as:

  • “a plant, animal or other organism that has been modified using gene technology
  • an organism that has inherited modified traits from a GMO.”

COVID-19 mRNA vaccines don’t contain organisms. As such, the claim that they contain “unapproved GMOs” is inaccurate. One example of a COVID-19 vaccine that does contain a GMO and is regulated as such is the AstraZeneca-Oxford COVID-19 vaccine, as it uses a modified adenovirus vector to deliver the genetic material of the spike protein into cells.

While gene technology is also involved in making the COVID-19 mRNA vaccines, notably recombinant bacteria as we will explain below, the vaccines don’t contain the bacteria themselves.

The role of GMOs in COVID-19 mRNA vaccine production

Developing certain desirable traits in plants and animals, such as seedless fruits and intelligence in working dogs, is a human practice that has spanned centuries. Before gene technology was developed however, humans relied on selective breeding (artificial selection) to achieve this aim.

Apart from making it easier and faster to achieve certain traits in plants and animals, gene technology has been indispensable to medical advances. For instance, large-scale production of human insulin (a sugar-regulating hormone) is possible thanks to such technology. Insulin is critical for people with type I diabetes, whose bodies are unable to produce enough of the hormone. Type I diabetes can lead to fatal consequences if untreated.

An article by the American Diabetes Association explains that before this was possible, insulin from the pancreas of cattle and pigs was used for such patients, which occasionally led to allergic reactions.

Nowadays, we can obtain recombinant human insulin by inserting the genetic material encoding human insulin into a plasmid (a circular DNA molecule), and then inserting the plasmid into the bacterium Escherichia coli or baker’s yeast (Saccharomyces cerevisiae)[1]. The bacterial or yeast cells carrying the plasmid will then produce insulin.

The manufacturing process for COVID-19 mRNA vaccines shares some similarities with the process for making recombinant human insulin. The Pfizer vaccine manufacturing process was detailed in a New York Times article, explaining that the genetic material for the SARS-CoV-2 spike protein is mass-produced by inserting it into a plasmid, which is then inserted into E. coli.

E. coli divides every 20 minutes, provided laboratory conditions are optimal, allowing very large amounts of plasmid to be generated relatively quickly[2].

The DNA is then harvested from the bacteria and cut to isolate the segment containing the spike protein’s genetic material. This segment is then transcribed into mRNA.

Because of the manufacturing process, a certain amount of DNA still gets left behind in the vaccine. Regulatory agencies, like the U.S. Food and Drug Administration, have recommended limits on the amount of residual DNA in biological products like vaccines, as they are aware of potential health concerns related to residual DNA.

However, Barnett’s claim that there is a “dangerously excessive” level of residual DNA in COVID-19 mRNA vaccines, citing the findings of “genomics expert Kevin McKernan” as evidence, is inaccurate.

McKernan’s findings about residual DNA were examined in two reviews from Health Feedback—in both reviews, we concluded that while McKernan and colleagues may have detected DNA in the vaccines, they offered no reliable evidence that the amount of DNA had exceeded the limits recommended by regulatory agencies. In fact, one of the tests performed by McKernan actually found that residual DNA levels in the Pfizer and Moderna vaccine vials tested were well below recommended limits, as we pointed out in this review.

No evidence that COVID-19 mRNA vaccines modify our DNA

Misinformation surrounding the presence of DNA in vaccines has existed long before the COVID-19 pandemic, as an early Health Feedback review documented. Like early iterations of such misinformation, Barnett’s article plays up fears that COVID-19 vaccine mRNA can modify our DNA, citing various studies that purportedly support this claim.

She cited a study allegedly showing the “Pfizer Covid vaccine mRNA is able to enter the human liver cell line and reverse transcribe into DNA in vitro”. However, this study, conducted by Alden et al.[3] at Lund University in Sweden, comes with major caveats, which Health Feedback reported on in March 2022.

Experts pointed out that the experimental system used was artificial, as the researchers used a liver cancer cell line, which is more likely to overproduce an enzyme used for reverse transcription (making DNA from RNA) compared to healthy cells. The researchers also used much higher doses of vaccine in the experiment than the dose administered to adults.

Furthermore, the study didn’t find reverse-transcribed DNA entering the nucleus, much less integrating into the cells’ DNA.

Barnett also went on to cite two other studies purportedly supporting the claim. But a closer reading of these studies indicates that neither study shows vaccine mRNA modifying the human genome. In fact, one is a preprint (a research paper that hasn’t yet been peer-reviewed) showing spike mRNA in the nucleus of human cells during infection, not vaccination.

The other study found that mice could inherit certain immunological traits from their parents that had been injected with lipid nanoparticles[4]. This type of nanoparticle is used to encase vaccine mRNA.

However, the researchers didn’t find that the lipid nanoparticles had modified the mice’s DNA. Instead, they proposed that this was the result of DNA methylation:

“The mechanism of inheritance also remains to be determined. Likely, it is partially mediated through DNA methylation changes that interferons and other inflammatory cytokines might have induced in this case. DNA methylation-based mode of inheritance has recently been proposed with the transgenerational inheritance observed with pre-exposure to different pathogens.”

DNA methylation involves a reversible chemical change to the DNA strand and is an example of epigenetics. Epigenetics affect how our genes work, without changing the underlying sequence of our DNA. In the case of methylation, methyl groups are added to the DNA strand. The methyl groups typically block proteins that are needed for gene expression, thus turning the gene “off”.

Although these changes don’t affect the underlying DNA sequence, epigenetic changes can still be transmitted from parent to child. In fact, these changes have been proposed as an explanation for the increased risk of certain metabolic diseases in children born to women who experienced poor nutrition in pregnancy. Notably, studies of people affected by the Dutch famine at the end of World War II greatly advanced this aspect of our understanding of epigenetics and its role in health[5,6].

No evidence that the level of residual DNA in vaccines poses a health risk

Even if residual DNA were to make it into our cells, there’s no evidence indicating this would integrate into our genes. As the Vaccine Education Center of the Children’s Hospital of Philadelphia explained here, for DNA to integrate into our genome, the DNA would not only have to enter the nucleus, the enzyme called integrase is also needed, which isn’t present.

There are also other obstacles. Marc Veldhoen, an immunologist and professor at the University of Lisbon, took to X/Twitter to explain why DNA in COVID-19 mRNA vaccines doesn’t trigger concerns about health.

He highlighted the fact that there are already a number of vaccines in use that contain DNA, such as the COVID-19 adenovirus vector vaccines, as well as the chickenpox vaccine (the virus for chickenpox is a DNA virus). There’s no evidence that these vaccines are associated with a greater risk of developing cancer.

He added:

“Like DNA or RNA vaccines, vaccines using attenuated or killed pathogens work from a similar principle. The DNA/RNA gets into your cells, and protein from the pathogen is made. Important(sic), DNA/RNA vaccines cannot amplify nor do they generate infectious material.”

In all these cases, DNA would make it into our cells. However, our cells have multiple ways to detect foreign DNA and destroy it, since our immune system sees foreign DNA as a sign of infection[7-9]. This would eventually lead the affected cells to die by programmed cell death (apoptosis) and the removal of the cell, proteins, DNA, and RNA left behind.

“So no, even with scare stories about SV40 enhancers, the DNA or RNA does not get into the nuclei, it certainly does not integrate, the cell dies. It detects DNA or RNA, and it dies. It makes foreign protein, and it dies. i.e.; no matter what, the cell dies,” Veldhoen concluded.

It is also worth keeping in mind that if exposure to DNA alone were sufficient to produce DNA changes, then gene therapy (altering people’s genes to cure a disease) would be a lot easier to accomplish than it actually is.



Published on: 17 Nov 2023 | Editor:

Health Feedback is a non-partisan, non-profit organization dedicated to science education. Our reviews are crowdsourced directly from a community of scientists with relevant expertise. We strive to explain whether and why information is or is not consistent with the science and to help readers know which news to trust.
Please get in touch if you have any comment or think there is an important claim or article that would need to be reviewed.