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Residual DNA in COVID-19 mRNA vaccines is documented, isn’t associated with genome modification or cancer, contrary to claim by Robert Malone

Posted on:  2023-11-03

Key takeaway

Epidemiological data show that additional doses of COVID-19 vaccines (boosters) reduce the risk of getting the disease. Residual DNA in mRNA vaccines, small fragments broken down by enzymes, are leftovers from the vaccine manufacturing process. The quantity of residual DNA in the COVID-19 mRNA vaccines is within the acceptable range established by regulators, who were aware of residual DNA in the vaccines prior to authorization. There’s no scientific evidence suggesting that residual DNA poses a risk to health in the quantities present in COVID-19 mRNA vaccines.

Reviewed content


The more COVID-19 vaccines doses people receive, the higher the risk of getting COVID-19; vaccines contain DNA fragments that modify the genome and cause cancer

Source: The Charlie Kirk Show, Robert Malone, 2023-10-27

Verdict detail

Inadequate support: The claim that vaccinated people are more likely to get COVID-19 or aggressive cancers isn’t supported by evidence. In fact, epidemiological studies show that additional doses of vaccines reduce the risk of getting COVID-19. Moreover, there is no data indicating that residual DNA contained in COVID-19 vaccines can modify the human genome.
Factually inaccurate: Contrary to the claim, regulatory authorities were aware that vaccines could contain residual amounts of DNA. In fact, the amount of residual DNA is among the criteria assessed to ensure quality in the vaccine manufacturing process.

Full Claim

The more COVID-19 vaccines doses people receive, the higher the risk of getting COVID-19; unbeknownst to health agencies, mRNA vaccines contain DNA fragments that modify the human genome and cause cancer


On 27 October 2023, podcaster Charlie Kirk interviewed scientist Robert Malone about the question of residual DNA in COVID-19 mRNA vaccines. This interview was posted to various platforms, including Facebook and Rumble, receiving a total of more than 78,000 views. As previous Health Feedback reviews can attest to, both Kirk and Malone have a long history of propagating misinformation about COVID-19 vaccines.

Once again, Malone made several unsubstantiated claims about COVID-19 vaccine safety. This review will explain what those claims are and why they are unsubstantiated.

Claim 1 (Unsupported):

“The data that is coming from all over the world is that the multiply vaccinated or inoculated are the ones at highest risks of becoming diseased with SARS-CoV-2. It’s called ‘negative effectiveness’.”

Malone claimed that COVID-19 vaccines showed “negative effectiveness”. It means that getting the vaccine would increase the risk of getting the disease, whereas the goal of a vaccine is supposed to be the opposite.

Malone didn’t provide any evidence to support his claim. However, his mention of the “multiply vaccinated”, strongly hinted at a study by Cleveland Clinic researchers, which assessed the effectiveness of bivalent COVID-19 vaccines in healthcare zorkers[1]. One of the key observations of their study was that the number of vaccine doses received showed a positive association with the risk of COVID-19. This means that people who received more doses also had a great risk of COVID-19.

Because of this observation, the study formed the basis for misinformation, specifically the claim that getting vaccinated against COVID-19 actually increased a person’s risk of COVID-19. Health Feedback explained in a previous review that this claim is unsupported by scientific evidence.

The study’s lead author, infectious disease physician Nabin Shrestha, clarified in an email to Health Feedback that “association is not causation”, and that “Any claim that our study shows a causal relationship between getting more doses of the COVID-19 vaccine and higher risk of infection is false”.

Interpreting the study’s results requires taking into account a few of its limitations, as these could bias the results. It’s important to keep in mind that there are several variables that can modify one’s risk of infection; the number of vaccine doses a person received is only one of them.

One such variable is whether a person was previously infected. This is because a previous infection with SARS-CoV-2 provides some degree of immunity against reinfection, although this protection wanes over time. Therefore, whether participants had had a previous infection by SARS-CoV-2, and how long ago the infection took place, can influence the results of the study. In fact, this was discussed as one of the study’s potential limitations by the study’s authors in the Discussion section.

Another variable influencing a person’s risk of infection is their level of exposure to the virus. For example, frontline healthcare workers, such as physicians and nurses, are more likely to be exposed to the virus compared to those who don’t have patient-facing jobs, such as clerical staff. If people who receive more doses of the vaccine are also more likely to have patient-facing jobs—and therefore more often exposed to COVID-19—then the greater risk of COVID-19 seen in this group could be due to their greater exposure to the virus.

Consequently, the observed association between COVID-19 risk and the number of COVID-19 vaccine doses may simply reflect the fact that people at higher risk of COVID-19 due to their work are more likely to receive more vaccine doses. However, the study didn’t report whether those who received more doses were also more likely to hold patient-facing jobs. As such, this is one potential caveat in the study that we cannot rule out.

Contrary to Malone’s claim, real-world data actually confirm that getting more doses of a COVID-19 vaccine doesn’t increase the risk of getting the disease. Several studies reported a reduced risk of infection after a third dose compared to only two doses[2-4]. Additional doses were also associated with a reduced risk of severe disease and hospitalization[5,6].

Claim 2 (Unsupported and Inaccurate):

“These [vaccines] are delivering short fragments of DNA into your body and they will cause genetic changes and this may be one of the drivers behind the quote turbo cancers that we’re seeing arise.”

This is simply a repetition of a claim that circulated on the internet in 2023 after the release of two preprints reporting the presence of DNA in the Pfizer and Moderna COVID-19 mRNA vaccines.

Much has been made of these findings, with individuals like entrepreneur Steve Kirsch and outlets like The Epoch Times claiming that this DNA could alter people’s DNA and cause cancer. Health Feedback already discussed this claim in two previous reviews and concluded that it was unsubstantiated.

As we explained before, the vaccine manufacturing process involves the use of DNA. Briefly, a circular of DNA molecule called a plasmid carrying the genetic material to produce the SARS-CoV-2 spike protein, as well as other DNA sequences to improve efficiency, is introduced into the bacterium Escherichia coli. This plasmid is then replicated on a mass scale in the bacterium E. coli.

Next, the plasmid DNA is harvested from the bacteria and cut so that the segment containing the genetic material encoding the spike protein is isolated. This segment is then transcribed into mRNA and incorporated into the vaccine nanoparticles. The remaining DNA from the plasmid is digested by enzymes and broken into pieces. Thus, some amounts of DNA from the manufacturing process can remain in the final product, in the form of small fragments.

While there is residual DNA in the COVID-19 mRNA vaccines, Malone didn’t mention that the amount of DNA detected in the vaccine vials is well below the World Health Organization and U.S. Food and Drug Administration’s recommended limit of 10 ng DNA/dose . In fact, as a previous Health Feedback review noted, this was acknowledged by the authors of one of the preprints that Malone’s claim relies on.

Furthermore, there is no scientific evidence or plausible mechanism suggesting that these DNA fragments would alter our genome.

Among the DNA sequences identified, the authors reported the presence of DNA derived from the simian virus 40 (SV40) in the Pfizer vaccine (but not Moderna). The SV40 virus has been found to cause cancer in some animals like hamsters[7,8] and had been the cause of a health scare when it was found to contaminate polio vaccine used in the fifties and sixties.

However, there is no evidence that SV40 increases the risk of cancer in humans, as we explained in one previous review. Furthermore, vaccine vials only contain fragments of one segment of the SV40 DNA, not the virus itself nor its full genetic sequence, which makes the risk of an interaction with our genome even less plausible.

As Health Canada, the Canadian health agency, said in a statement to Health Feedback:

“The SV40 promoter enhancer sequence was found to be a residual DNA fragment in Pfizer-BioNTech COVID-19 vaccine. 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.”

Health Canada also told to The Epoch Times that:

“The DNA plasmid used for the Pfizer vaccine production is linearised, degraded, and reduced in quantity through additional steps. There is no peer-reviewed evidence that linearised or fragmented DNA is capable of translocating to the nucleus of cells”.

Furthermore, even if residual DNA were to make it into our cells, there’s also no evidence indicating this would lead to its integration into our DNA, causing mutations. Indeed, cells have mechanisms to recognize and target DNA entering the cells, as the presence of foreign DNA is interpreted as a signal of infection.

In fact, 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). Yet they aren’t associated with genome modification or cancer.

It is also inaccurate to claim that regulators were unaware of residual DNA in the vaccines. Monitoring the presence of residual DNA in biological products and assessing its potential health concerns isn’t new to regulatory agencies[9].

A document submitted by BioNTech to the European Medicines Agency, dated 19 February 2021, indicated that residual DNA was among the impurities that were quantified during the process of developing and validating the vaccine manufacturing process(“Process- and product-related impurities including host cell genomic DNA, RNA, proteins, endotoxins, bioburden and plasmid isoforms, for the plasmid DNA, are routinely quantified”).

Emails released by The Epoch Times also show that Health Canada was “aware of the presence of residual plasmid DNA as a process-related impurity during review and prior to the authorisation of the mRNA COVID-19 vaccines”.

Finally, Malone also mentioned “turbo cancers”, that we are allegedly “seeing arise”. While there is no official definition of what “turbo cancer” is, the name implies that this is a rapidly progressing, aggressive form of cancer.

Yet, the National Cancer Institute explained that “There is no evidence that COVID-19 vaccines cause cancer, lead to recurrence, or lead to disease progression”. In fact, cases of alleged “turbo cancers” are merely a narrative built on anecdotal accounts and have no basis in fact.


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