In Lab Study, Pfizer Vaccine Showed Potential to Alter DNA in Human Liver Cells, but Scientists Caution More Research Needed

Story at-a-glance

  • There have been large numbers of adverse events associated with the Pfizer-BioNTech mRNA vaccine, or BNT162b2.
  • RNA vaccines are appealing because they can be developed quickly compared to vaccines that use other technologies.
  • However, with this novel technology, we don’t know all the potential risks, such as the possibility of genetic modification of the genomic DNA.
  • This study from Lund University showed BNT162b2 enters human liver cells in vitro and is reverse-transcribed into DNA within six hours.
  • The study did not assess whether the DNA reverse-transcribed from BNT162b2 is integrated into human genomic DNA.
  • The investigators recommended further research to determine if the reverse-transcribed DNA derived from BTN162b2 can integrate into human genomic DNA, because this could cause adverse events.

Researchers from Lund University in Sweden published a study showing the mRNA from the Pfizer-BioNTech COVID-19 vaccine (BNT162b2) can be reverse-transcribed into DNA in human liver cells in vitro (outside the living body).

Transcription is the normal process by which mammalian cells use DNA to synthesize a molecule of RNA, before translating the RNA into protein. Reverse-transcription is when the cells use RNA molecules to synthesize DNA.

Some articles and social media posts interpreted the Lund study to mean that if the BNT162b2-derived DNA is reverse-transcribed, it can then integrate into the genomic DNA within the cell nucleus, and thus change human DNA.

However, this interpretation is incorrect. What the study actually showed is that mRNA from the Pfizer vaccine can be reverse-transcribed into DNA fragments within the cells of a human liver cell line in vitro.

In other words, the researchers witnessed the reverse-transcription process in a lab, outside the human body — they did not observe the reverse-transcription in a human who received the vaccine.

The authors concluded further studies are needed to investigate whether BNT162b2-derived DNA can integrate into human chromosomes.

The authors are right — scientists should conduct these studies.

Why? Because if vaccine-derived mRNA can be reverse-transcribed into DNA, and then integrate into the chromosomal DNA in a given cell, it’s possible this cell would be able to keep making the spike protein indefinitely. If that were to happen, and the spike protein continued to “present” on the cell’s surface, the immune system would target those cells for destruction, which could lead to organ damage.

Moreover, this DNA would be replicated each time the cell divides, giving rise to an entire cell line that is potentially capable of generating spike protein.

Another potential concern is this: If the BNT162b2-derived DNA can become integrated into human genomic DNA, this could cause genetic modification of the germline, meaning the DNA within egg or sperm cells. If this were to occur, the genetic modification could be inherited.

Pfizer’s preclinical data from animal studies showed that small amounts of BNT162b2 end up in the ovaries and testes after injection.

If BNT162b2 DNA became integrated into an important gene in an egg or sperm cell, and disrupted the expression of that gene, that could be catastrophic for the resulting embryo.

Worse, if the DNA coding the spike protein remained intact and expressed, that would likely be lethal to an embryo.

The BNT162b2-derived DNA could also become integrated into a non-coding region (a region of DNA that does not code for a protein), and not cause issues. The key is to determine if this is a possibility, and if it is, what is the risk?

Lund paper lists 12 papers on Pfizer vaccine adverse events

Multiple sources of data — including the Vaccine Adverse Event Reporting System (VAERS) database, data released by a German health insurance company, a recent survey conducted by Israel’s Ministry of Health, and the Pfizer phase 3 trial — indicate a high number of adverse events associated with Pfizer’s COVID vaccine.

The Lund paper lists 12 papers on adverse events.

court-ordered document released in November 2021 by the U.S. Food and Drug Administration (FDA) revealed 1,232 deaths occurred in recipients of Pfizer’s shot during the first three months of the vaccine’s rollout.

The 1,232 deaths were a subset of 42,086 case reports listing 158,893 adverse events during those three months.

In light of the clear evidence of harm and death associated with the rollout of BNT162b2, it is imperative to reassess claims made to the public by the FDA, the U.S. Centers for Disease Control and Prevention (CDC) and other health authorities that BNT162b2 is “safe and effective.”

The contribution of this paper from Lund University is preliminary work to investigate a possible mechanism for how adverse events associated with Pfizer’s vaccine could be occurring for extended periods after inoculation.

COVID-19 vaccine development: background

Before diving into the Lund paper itself, let’s look back at the race to develop COVID vaccines.

After the World Health Organization in March 2020 declared COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a global pandemic, the race was on to develop vaccines.

Health officials told the public vaccines were the only way to end the pandemic. A flurry of research on vaccines using a range of technologies ensued.

The established approaches were replication-defective recombinant adenoviral vector vaccines (pursued by Johnson & Johnson (Janssen), AstraZeneca, Sputnik V and CanSino), and inactivated virus vaccines (investigated by Sinopharm, Bharat Biotech and Sinovac).

Pfizer-BioNTech and Moderna chose to use a recent innovation: mRNA vaccines.

Viruses are fascinating beings at the threshold of what we consider living and non-living. They are submicroscopic, so tiny that we cannot see them with a microscope.

Viruses contain genetic material (DNA or RNA) inside a protein coat. They have no metabolism and can reproduce only by hijacking a host cell’s protein-synthesis and DNA-replication abilities.

Viruses appear completely inactive, tiny bits of protein with genetic material inside, floating passively around — until they encounter a potential host cell. Then the virus can infect the cell, hijack the cell’s machinery and make more copies of itself.

In the process, they may kill the host cell.

Humans are eukaryotes, meaning our cells contain a nucleus. Our cells are composed of the nucleus, the cytoplasm,= and a cell membrane. Our DNA lives within the nucleus.

The “Central Dogma” of genetics is that DNA gets transcribed into messenger RNA (mRNA), which is then translated into protein. Much of our bodies are made of protein, which is encoded by our DNA.

The job of the mRNA is to take the information from the DNA out of the nucleus and into the cytoplasm, where the cell’s ribosomes then turn that information into proteins.

When a virus infects a cell, it uses the cell’s transcription and translation abilities to replicate itself. The host cell acts like a diligent factory that churns out new viruses, composed of viral DNA or RNA, packaged in the viral protein coat.

The purpose of a vaccine is to try to teach the body’s immune system to recognize a pathogen and protect the body, without actually being infected with the pathogen.

With viruses, this is accomplished by exposing the cells to all or parts of the virus’ protein coat, and convincing the body’s immune system that this bit of protein is harmful and so warrants mounting an immune response and subsequent immunity.

mRNA-based vaccines are a recent innovation, thrust into the limelight during the pandemic. The first report on the successful use of mRNA to produce protein in animals was published in 1990, when mRNA was injected into mice and protein production was detected.

Dr. Robert Malone, now known as an outspoken critic of the Pfizer and Moderna COVID vaccines, was one of the authors of this seminal paper.

To make mRNA vaccine technology a viable option, researchers had to find a way to protect the mRNA from RNAse and deliver it into the cell. RNAse, found everywhere including inside and outside the human body, destroys RNA. Several vehicles for RNA were researched.

The authors of a November 2021 study, “BNT162b2 safety and efficacy,” published in the New England Journal of Medicine (NEJM), described BNT162b2 as lipid nanoparticle (LNP)-encapsulated, meaning the LNP capsule protects the RNA from RNAse.

The BNT162b2 RNA is nucleoside-modified RNA (modRNA) and encodes the full-length of SARS-CoV-2 spike protein.

The way the Pfizer vaccine works is a bit like the RNA-based SARS-CoV-2 virus itself. Unlike a virus, the RNA in an LNP-encapsulated vaccine is encapsulated in fat rather than in protein.

Once in the cell, in the case of BNT162b2, the vaccine produces only the spike protein, versus using the cells’ organelles to manufacture new whole viruses (composed of genetic material and protein coats) — the way a real virus would.

Thus, instead of exposing the host to the SARS-CoV-2’s entire protein coat, BNT162b2 exposes only the host to the spike protein.

One of the strengths of this novel approach is that vaccines can be developed relatively quickly because all that is needed to get started is the viral genetic sequence.

According to the authors of the NEJM study, the development of BNT162b2 began on Jan. 10, 2020, when the SARS-CoV-2 genetic sequence was released. Eleven months later, the FDA granted the vaccine Emergency Use Authorization.

Another advantage of mRNA vaccines, according to Pardi et al, 2018, is safety: “mRNA is a non-infectious, non-integrating platform, there is no potential risk of infection or insertional mutagenesis. Additionally, mRNA is degraded by normal cellular processes,” which means the molecule does not persist in the body.

However, human cells are capable of reverse-transcribing mRNA into DNA. This is the exception to the “Central Dogma” of genetics, which says information flows only one way in mammalian cells, from DNA to RNA to protein.

The Lund paper investigated whether BNT162b2 could be reverse-transcribed by human liver cells themselves, with their own native mechanism.

Why is the Lund study relevant?

The Lund researchers cited a 2021 study from the Massachusetts Institute of Technology (MIT) showing the RNA of the COVID-19 virus, SARS-CoV-2, can be reverse-transcribed and integrated into the genome (the DNA within the nucleus) of human cells.

The key finding of the MIT study is that the viral-derived DNA appeared to integrate into human DNA. The researchers hypothesized this could explain why some patients continued to test positive for COVID via PCR tests long after clearing the infection.

The Lund authors did not mention that another study did not find evidence that SARS-CoV-2-derived DNA can be integrated into the human genome.

In any case, Pfizer’s vaccine contains RNA that codes for part of SARS-CoV-2.  Therefore the Lund team investigated the possibility that BNT162b2 could also be reverse-transcribed in human cells.

The authors noted that Pfizer’s assessment report to the European Medical Association (EMA) did not include genotoxicity or carcinogenicity studies, nor information on whether BNT162b2 crosses the placenta.

The EMA report did show that over a 48-hour period, the distribution of the vaccine (the LNP and the RNA) was observed mainly in the liver, adrenal glands, spleen, ovaries and testes, with maximum concentrations in these tissues observed 8 to 48 hours after the injection.

The Lund researchers chose to study a human liver cell line, Huh7, because of the temporary effects on the liver and high concentration of BNT162b2 in the liver after injection, reported in Pfizer’s EMA assessment report.

They presented evidence that the RNA in BNT162b2 is able to enter the Huh7 cells in vitro. The key finding is that once in the liver cells, the BNT162b2 mRNA is reverse-transcribed into DNA within 6 hours after exposure to BNT162b2.

Unleashing novel technologies on the public can lead to unforeseen health consequences. The contribution of the Lund paper is toward one line of investigation into what could be causing the high rate of adverse events following the Pfizer jab.

According to the researchers:

“Our study shows that BNT162b2 can be reverse-transcribed to DNA in liver cell line Huh7, and this may give rise to the concern if BNT162b2-derived DNA may be integrated into the host genome and affect the integrity of genomic DNA, which may potentially mediate genotoxic side effects.”

Again, contrary to some articles and posts about the paper, the Lund paper does not show the DNA reverse transcribed from BNT162b2 can then integrate into the genomic DNA within the cell nucleus. Nor do the researchers claim this within their paper.

Rather, the authors stated:

“Further studies are needed to demonstrate the effect of BNT162b2 on genomic integrity, including whole-genome sequencing of cells exposed to BNT162b2, as well as tissues from human subjects who received BNT162b2 vaccination.”

In other words, the study itself does not show us a mechanism to explain why there are adverse events associated with BNT162b2. But the results do suggest the need to further investigate whether the vaccine-derived DNA integrates into the human genome.

If the BNT162b2-derived DNA does integrate into human genomic DNA, it could cause disruption of gene expression and hence adverse events.

If further research shows BNT162b2-derived DNA does not integrate into genomic DNA, then other potential mechanisms need to be investigated to determine what is causing the adverse events.