DNA contamination with residual bacterial plasmids and truncated mRNA from the manufacturing process


The more I hear about mRNA vaccines, the more pleased I am that I had only the British AstraZeneca shot, which was a more conventional product. I deliberately chose it because I thought it would be safer. Sadly, it was never approved for use in the USA. I guess I should mention that I had zero after effects from my two injections: Not even a sore arm

We highlight the inherent safety issues associated with a lax regulatory framework for approval of the COVID-19 mRNA vaccines. In this article, we consider how lax regulation is related to DNA and RNA contamination issues.

Summary of Key Facts

Concerns have been raised about DNA contamination in the mRNA COVID-19 vaccines. The specific concern is the presence of higher-than-expected residual DNA plasmids used in the original mRNA production. Independent investigations suggest that the Pfizer mRNA vaccine may have high levels of DNA contamination, potentially exceeding regulatory limits.

There are theoretical risks associated with plasmid DNA expression and migration to the gut, which could affect human health and the microbiome. Concerns have also been raised about the quality control and manufacturing oversight of mRNA vaccines.

The European Medicines Agency (EMA), Europe's drug regulatory authority, noted the presence of truncated and modified RNA as impurities in the mRNA COVID-19 vaccines, raising the need for oversight.

Related to the manufacturing process, a Danish study compared the rate of adverse events to the batch size (number of doses in a batch) and found a correlation.

The Advisory Committee on Immunization Practices met last week to recommend the updated COVID-19 vaccine. However, the manufacturers presented little data from testing in humans. Moderna was the only manufacturer to present safety and antibody response data from experience with 101 individuals. Pfizer presented antibody response data from 20 mice and is currently collecting data from 400 individuals in clinical testing. No data on manufacturing oversight was presented during the meeting.

As part of the safety evaluation of drug approval, the CMC (chemistry, manufacturing, and controls) process becomes critical in identifying and eliminating impurities. It sets strict standards and product specifications to maintain the purity of each batch. Compliance with these standards is essential for obtaining approval from global health authorities.

Imagine you're a coffee drinker, and you decide to buy a bag of premium, freshly ground coffee beans from your favorite store. You expect that each bag contains pure, high-quality coffee grounds to brew that perfect cup of coffee. However, when you open the bag, you discover that it isn't just coffee grounds; it also contains a mixture of sand and other foreign particles. This unexpected impurity completely ruins your experience.

Just as you rely on the purity of your coffee grounds for a great cup of coffee, the pharmaceutical industry, including vaccine production, has regulations in place to ensure good manufacturing practices. Patients and consumers expect that these guidelines mean that drug or vaccine formulations are free from unwanted substances, ensuring their safety and effectiveness.

Controlling impurities in traditional chemical products is a well-established practice, but for biological products such as mRNA-based vaccines, managing impurities presents unique challenges.

mRNA Products Contain 'Gene Factories'

Double-stranded DNA (dsDNA) is used to make the mRNA contained in the COVID-19 vaccines. Tiny dsDNA plasmids are small engineered gene factories (Figure 1). These factories produce the mRNA strands contained in the LNPs. A plasmid appears like a tiny micro-bracelet with different segments representing different pieces of genes.

Regulatory agencies like EMA—Europe's drug regulatory authority—set limits for the number of plasmids in the final lots distributed for injection. New questions have been raised about how much contamination there is, and whether the FDA is monitoring this. It is also unclear whether the plasmids can merge with human genes within the cell or travel to the gut.

The EMA standard for DNA contamination of vials is 0.33 percent (330 pg/mg), or roughly one DNA molecule for every 3,000 mRNA molecules. Although the Moderna mRNA-1273 vaccine meets this standard, the actual volume may be higher due to poor quality control. The DNA must be removed from the final product before distribution, but some residual amount is expected to remain.

Unanswered questions include: How much DNA is in the vials? Is it over the limit? Is the FDA tracking this? And what are the implications, if any, with regard to persistence in the recipient?

There are at least two independent groups of investigators who have conducted lab tests and confirmed the mRNA vaccine of Pfizer has been contaminated by DNA.

One team of scientists, led by microbiologist Kevin McKernan, published a preprint paper showing that the Pfizer/BioNTech BNT162b2 vaccine has DNA “orders of magnitude higher than the EMA’s limit.” His paper has not yet been peer-reviewed. The batches examined, provided by an anonymous source, were unopened, expired vials that were not delivered on dry ice. If these data hold, the actual amount of plasmids was 18 to 70 times higher than the EMA limit. (Table 3, page 12.)
Obviously, future investigations should attempt to establish contamination levels using unexpired doses with an intact cold chain.

Professor Phillip Buckhaults, who holds a doctorate in biochemistry and molecular biology and is considered an expert in cancer genomics research at the University of South Carolina, performed an independent analysis for the presence of DNA in Pfizer batches.

Professor Buckhaults in testimony stated the following:
"The Pfizer vaccine is contaminated with plasmid DNA. It's not just mRNA. It's got bits of DNA in it. This DNA is the DNA vector that was used as the template for the in vitro transcription reaction when they made the mRNA. I know this is true because I sequenced it in my own lab."

We will continue to follow this line of research.

Theoretical Risk of Plasmid DNA Contamination

While having some DNA in a sample is unavoidable and deemed acceptable, some have raised questions about the possibility for genomic integration of the DNA. Our cells use DNA in the nucleus to make protein, so if the plasmid DNA gets into the nucleus, there is a theoretical risk that it can get transcribed and make a protein.

About 5 to 10 percent of our human genome contains ancient retroviral DNA. However, this DNA is mutated to a point that is no longer harmful. Any further research on this topic will therefore need to establish not just the presence of DNA plasmid integration, but also its biological activity.
Professor Buckhaults further commented in his testimony:

"I am kind of alarmed about the possible consequences of this—both in terms of human health and biology—but you should be alarmed about the regulatory process that allowed it to get there."

Concerns About DNA Migration to the Gut

Related to the DNA contamination is the concern about residual expression vectors, or plasmids, in the vials. To make a billion doses of mRNA vaccine, more than a kilogram of DNA is required. Plasmids help produce the DNA by splicing in the desired sequence into a bacterial plasmid (Figure 1).

Then workhorse bacteria, often E. coli, help spin out the DNA for production. These bacteria have an extra burden: They must replicate not only their own genome but also the plasmid DNA inserted within their genome. This takes slightly more time, so the bacteria without the additional DNA will eventually outcompete those with the DNA.

To solve this problem, scientists also splice in an antibiotic resistance gene. The entire pool of bacteria is then treated with an antibiotic to kill the faster-replicating bacteria without the conferred antibiotic resistance. This selective elimination allows the plasmid-carrying antibiotic-resistant bacteria to continue growing. In other words, this antibiotic resistance gene confers an advantage that drives selection pressure to favor the bacteria producing the desired DNA.

However, some scientists are concerned that exceeding EMA standards for DNA plasmid contamination could affect an already growing antibiotic resistance problem. This would be a potential concern only if plasmids containing the antibiotic resistance gene migrate to the gut, integrate with bacterial targets in the gut flora, and disrupt the microbiome of the gut accordingly. Diseases, including obesity, diabetes, cardiovascular disorders, cancer, hypertension, and irritable bowel syndrome have been loosely linked with disturbances of the gut microbiome.

Truncated mRNA Contamination

Nucleic acid contamination with truncated, or shortened, mRNA fragments is something that EMA has been following since February 2021. On page 35 of the EMA assessment report (pdf) on the BNT162b2 mRNA vaccine reviewed in Part 1, the EMA states, "Truncated and modified RNA are present as impurities." The agency noted that the impurities were found at different levels during production. For instance, levels may be higher in smaller test batches than in larger commercial batches.

In fact, Danish scientists, Max Schmeling, Vibeke Manniche, and Peter Riis Hansen linked adverse events with vaccination records and found that smaller batches of the BNT162b2 mRNA vaccine may have a higher rate of adverse events (AEs). While this finding is intriguing, the authors call for more research to see if this is a consistent pattern. We reviewed the raw data provided by the authors and agree that a clustering of AEs seems to be found with batches having fewer than 100,000 doses.

It has already been demonstrated in vitro in a laboratory experiment that mRNA can be reverse-transcribed to DNA within six hours. A remaining question is whether this can happen in a live organism. Thus far, there is no evidence that a reverse-transcribed DNA product can merge with a human cell’s genome. Claims about integration are solely speculative and based upon an evolutionary precedent for such a process.

The EMA asked for additional testing but allowed distribution to go forward. The scientists believed these fragments were unlikely to be intact mRNA fragments. An intact mRNA fragment needs to have a cap and a tail. The cap and tail are needed to tell the cell when to start and stop producing the spike protein.

Nevertheless, the EMA requested additional reports. The agency was concerned that an autoimmune reaction could be triggered if fragments' potentially encoded proteins resemble human proteins. In other words, if the fragments "mimic" human proteins, antibodies could be developed against our own bodies.

"Any homology between translated proteins (other than the intended spike protein) and human proteins that may, due to molecular mimicry, potentially cause an autoimmune process should be evaluated. Due date: July 2021. Interim reports: March 2021, and on a monthly basis," the EMA stated.

It is clear that the mass production of mRNA at an industrial scale carries potential risks. This issue has been raised recently by other researchers pointing out the role of manufacturing quality control. For instance, The Epoch Times has previously investigated the link between quality issues and clotting risk (Part 1, Part 2, and Part 4).

This issue of contamination by DNA and mRNA fragments should also be explored further to understand whether certain lots were affected more than others. We also need to know whether DNA contamination is linked to adverse events. The EMA should strictly follow its monitoring standards.

The issue of having any DNA contamination is biologically unavoidable given that the mRNA is transcribed from DNA vectors. The potential issue here is the unusually high level of DNA contamination involved in the mRNA vaccines.

However, pivoting these RNA therapeutics to a vaccine platform in the context of a lagging regulatory framework has left us with many unanswered questions. Public health officials, nevertheless, were adamant that this new product should be deployed in a one-size-fits-all manner ignoring differential COVID-19 risk profiles across a broad population. This, in turn, we believe, set the stage for policy overreach resulting in unethical and harmful mandates.

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