DNA Contamination in Pfizer COVID Vaccine Exceeded 500 Times Allowable Levels, Study Finds

A new peer-reviewed study raises concerns over inadequate testing methods for measuring DNA impurities in…

Children's Health Defense

A new peer-reviewed study raises concerns about the methods used to test for potential DNA impurities in the Comirnaty COVID-19 mRNA vaccine produced by Pfizer and BioNTech.

In the study published this month in Methods and Protocols, German researchers Brigitte König and Jürgen O. Kirchner questioned the reliability of the quantitative PCR (qPCR) technique Pfizer-BioNTech used to measure DNA contamination in the vaccine’s active substance.

The researchers experimented with dissolving Comirnaty‘s lipid nanoparticles. They found DNA impurity levels ranging from 360 to 534 times higher than the 10 ng (nanogram) per dose limit set by regulators globally.

The researchers proposed that fluorescence spectroscopy methods could more reliably quantify the total levels of DNA contamination present in the final, ready-to-use vaccine product.

Kevin McKernan, chief scientific officer and founder of Medicinal Genomics, told The Defender that while the authors raised some crucial points regarding DNA contamination in COVID-19 mRNA vaccines, fluorometric dyes can be unreliable, leading to inflated readings.

‘A massive under-detection of DNA impurities’

Manufacturers like Pfizer-BioNTech use DNA contamination testing that relies on a qPCR method applied to the vaccine’s active substance before it is combined with lipid nanoparticles.

König and Kirchner pointed out that the qPCR test looks only for a tiny 69-base-pair segment of the original 7,824-base-pair DNA template used to produce the mRNA vaccine.

This means Pfizer checks less than 1% of the original template. The other 99% goes unanalyzed, resulting in “a massive under-detection of DNA impurities,” they stated.

The researchers also argued that this small segment may get destroyed at different rates than the rest of the DNA template fragments during the enzyme digestion process, further confounding accurate measurements.

Another complicating factor is that the qPCR target sequence overlaps with a section of DNA called the T7 promoter used to produce the mRNA. Cellular machinery or byproducts could bind to this promoter region, blocking it from being detected by the qPCR test.

David Speicher, Ph.D., co-author with McKernan and others of a preprint study on DNA fragments in Moderna’s and Pfizer’s COVID-19 vaccines, expressed similar concerns.

PCR can quantify only a particular DNA/RNA sequence targeted by the primers used, he told The Defender. If there are any breaks or mutations in that target sequence, the “DNA will not amplify and the loads will be under-reported.”

“There is also an assumption that the DNA in the vaccine is only from the plasmid and not bacterial or any other source,” Speicher said.

McKernan pointed out another problem: Regulators allow Pfizer to use qPCR to measure the DNA and fluorometry to measure the RNA.

“The regulations from the EMA [European Medicines Agency] are a ratiometric measurement of RNA:DNA,” he said. “The ratios should not be measured with inches for RNA and meters for DNA.”

He said Pfizer should measure both the RNA and the DNA using fluorometry or qPCR. “When they allow them to mix and match tools like this, they enable overt deception.”

McKernan also shared a portion of Moderna’s patent application acknowledging that qPCR is inadequate for measuring small DNA fragments…