A new study published in Methods and Protocols raises concerns about the methods used to test for DNA impurities in the Comirnaty COVID-19 mRNA vaccine produced by Pfizer and BioNTech.
The study, conducted by German researchers Brigitte König and Jürgen O. Kirchner, questions the reliability of the quantitative PCR (qPCR) technique used by Pfizer-BioNTech to measure DNA contamination in the vaccine's active substance.
The researchers found that DNA impurity levels in the vaccine were significantly higher than the limit set by regulators. They proposed using fluorescence spectroscopy methods to more accurately quantify DNA contamination in the vaccine.
Kevin McKernan, chief scientific officer and founder of Medicinal Genomics, agrees with the concerns raised by the study but cautions that fluorometric dyes can be unreliable and lead to inflated readings. He suggests that the researchers should perform an RNase control to address this concern.
Despite potential limitations, the researchers argue that current regulations governing DNA contamination in vaccines are inadequate and call for a reevaluation of testing protocols.
The study also highlights potential risks associated with DNA contamination, such as insertional mutagenesis and the presence of cancer-promoting genes. McKernan emphasizes that DNA contamination regulations are unfit for purpose and questions why regulators are not sequencing the vaccines to know the precise sequence and frequency of DNA and RNA molecules.
