A scientific study  just showed that the vaccine messenger RNA (Pfizer vaccine) in vitrobe transcribed backwards  into DNA in human cells in the absence of viruses. This also has the benefit of emphasizing the importance of co-evolution of genomes.
Some data on the fate of vaccine messenger RNA
No genotoxicity or carcinogenicity studies were provided in the Pfizer Vaccine Evaluation Report  and the possibility of an effect of the vaccine’s messenger RNA on human genomic DNA has been ruled out by health authorities: ” In order to integrate into our DNA, this RNA would have to be reverse transcribed in the form of DNA, which is next to impossible. » read in The world in December 2020 .
However, it is worth remembering that a May 2021 study showed that the RNA of the SARS-CoV-2 virus can be reverse-transcribed (in part) and integrated into the genome of human cells. . It is therefore legitimate to wonder whether the vaccine’s synthetic RNA can do the same.
In addition, the documents submitted for the application for conditional marketing authorization (MA) for the Pfizer vaccine demonstrate the fact that the vaccine’s messenger RNA (mRNA) is present in many cell types, including gametes. although in low doses, but the study proves that its migration is possible.
RNA viruses: a long coevolution with their hosts
Some RNA viruses, such as HIV (AIDS virus), have enzymes that can retro-transcribe RNA into DNA and integrate into the host’s DNA. They bring these enzymes with them in their luggage when they infect cells, these viruses are called retroviruses. These viruses, which are still in circulation, are said to be exogenous. This has been the case for millions of years: retroviruses insert their genetic material into the host’s DNA , until it represents an important part of its genome and these additions of viral origin become transmissible when they reach the gametes. Thus, the current human species has integrated in its genome DNA corresponding to ancient viruses, testifying to a reciprocal evolution between virus and human species.
However, in the genes that integrate these viruses into our DNA, we find those that allow the synthesis of enzymes for reverse transcription and integration into the host’s DNA.
The DNA sequences of retroviruses integrated into the human genome, called ” endogenous viruses however, are subject to mutations and gene rearrangements over generations. They can be distinguished from the original viral DNA to the point of inactivity. genetic remnants »,« fossils “. However, for a certain number of endogenous viruses, this is not the case, and the human cell then has the enzymes associated with the reverse transcription offered by these viruses. The oldest endogenous viruses would be ancestral 150 million years ago of today’s people occurred  ! They are part of mobile DNA elements called retrotransposons (which make up 42% of the genome in the human species ).
Granted, the coronavirus that causes Covid doesn’t have a retrotranscription enzyme, it’s not a retrovirus, but it infects cells and can take advantage of the retrotranscription enzymes of ancient retroviruses that are integrated into the human genome. This helps to understand the results of the 2021 study.
Synthetic vaccine RNA integrates into human cells
In pharmacokinetic data provided to the European Medicines Agency (EMA) by Pfizer, the body distribution of ” vaccination » injected was monitored in mice and rats by radiolabelling  and most tissues showed radioactivity after fifteen minutes. The injection site and the liver were the most radioactive. On the other hand, clinical trials of this vaccine in animals reported reversible effects on the liver, including enlargement and changes in liver enzymes. It was also shown that the empty lipid nanoparticles, which normally carry the vaccine mRNA, do not introduce so-called significant hepatic lesions, which precludes their intervention.
As a result, the 2022 study  proposed to study the effect of the mRNA vaccine (Pfizer) on a lineage of human liver cells in vitro and to determine whether vaccine mRNA can be reverse transcribed from endogenous viruses into DNA using reverse transcription enzymes.
The experiments performed first showed that a retro-transcriptase protein increased its rate in the nucleus after the cells were exposed to the vaccine, evidence that the gene that encodes it and that is present in the DNA of the nucleus has become active. The synthesis of this protein takes place in the cytoplasm and the protein then enters the cell nucleus, probably during cell division where the nuclear membrane is ruptured.
Then the study showed that thanks to this protein, the vaccine’s synthetic mRNA is retro-transcribed into DNA in the lineage of these liver cells. The DNA resulting from this retro-transcription is detectable in the cell cultures six hours after addition of the vaccine. This retro-transcription of the vaccine RNA was not apparent, as we recall that the RNA in question is partially synthetic.
These results raise the question of whether this vaccine RNA-derived DNA can integrate into the cell’s genome and compromise its integrity, which could cause genotoxic side effects.
The study does not answer this question. Only genome sequencing of cells in which vaccine-derived DNA has been detected life will provide the formal proof.
Therefore, more work needs to be done to show or not the activity of the vaccine at the genomic level in the cells and especially in the gametes where we know the mRNA of the vaccine is distributed. However, it is known that an enzymatic equipment, inherited from a long co-evolution with retroviruses, is present in human cells and allows integration of vaccine-derived DNA into the genome of somatic cells and possibly gametes. It is therefore not from the realm of the impossible that the RNA of the vaccine alters the genetic heritage of humans.
At the somatic level, given the genotoxic potential of these integrations, it is unfortunate that the studies were not conducted pre-vaccination, ie in phase III clinical studies as with any true vaccine.