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UPDATE:

Adding additional information after digging around.

First, I am not a medical professional.

I found this article studying the rates of DNA integration via adenovirus vectors in mice, specifically measuring for rates of integration in their liver cells. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2937808/

From Table 2, they plainly state that they observed integration of certain genome sequences as a result of administering the adenovirus. In their discussion they also state that further possible side-effects of integration need to be directly studied.

In the list of articles that cite the above source, I found a journal discussing the J&J vaccine for Covid-19: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8006140/

In it they state the following: "There are concerns about the possibility of DNA integration from the modified adenoviral vaccine, but this has not been reported to date"

They then cite the above article as their source for this statement. However, it seems completely incongruent with respect to what I understand about the first article.

If I understand the first article correctly, the blanket statement in the second article (as a defense for the safety of the J&J vaccine) seems greatly concerning. Any insight would be very welcome.

ORIGINAL:

Exactly the same question posed here, except with reference to the new Johnson and Johnson viral vector vaccine rather than mRNA.

Why is the new mRNA vaccine unable to modify human DNA?

I was able to find a great video source on the RNA vaccines: https://www.youtube.com/watch?v=eK0C5tFHze8

But haven't seen an equivalent for the Johnson and Johnson adenovirus vaccine.

The above quoted MedicalScience.SE contains an answer using this as a reference: https://www.frontiersin.org/articles/10.3389/fimmu.2018.01963/full

This resource was published late 2018 and specifically contains the following quote:

Especially in the context of this long-term persistence, the presence of foreign genetic information in the nucleus of transfected cells poses the additional risk of genomic integration into the host's chromosomes and the resulting threat of mutagenesis and oncogenesis.

Has there been any additional research on this topic when evaluating the safety of the new J&J vaccine, as well as the oft-referenced Ebola vaccine (as a proxy for the safety of this method) that uses a similar technology?

  1. TL;DR I'm looking for an explanation for why or how the J&J vaccine method cannot modify target cell DNA
  2. If it can modify target cell DNA, have the above issues posed in the 2018 review been addressed in the latest safety trials?
  3. If yes to the second question, are we certain that the side-effects cannot manifest in a longer timeframe? If not, how certain can we be?
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    That paper mentions "poses the additional risk" while citing a paper that states adenovirus vectors are episomal (do not integrate). They do not provide evidence supporting the existence of that risk. In fact, poor integration and transient expression have been seen as problems for adenoviral vectors in other contexts, requiring alternative strategies for gene therapy. For side effects in your point (3), you'd see it in the trials if it happens. – Bryan Krause Mar 1 at 17:51
  • @BryanKrause thank you for your response. I updated my original question with some more sources. Any insight you have on them would be greatly appreciated! – dant Apr 13 at 2:52

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