In some cases, they can become incorporated into our DNA and even be recruited to form new genes:
Nat. Rev. Genet. 2012 Mar 16;13(4):283-96. doi: 10.1038/nrg3199.
Endogenous viruses: insights into viral evolution and impact on host biology
Well, now I remember being told something like, that cancer can be caused by a virus . . . maybe I should say, certain viruses.
After all, viruses are said to get into cells, in order to reproduce. So, they might do some part-time job of playing around with the host cell's DNA.
So, this could mean a virus can alter DNA. But does this happen due to the virus grabbing the DNA and remaking it . . . or indirectly by changing chemistry in the cell so certain chemicals get loose to damage the human's DNA - - and this possibly in some random way . . . something that would not make it very helpful for conspiracy people or medical well-meaning people?
So, yeah, some people, I see, might feed on something like this and decide there is a conspiracy to give people a virus which can change our DNA so we all are the way the conspirators want us to become. And/or, ones might think, a vaccine could be developed with whatever a virus would use to alter everyone's DNA.
That would take ones capable enough of developing the technology, plus having the control. Of course, what they develop for genetic therapy could be shanghaied.
There is only one catch to this. My DNA does not decide my identity in the sight of God, not what physical DNA produces. All my DNA has been able to do is effect physical characteristics . . . but not the spiritual character of my personality. And only Jesus can change our character in a really right way . . . and give us the personality transplant that we really need!
But abusers can at the most control people with fear, but they miss out on finding out how to love, by doing this. And likewise if anyone did do a mass-change of people's DNA, this would not change people to know how to love. Only God can do this.
An abuser or conspirator might succeed in fooling and controlling some number of people, but then all he or she has is foolish people . . . ones who can be so fooled. And he or she can never trust them, because he or she always will know how they can be fooled . . . maybe now by someone else. So, we need to love people, by helping them to become wise so they can't be fooled; because if we want to fool someone, we want the person to stay able to be fooled, and this is not loving the person.
So, in case ones are trying to control people or fool people, concerning the vaccines . . . this is costing them themselves, very dearly.
But fearing is not loving, too.
"There is no fear in love; but perfect love casts out fear, because fear involves torment." (in 1 John 4:18)
So, in case we let ourselves get infected with fear about all this, this is a problem, too. And fear can change our personality.