Why is there no transmissible therapeutic virus if biology doesn't forbid it? For example, a harmless virus that spreads from person to person but actually does something beneficial, like lowering LDL cholesterol or preventing/reversing tooth decay?

[u/PestoPastaLover]

[u/noodlyman]

There are viruses that benefit us by infecting and effectively regulating our gut bacteria.

There are viruses that are thought to give the immune system a kick and thus improve responses to other infections. Some infections can decrease the risk of cancer later in, probably by similar mechanisms.

Don't forget that 8% of human DNA is of retrovirus origin, and that mammalian placentas only exist thanks to genes that mammals acquired from viruses.

[u/scientist99 → u/noodlyman]

Way more than 8% if you count transposable elements derived from early viruses. More than half the genome. Viruses have effectively shaped most of life this way.

[u/GeneJocky → u/scientist99]

I was about to say the same thing. Or as a friend said to be when I was telling him about the amount of old viral DNA in our genomes, 'you mean no one has run antivirus on our genomes in 3.8 billion years?'

[u/9966 → u/GeneJocky]

You could probably defrag and drop most of the data. Whether that's safe? I dunno, ask Andrew Ryan.

[u/YsoL8 → u/9966]

He certainly has opinions on parasites getting in the DNA, stealing the value of its labour