> what do we know?

I’ll reply again: a lot. You can’t possibly expect me to summarise the vast, complex state of the art knowledge of RNA biology for a lay person here — it literally fills books. At the very least ask more specific questions, I’ll be happy to answer them, if I can.

> You clearly know nothing about the long term effects

Wrong. I’m no expert on all aspects of RNA vaccines, but I am an expert on RNA biology. What I do know allows me to conclusively exclude the possibility of the RNA in vaccines incorporating into the host genome (because that notion is simply not coherent). I’m not parroting any line here.

I didn't ask for a summary of RNA biology. I asked what we do we know about the long term effects of RNA vaccines? Preferably in humans. But as they the vaccines are new and haven't been authorized for humans I am skeptical that we can say anything conclusive. So far you haven't named one thing that we know. "Lots" isn't an answer.

> What I do know allows me to conclusively exclude the possibility of the RNA in vaccines incorporating into the host genome (because that notion is simply not coherent).

You are just using a strawman argument that some conspiracy theorists have come up with. I never suggested that would be the case.

> I asked what we do we know about the long term effects of RNA vaccines?

But that’s a completely open-ended question that really can’t be answered without referring to a primer of the underlying biology. I really don’t understand what you expect me to do here. It seems like you’re asking me to prove a negative and don’t tell me which negative to prove.

> … I am skeptical that we can say anything conclusive.

As I said we can say some things. And, contrary to your claim that I haven’t yet “named one thing that we know”, I’ve actually given a very concrete example: we can completely exclude the (often-cited, but completely unscientific) risk of viral RNA incorporating into the genome. This isn’t a straw man, it’s a frequent claim by opponents of the COVID-19 RNA vaccines. In fact, as far as I can tell this is by far the most prominent claim.

In the same vein, one can of course make long lists of potential long-term risks (cancer, Alzheimer’s, diabetes) — but unless these are plausible, this is unproductive. For most of these, there’s simply no biological connection at all. Demanding that all such far-fetched risks be rigorously excluded is unreasonable. By the same logic you could never cross the street because you can’t rigorously exclude the possibility of getting hit by a car, or a meteor. Rational risk assessment is always tempered by likelihood estimates.

The most likely, rational, long-term side effect of RNA vaccines was hypothesised to be a severe immune reaction, which might lead to the development of an autoimmune response. However, if that was the case, we would see the same effect in long-term animal trials, and we would see the start of this effect even short-term in human trials. But by now we have evidence against both of these: long-term animal testing shows no indication of an autoimmune response, and human trials don’t show any short-term ramping up of such a response.

So the most likely, hypothesised possible long-term effect is contradicted by existing evidence. Which goes back to my point: we do know some things.

Do I claim that the vaccine is risk-free? No. For conventional vaccines we have decades of data showing their safety. The evidence for brand new mechanisms obviously isn’t on the same level, and we can’t categorically exclude unknown interactions. But it’s really hard to communicate the magnitude of this risk, except to say that it’s really very small — because we can exclude plausible risks.