Google long covid ncbi for a long list of papers. I don’t know what you mean with your no true Scotsman fallacy, there’s definitely something and quite a lot of research establishing what.
Where did you get your information?
Where did you get your information?
I'd suggest just sharing a good paper. Asking somebody where they got their information that something doesn't exist is pointless. You could say the same thing to somebody who doesn't believe unicorns exist; better to just show them a unicorn.