Pitting arguments by authority against one another, in most of the EU, vaccination is considered equivalent to documented proof of recovery from COVID within the past 6 months

Given the Dr Kheriaty was infected last year, wouldn't that mean that even by EU standards, he would be considered the same as a Covid-naive individual?

Yes. And honestly, he probably should be, using the precautionary principle? I don't think there's great data showing that people infected with the ancestral variant have good immunity to Delta. Certainly, a lot of people who'd had the ancestral variant were re-infected with Beta, when there were big outbreaks of that in South America.

Your common sense. No one can be an "expert" on Corona. They don't even know what it is! Certainly this was true by the first lockdown.

There is no such thing as common sense in immunology.

Claiming "common sense" is about as empirically useful and valid as claiming "street smarts".

No, thanks, I'll stick to the people that would rather peruse evidence and draw limited conclusions and admit that educated guesses are still far better than uneducated guesses.