it was basic logic accessible to anyone that washing hands doesn't matter - it was, after all, just dirt and blood. it couldn't be proven that there was anything bad in dirt and blood.

So you think that Nature as a journal saying previous covid infection gives antibodies like the vaccines, is comparable to how primitive medical science once didn’t know you had to wash your hands before surgery?

yes, in that common sense is volatile and using basic logic in presence of unknown unknowns is a risky proposition. i don't particularly care about the paper because it doesn't apply to the variant which hasn't evolved yet.