And the second worse thing is to expose it to completely novel viruses. How about we expose it to as many common viruses as we want, but try to prevent novel viruses from popping up?
It's not a dichotomy - removing animals from our diet does not leave a sterile environment for humans. Humans and their environment are plenty filthy on their own.
Then this is purely a vegan argument unrelated to the virus.
Again, not a dichotomy. Humans will remain exposed to pathogens even if we eliminate one source of new and dangerous ones.
Clearly this is bullshit since exposing it to a sufficient load of HIV fucks it up proper. So we have an existence proof of at least one thing worse than "ceasing to expose it to pathogens".