In my experience not. Not that I have much trouble with ich to begin with (though I avoid tangs like the plague).
On July 3rd I rescued two 3 inch blue-belly regals from starvation at the store. I took the chance since they were only $40 ea.
I gave them a prophylactic formalin bath and then put them into a newly set up 42 gallon tank full with live rock - it's quite literally a rock pile with lots of cracks and crevices. I feel that is important to make them feel secure.
I started feeding brine shrimp, Mysis and clams on the half-shell. I also gave them live tigger pods.
They started picking pods right the same day. The next day they went after the clams and also took some brine shrimp. After a week both would eat like pigs, though only the skinnier and submissive one would go for Mysis.
After a few days I added my (well quarantined) marine bettas to the tank to help clean up what the regals wouldn't eat.
After two weeks they had already regained a lot of weight.
Though with the recovery they also started to squabble a bit. Usually the dominant one would get angry when I would feed Mysis he wouldn't take but the submissive one would gulp down like crazy.
But by now both are eating Mysis (in my experience food envy helps to convince picky eaters to take food they at first don't like).
They are no longer skinny in the back and I think in a week or two they should be back to a normal healthy weight. The chasing has also become less and when I put food into the tank they feed next to each other.
Only taking pictures of them is next o impossible as they hardly ever stand still long enough. I gonna have take the after pictures when I take the tank apart in a month or two. At that point they may go into my new 100 gallon tank.
Besides a little bit of lymphocystis they didn't show any signs of infections and I really don't expect anything to show up later.