I used to automatically get a cold or respiratory infection after flying, but they’re doing a much better job on air scrubbing now and it’s been about four or five years since that has been a problem. But I only fly the major US airlines, mostly Delta, which does an excellent job.
The thing I think is most like to be a problem is contact with surfaces, so just bring some wipes and wipe off your tray table and arm rests, as well as any lavatory surfaces...and then give your self a hand-sanitizer treatment. I have seen a lot of people doing this for years, actually, and it’s a good idea. That said, most viruses die pretty quickly away from their host. But there’s a lot of other things out there, such as e-coli, that you can get from touching something. And never touch your face! LOL!
Yeah, as I said, I just have no need for having to fly.
But when I have, the thing that got we was the stopped-up ears. Had people give me their hints to try to make them pop, but nuthin worked, takes about a week to go away on it’s own.
Forget viruses - I hated the plugged up ears. (Also, I’m not in love with heights, but that’s a different issue, heh)