@johnpowell bring a face mask. When I flew to Japan the airline have everyone a face mask citing it was good to keep your nose and throat moist while sleeping, but my guess is it was a germ thing too knowing the Japanese. I used it without qualm. Many people on the flight did, some didn’t.
If you look at how many flights are in the air during the day the spread of disease is actually fairly low considering.
I’m a bit of a germaphobe also. I fly probably 4 round trips a year and sometimes am on trains longish distances, and can’t remember getting sick immediately after traveling in many years. I can only think of one cold about 10 years ago, and I can’t be sure I caught it on the plane. I often wind up flying during the height of flu and cold season.
I am cautious. I rarely read any of the magazines on board and if I do touch things I try my best not to touch my face and I wash my hands once I deplane.