Also the breathing thing: as soon as you get symptoms (if not before) you should spray up your nose and throat with 0.1% hydrogen peroxide solution. So, if you buy 3% solution, you must dilute it by 30 times.

I've been doing a daily sinus rinse and have so far avoided the virus despite multiple exposures. I usually just do the saline packet, but if I know I've been around a big group, I'll add 5-6 drops of H202.