If you're not afraid of OTC medicine try Zicam when you fly / travel even just to ward off illnesses. They make a nasal moisturizer and a nasal cold / flu spray. Supposedly it mimics the nasal cell and allows it to bind and plug the virus from attaching and stopping it from replicating and entering your body. Majority of the folks who try it swear by it and I gotta say it does seem to work.

Next step up is an antibiotic prescribed by your doc to take while flying, which I don't advise but have used and it works for me so I do pack them but try not to use them. I don't advise it as you will build up a resistence to the antibiotic over time and it won't work anymore, resulting in that you'll probably get sicker later on in life. But if you get sick and have to fly for your living and have no choice, well then you gotta do what you gotta do.

Stay warm, drink fluids, and pack a lot of hand sanitizers gel's or such....

Get better, stinks being ill during the holidays.