Welcome to the regionals.

Dehydration and fatigue impair your immune system, so hydrate. If you stay up all night drinking and then go fly, double whammy.

But you don't get sick from getting sneezed on, you get it from touching things and then touching your face. You can wipe all the surfaces you want, but the best defense is washing your hands constantly (gel works too), and you need to learn to be totally OCD about NOT touching your face when you're at work. If you really must, wash your hands thoroughly with soap and hot water first. Good habit, it helps in hotel rooms (the guy who checked out a few hours ago was smearing his bug-infested snot all over everything), and other public spaces even when you're not working.

Oh, and get the flu shot. If you're one of those people who doesn't get the flu very often, it will be REALLY bad when you do get it about once a decade. Inevitable in aviation.