I read yesterday was the official start of this years flu season. My advice is to start taking Biotest Superfood. It has a ton of concentrated fruits and vegetables in it to aid in everything from recovery to keeping you healthy all winter long.
Remember when you go to the gum, the dumbbell you are about to use or the machine you are about to get into has likely just been used be a guy (every gum has one or two) by someone who hasn't bathed in a few days for whatever reason. That means trouble for you. You can get sick and be knocked on your ass for a while. Not good!
The one lasting point I am leaving you with, as you already know is if you can't work out, you can't grow and get bigger. I have lived on this stuff and I seldom if at all get sick because of it. Also drink a gallon of water every day.
I am only saying this because in years past I always got sick several times throughout the winter and it would piss me off. All my hard work and gains were reduced and I felt like shit about having to deal with it on my mind.
Hope this helps and good luck.