One thing I do try to do during a lot of cold and flu season is reduce exposure to crowded places as much as possible. It's not all avoidable, I know, but I'd wager airline cabins are breeding grounds for a variety of ailments. It's a lot easier in retirement to avoid crowded stores especially around the Holidays and weekends when every place seems busy. I'm not obsessive about it but am onto the hand washing routine fairly good after being out. Seems like fairly simple things to try to beat the odds.