There has been so much talk recently regarding Flu Prevention (both swine and regular) with most if not all the emphasis on washing hands and getting your flu shots, but I'm still waiting for the "experts" to mention the importance of a healthy diet.
Our bodies have amazing potential to fight off colds and illnesses, but only if you do your job in supplying it with what it needs to maintain this healthy immune system. A healthy body has an impressive army of fighting cells just waiting to seek and destroy any intruders (bacteria, parasites, germs of any kind), if it's been properly equipped with the weapons it needs... vitamins, minerals, anti-oxidants, and other key nutrients, none of which you are getting from skipping breakfast (or picking up something at the coffee shop to munch on) having takeout for lunch and throwing some pre-made heavily processed meal in the oven or microwave for dinner.
If you're not eating a healthy diet consisting primarily of fresh (hopefully organic) produce and whole foods, supplementing your diet with key nutrients like vitamins C, B, D, etc (seeking the help of a health care professional to determine dosage of course), and avoiding those foods you are allergic to then all the hand soap/sanitizer and flu shots in the world can't save you. And I'm sure you have the medical bills and sick days to prove it...
A healthy you starts with a healthy diet, it's as simple as that!