I used to get free flu shots at work (still do) but in the last few years have decided to go without and (knock wood) I've been fine. Ironically, I was still getting the flu shots so either (1) the flu shot doesn't work, at least for me or (2) it really does give you the flu!
Dr. Mercola suggests the following:
There are many other, far more effective ways to prevent the flu and other flu-like illness, such as dietary interventions, making sure your vitamin D and gut flora are optimized, being more meticulous about washing your hands, getting enough exercise and sleep, and eating foods that support your immune system like oil of oregano and garlic. read more here: http://articles.mercola.com/sites/articles/archive/2013/01/22/flu-epidemic.aspx?
PLAIN SOAP AND WATER is as good or even better than those chemical hand sanitizers, many of which contain triclosan, and ingredient that is banned in Europe. I would add to that making sure you get enough sleep, and for myself, I drink a cup of green tea every day. That's seemed to help a lot of things. And laugh--laughing is good for the immune system!