Watching the news makes you want to run out to get a flu shot until you realize that the shot contains mercury (very toxic to the brain), doesn't prevent the flu, and increases the likelihood of a hospital visit. See http://drdavidbrownstein.blogspot.com/2012_09_01_archive.html. I'm not making this up!!
It's great to read the blog of Dr. David Brownstein. He has a lot to say about the flu vaccine (http://drdavidbrownstein.blogspot.com/2012_09_01_archive.html), the dangers of osteoporosis medicines like Fosomax and Actinel, the iodine deficiency in this country, and more.
Your best protection is to avoid sugar, artificial sweeteners, starchy foods, and get to sleep at night. Sun exposure during the day raises your vitamin D levels which increases your immunity. Or you can take vitamin D3 daily, depending on what your blood tests show you need. If you are sick, take 50,000 iu's a day plus 10,000 -20,000 vitamin C, and up to 25,000 units of vitamin A daily for a few days.