I've gotten a flu shot myself for at least the last 25 years, and it's worked for me in all but one of those. My daughter was born 10 years ago with a chronic pulmonary disease, so our whole family, including little sis, has gotten them ever since. It's just not worth running the risk of getting that sick. (I tell you the year I did -- we ALL did -- it was DREADFUL!!)
The flu shots given are dead viruses that can help lesson the severity of a flu if your prone. If the preservatives are of concern than ask for the single shot dose without thermasol. Anyone with a comprimised immune system needs help. So why not the flu shot?
Aluminum (additive to promote antibody response), formaldehyde (disinfectant), ethylene glycol (antifreeze) phenol (disinfectant, dye) benzethonium chloride (antiseptic) and methylparaben (antifungal, preservative), along with thimerosal in some vaccines are good enough reasons for me to avoid the flu vaccine. Eating well and taking proper precautions like washing your hands is the best way and most cost effective way at preventing the flu. I will never get the flu vaccine.