I get mine at work (they have a day where nurses come in and give them out for free) and I know they have a notice that states if you are allergic to eggs do not get the shot. I've also seen notices that state the shot has no eggs in it, so I believe they have both kinds.
I've never really been the type of person to believe that vaccinations are bad for you or are in some way going to harm you. I ended up feeling back to normal a few days after the shot. Like somebody else said anything that jars your immune system a little bit could upset any sort of autoimmune illness. I had a cold last week and my symptoms got worse then too. But they are getting back to normal now. I've been getting the Hepatitis series of shots and those dont seem to affect me at all though.
I get the shots just in case I need to go back on immunosuppressants as I was on Imuran and had to get off of it. Dr's always recommend getting the shots if you are on any of those drugs.