both of my sons get it. My Oldest didnt get his until he was about 15 months, because he was under 6 months old during the period they like to give the shot. my youngest will be 2 in Jan and he has gotten in 2x...when he was about 10 months old and again this year...
I am a healthcare worker and recommend the shots
Also, about the mercury response, they haven't actually used mercury/thermosil in shots in years....any vaccine you give you child has chemicals in it. but not mercury or thermosil.."Thimerosal has been largely removed from pediatric vaccines in recent years in what health officials have described as a precautionary measure. (This has been accomplished as drug makers have voluntarily switched from multi-dose vials of vaccine, which require a chemical preservative like thimerosal, to single-dose containers.)" that is from an article dated early in 2005
The vaccines are made from the previous years strain of the virus, they are never 100% effective over this years strain because the virus mutates. But it helps decrease your chances of getting it, or if you do get it you are MUCH more likely to get more of a cold like feeling than the full blown flu.
Good luck and I would ask you pedi any questions or concerns you have!