Many parents think that since the AAP”s edict back in 1999 that mercury and its derivative preservative Thimerisol have been eliminated from all childhood vaccines.  Unfortunately, many available flu shots still have Thimerisol.  Your doctor may tell you it is just a trace amount, which it does sound small when you say anything in “micrograms”, but if we look at the EPA guidelines for mercury exposure, of which Thimerisol is 50% mercury, it is still way too much for our little children, and even for adults.