Even were thimerosol (or thiomersal) present in the vaccine, it is extremely doubtful that it should form any cause for concern.
Firstly, thimerosol is an organo mercury compound -not elemental mercury.It metabolises in the body to ethylmercury and thiosalicylate. Ethylmercury as an organomercuric compound could be toxic, in a sufficiently high dose, but as Paracelcus noted all those years ago - "the dose makes the poison".
In your typical influenza jab, the amount of thimerosol as a preservative would be present in concentrations of around 0.01%, so in an IM vaccine with a total volume of 0.5ml the amount of ethyl mercury your body is exposed to would be 50 microgrammes. And this vaccine is administered once, maybe twice a year. You will be exposed to much,much, much more ethyl and methyl mercury as a consequence of general living and diet.
As Slaney has pointed out though, thimerosol is or has been phased out, particularly for vaccines aimed at children, on the basis of the precautionary principle.
Someone made the comment that "Big Pharma" makes lots of money from vaccines.They make very much more from selling pills than they do vaccines - vaccines are expensive to test and manufacture. Indeed, a big area of public health concern is the lack of willing manufacturers nowadays.
http://content.health...content/24/3/622.full