Oh, FFS. No. It's not. A small amount of the mercury compound thiomersal was included in many vaccines as a preservative once upon a time, but has now been removed from all mandatory vaccines (a very few optional ones still use it). I note that it wasn't removed due to any evidence of ill effect (not all mercury compounds are created equal, and the ethylmercury that gets released from thiomersal is FAR less toxic than the methylmercury coming from fish) but simply due to public pressure. Anyway, it's long gone.
