Look at your source and see if they are credible.
first they say that vaccines contain mercury which they do not they contain thimerosal (sodium ethylmercurithiosalicylate) that is not mercury. Further in the body it is metabolized to ethylmercury which is still not mercury. It still has a whole ethy group. There are entire compounds that by slight deviation can mean the difference between fatal and essential.
While ethylmercury has some links to not being that great for you, the fact that the article is so grossly negligent to call a compound mercury (because everyone knows it is bad stuff) tends to hint that their is either a political agenda or that are looking to scare up a story.
Further, thimerosal was removed from all children vaccines in the 90's so even if there was a link, there is no valid reason today to not vaccinate you child.
Personally, (if it where mercury) I would much rather expose my child to even a small dose of mercury to prevent a return to the infant mortality rates of a century ago.
Can you imagine a time when it was unusual for a family to not loose a child. Ponder that for a moment, then weight it against the risks. Up until vaccination technology, a family would almost assuredly loose a child in their lifetime.
My grandmother lost her older sister at 10 years old to a vaccinatable disease. That was the reality back then The math says it all, something changed infant mortality rates and medical science has testable reproducible results that say they where responsible for that change, until the witch doctors can provide reproducible results, I am sticking with the guys that are using science.