The highly respected Institute of Medicine has completed its Immunization Safety Review: Thimerosal-Containing Vaccines and Neurodevelopmental Disorders (October 2001). They strongly urge removing all mercury from vaccines, as part of the overall effort to reduce mercury exposure in children.
Nevertheless, they found no evidence that the thimerosal form of mercury that has been used in vaccines has caused autism, attention deficit disorder, speech delays, or other problems in children. This is the best result I could have hoped for.
Thankfully, in the US all of the routinely recommended vaccines are already available in thimerosal-free forms.