All information containing new and unprecedented conclusions begins by being violently opposed by those who create the prior information and those who subscribe heavily to it. This is very much the case with the link between Autism Spectrum Disorder and vaccines; mainly the MMR vaccine and other thimerosal-containing vaccines.
It is clear that the stance from mainstream science is that there is no link between vaccines and autism. You can find more about that here. But for many people this does not dispel all concern. Dr. Hooker, PhD, PE says that the recent U.S. Centers for Disease Control and Prevention (CDC) study on vaccines and autism is