According to organizations representing parents of autistic children, officials at the Centers for Disease Control and Prevention (CDC) may have conspired to conceal data connecting the use of vaccines to developmental disorders in children.
Groups such as the National Autism Association, Generation Rescue, A-Champ, NoMercury, Moms Against Mercury and AutismOne have long argued that a mercury-based chemical called thimerosal, used as a preservative in some vaccines, can cause children to develop autism.
Recently, these groups sponsored a full-page ad in USA Today arguing that the CDC knew "that the ambitious immunization schedule begun in the 1990s, nearly tripling the amount of mercury injected into our children, created an epidemic of autism in America."
They are basing their accusation on internal CDC and FDA e-mails obtained through the Freedom of Information Act, and are demanding that criminal charges be brought against the officials involved.
The CDC argues that there is no scientific evidence that vaccinations contribute to autism, and that the benefits of vaccination also outweigh the risks.