Public health officials like Ms. Ehresmann, who herself has a son with autism, have been trying for years to convince parents like Ms. Rupp that there is no link between thimerosal - a mercury-containing preservative once used routinely in vaccines - and autism.
They have failed.
The Centers for Disease Control and Prevention, the Food and Drug Administration, the Institute of Medicine, the World Health Organization and the American Academy of Pediatrics have all largely dismissed the notion that thimerosal causes or contributes to autism. Five major studies have found no link.