Exposing a fetus or young infant to vaccines with the mercury-based preservative called thimerosal does not increase the risk for autism, according to a study published Monday in the journal Pediatrics.
"This study adds to the evidence that thimerosal-containing vaccines do not increase a child's risk of developing autism," lead study author, Dr. Frank DeStefano of the Centers for Disease Control and Prevention (CDC) tells CNN.
Researchers studied the medical records of 256 children diagnosed with autism and 752 typically developed children born between January 1994 and December 1999. The children were between 6 and 13 years old when the medical data was reviewed – 85 percent of them were boys. The research concluded that there was no evidence that children exposed to the mercury in the vaccines were at risk for getting autism.
The debate over any links between vaccines and autism - a behavior problem triggered by brain damage - couldn't be more contentious. The great majority of medical opinion holds that vaccines don't cause autism. However, many of the same experts don't dispute that vaccines can, in rare instances, cause brain damage.
Our examination of federal vaccine court decisions over the years reflects this. Children who end up with autistic symptoms or autism have won vaccine injury claims over the years-as long as they highlighted general, widely-accepted brain damage; not autism specifically. But when autism or autistic symptoms are alleged as the primary brain damage, the cases are lost.
That doesn't make sense to families who see autism as a specific form of encephalopathy. But it makes perfect sense to the University of Pennsylvania's Dr. Brian Strom, who has served on Institute of Medicine panels advising the government on vaccine safety. He says the prevailing medical opinion is that vaccines are scientifically linked to encephalopathy, but not scientifically linked to autism.
"The fact that a person suffers autism and encephalopathy does not mean that the vaccine caused both of them," says Dr. Strom. "Even if it caused the encephalopathy, that may or may not have been the cause of the autism--those are two different questions."