A new study has found no association between infant and prenatal exposure to thimerosal, a mercury-containing preservative used in a number of vaccines, and autism. In an article published in the medical journal Pediatrics, the authors wrote that thimerosal in vaccines “does not increase the risk for autism spectrum disorder (ASD)”. They actually found that children with ASDs had had less exposure to thimerosal-containing vaccines than the children in their study who did not have an ASD.

The scientists examined managed care organization records and carried out interviews with parents of 256 children who had been diagnosed with an autism spectrum disorder according to a standardized personal evaluation. 752 children of the same age who did not have an ASD were also assessed in the same way.

They found, in fact, that higher-than-average exposures to thimerosal were less common in children with autism compared to the non-autism group. Babies vaccinated with more thimerosal-containing vaccines up to the age of 7 months, as well as those receiving more such vaccinations up to the age of 20 months appeared to be less likely to develop an autism spectrum disorder, compared to those who received no thimerosal-containing vaccines during the same periods of life.

One in every four parents is afraid of vaccinating their children because of a perceived autism risk.

This study is the latest of almost 20 to find no association between childhood vaccinations and autism, using a variety of methods and data sources – they all say there is no evidence of any link between thimerosal-containing vaccines and autism risk.

In this latest study, 14 scientists were tasked by the CDC (Centers for Disease Control and Prevention) to look into any association between thimerosal-containing vaccines and autism spectrum disorders. The researchers said they found no link, regardless of whether the child had been vaccinated while still in the womb (in utero) or during their first 20 months of life.

The authors concluded:

In our study of MCO members, prenatal and early-life exposure to ethylmercury from thimerosal-containing vaccines and immunoglobulin preparations was not related to increased risk of ASDs.

The authors stress that focus should shift to other potential causes for the rise in the number of people with an ASD in the USA and most parts of the world.

Autism is known as a complex developmental disability. Experts believe that Autism presents itself during the first three years of a person’s life. The condition is the result of a neurological disorder that has an effect on normal brain function, affecting development of the person’s communication and social interaction skills.

People with autism have issues with non-verbal communication, a wide range of social interactions, and activities that include an element of play and/or banter.

What is ASD? – ASD stands for Autism Spectrum Disorder and can sometimes be referred to as Autistic Spectrum Disorder. In this text Autism and ASD mean the same. ASDs are any developmental disabilities that have been caused by a brain abnormality. A person with an ASD typically has difficulty with social and communication skills.

A person with ASD will typically also prefer to stick to a set of behaviors and will resist any major (and many minor) changes to daily activities. Several relatives and friends of people with ASDs have commented that if the person knows a change is coming in advance, and has time to prepare for it; the resistance to the change is either gone completely or is much lower.

Autism is a wide-spectrum disorder – Autism (or ASD) is a wide-spectrum disorder. This means that no two people with autism will have exactly the same symptoms. As well as experiencing varying combinations of symptoms, some people will have mild symptoms while others will have severe ones. Below is a list of the most commonly found characteristics identified among people with an ASD.

Click here to read more about autism and ASD in more detail, including how its implications for social skills, empathy, physical contact, loud noises, smells and lights, speech, repetitive behaviors, and learning.

Click here to read about Asperger syndrome.

“Prenatal and Infant Exposure to Thimerosal From Vaccines and Immunoglobulins and Risk of Autism”
Cristofer S. Price, ScM, William W. Thompson, PhD, Barbara Goodson, PhD, Eric S. Weintraub, MPH, Lisa A. Croen, PhD, Virginia L. Hinrichsen, MS, MPH, Michael Marcy, MD, Anne Robertson, PhD, Eileen Eriksen, MPH, Edwin Lewis, MPH, Pilar Bernal, MD, David Shay, MD, MPH, Robert L. Davis, MD, MPH, Frank DeStefano, MD, MPH
Published online September 13, 2010
PEDIATRICS (doi:10.1542/peds.2010-0309)

Written by Christian Nordqvist