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Calls to Action

Geraldine Dawson Letter to Newsweek

March 09, 2009

In its issue dated March16, 2009, Newsweek published an edited version of letter from Autism Speaks Chief Science Officer Geraldine Dawson about autism and vaccines.

Click here to read the letter as published in Newsweek. The complete letter appears below.

To The Editor,

Sharon Begley accurately summarizes some key research findings in the eleven years since a controversial U.K. study claimed a link between autism and vaccines (“Anatomy of a Scare,” February 23), but she fails to capture the complexity of the current scientific perspective on the confounding topic of autism.

The question of a link between vaccination and autism first arose in the 1970s and has been explored ever since. It is possible that there is truth somewhere among all of the accusations and fears surrounding the hypothesized link between autism and vaccines, but that truth is unlikely to be captured in the simple hypothesis that MMR or thimerosal is the cause of autism or its dramatic increase in prevalence. Researchers started with these simple hypotheses and, through a series of studies, disproved them. During the last decade, we've learned that autism is much more complicated than we thought. It involves many genetic and environmental factors. It is not one disease and does not have one cause that will explain even a majority of cases. Piece by piece, we will have to follow each and every one of these leads if we are going to discover the multiple causes of autism and effective treatments. Over this same time, our hypotheses regarding the possible connection between autism and vaccines have evolved. The most plausible hypothesis is that if we do find that vaccines play a role in the onset of autism, it will be in only a very small minority of children with very specific and rare medical or genetic conditions. But, simply put, we must continue the learning.

The bottom line is that parents can be reassured that, for the vast majority, vaccines are safe and important for preventing major childhood diseases. Still, scientists must – and will -- continue to work behind the scenes to identify those few children who might respond differently to vaccines from the large majority. Exploring all scientifically plausible hypotheses will only increase parents' confidence in the vaccine program and the medical establishment, in general. Rather than “letting through demons,” as Ms. Begley fears, keeping the right doors open will provide us with a better understanding of autism spectrum disorder and build trust between parents and the medical community. This sense of collaboration and transparency can only accelerate our progress in finding treatments, prevention strategies, and cures for this challenging disorder.


Geraldine Dawson, Ph.D.
Chief Science Officer, Autism Speaks
Research Professor, Department of Psychiatry
University of North Carolina at Chapel Hill
Professor Emeritus, University of Washington