Thimerosal, the Centers for Disease Control and Prevention, and GlaxoSmithKline

To the Editor .— I am the first author of a recent article on a study undertaken by the Centers for Disease Control and Prevention (CDC) to screen for a potential link between thimerosal-containing vaccines and neurodevelopmental delays.1 The article has been subject to heavy criticism from antivaccine lobbyists. Their criticism basically comes down to the following two claims: the CDC has watered down the original findings of a link between thimerosal-containing vaccines and autism, and GlaxoSmithKline (GSK) has hired me away from the CDC so as to convince me to manipulate the data further before publication. Because I was responsible for nearly all aspects of this study, including study design, data gathering, data analysis, and writing of the article, I wish to give my opinion on these claims. These are my personal opinions and do not represent the opinion of the CDC or GSK. Did the CDC water down the original results? It did not. This misconception comes from an erroneous perception of this screening study and other epidemiological studies. The perception is that an epidemiological study can have only 1 of 2 outcomes: either an …