ICAAC. The findings were the same as the main results in the final paper (DeStefano, 2004).

The publication of the manuscript took over 3 years (January 1999-June 2002). The first draft was completed in January 1999, and it was cleared by CDC and ready for submission to a scientific journal by October 2000 (the paper was not accepted by the first journal and was submitted to a second journal in May 2001) (DeStefano, 2004). The second journal also did not accept the submission, so it was sent to a third journal (Journal of Pediatric Infectious Disease) in August 2001, was accepted in February 2002, and published in June 2002 (DeStefano, 2004; DeStefano et al., 2002).

Safety of Thimerosal-Containing Vaccines: A Two-Phase Study of Computerized MCO Databases

The 2003 study by Verstraeten and colleagues explored possible associations between thimerosal (a preservative that contains ethylmercury) in vaccines and neurodevelopmental disorders. The study was intended to be an initial screen of possible associations; a detailed study would be planned if any associations were identified (DeStefano, 2004). The final results based on one MCO’s data indicated that cumulative exposure to thimerosal at the age of 3 months resulted in a significant association with tics (Verstraeten et al., 2003a). In data from a second MCO, an increased risk of language delay was associated with cumulative exposure at the ages of 3 months and 7 months (DeStefano, 2004). Those findings could not be replicated with data from a third, comparable MCO. None of the analyses showed a significant increase in risk of attention deficit hyperactivity disorder (ADHD) or autism (DeStefano, 2004).

Review of Timeline

The concern about thimerosal-containing vaccines and possible health effects received a lot of attention in summer 1999 when a joint Public Health Service (PHS) and American Academy of Pediatrics statement recommended reduction or elimination of thimerosal in vaccines as a precautionary measure (CDC, 1999b). That was suggested because it had been determined that with some vaccination schedules at that time, a child could have exceeded the Environmental Protection Agency’s guidelines for exposure to methylmercury. In August 1999, a National Vaccine Advisory Committee meeting was convened at the National Institutes of Health (NIH) to review the research then available on the question and to recommend additional research (Egan, 2000). After the meeting, a working group of the PHS, including some external experts, was established to



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