Abnormal Brain Connectivity Spectrum Disorders Following Thimerosal Administration: A Prospective Longitudinal Case-Control Assessment of Medical Records in the Vaccine Safety Datalink.

Background: Autism spectrum disorder (ASD), tic disorder (TD), and hyperkinetic syndrome of childhood (attention deficit disorder [ADD]/attention deficit hyperactivity disorder [ADHD]) are disorders recently defined as abnormal connectivity spectrum disorders (ACSDs) because they show a similar pattern of abnormal brain connectivity. This study examines whether these disorders are associated with exposure to thimerosal, a mercury (Hg)-based preservative.
Methods: A hypothesis testing case-control study evaluated the Vaccine Safety Datalink for the potential dose-dependent odds ratios (ORs) for diagnoses of ASD, TD, and ADD/ADHD compared to controls, following exposure to Hg from thimerosal-containing Haemophilus influenzae type b vaccines administrated within the first 15 months of life. Febrile seizures, cerebral degeneration, and unspecified disorders of metabolism, which are not biologically plausibly linked to thimerosal, were examined as control outcomes.
Results: On a per 25 μg Hg basis, cases diagnosed with ASD (OR = 1.493), TD (OR = 1.428), or ADD/ADHD (OR = 1.503) were significantly ( P < .001) more likely than controls to have received increased Hg exposure. Similar relationships were observed when separated by gender. Cases diagnosed with control outcomes were no more likely than controls to have received increased Hg exposure.
Conclusion: The results suggest that Hg exposure from thimerosal is significantly associated with the ACSDs of ASD, TD, and ADD/ADHD.
Competing Interests: Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: There are no competing financial interests. Three of the four authors have been involved in vaccine/biologic litigation. Dr. Mark Geier, Mr. David Geier, and Dr. Janet Kern have been involved as consultants and expert witnesses for petitioners in the No-Fault National Vaccine Injury Compensation Program (NVICP) and have also been consultants and expert witness for plaintiffs in civil litigation. The cases that Dr. Janet Kern, Mr. David Geier, and Dr. Mark Geier participated in involved the outcome of autism, and none of the other neurodevelopmental outcomes examined in this study. Dr. Mark Geier and Mr. David Geier are currently involved in no cases, have not been involved in any cases for several years, and have no plans to be involved in any future cases. Dr. Janet Kern is not involved in any current cases and has no plans to be involved in any future cases.