A two-phased population
epidemiological study of the safety of thimerosal-containing vaccines: a
follow-up analysis.
Geier DA, Geier
MR.
MedCon, Inc., U.S.A.
Background: Thimerosal is an
ethylmercury-containing preservative in vaccines. Toxicokinetic studies
have shown children received doses of mercury from thimerosal-containing
vaccines (TCVs) that were in excess of safety guidelines. Previously, an
ecological study showing a significant association between TCVs and
neurodevelopmental disorders (NDs) in the US was published in this
journal. Material/Methods: A two phased population-based epidemiological
study was undertaken. Phase one evaluated reported NDs to the Vaccine
Adverse Event Reporting System (VAERS) following thimerosal-containing
Diphtheria-Tetanus-acellular-Pertussis (DTaP) vaccines in comparison to
thimerosal-free DTaP vaccines administered from 1997 through 2001. Phase
two evaluated the automated Vaccine Safety Datalink (VSD) for cumulative
exposures to mercury from TCVs at 1-, 2-, 3-, and 6-months-of-age for
infants born from 1992 through 1997 and the eventual risk of developing
NDs. Results: Phase one showed significantly increased risks for autism,
speech disorders, mental retardation, personality disorders, and
thinking abnormalities reported to VAERS following thimerosal-containing
DTaP vaccines in comparison to thimerosal-free DTaP vaccines. Phase two
showed significant associations between cumulative exposures to
thimerosal and the following types of NDs: unspecified developmental
delay, tics, attention deficit disorder (ADD), language delay, speech
delay, and neurodevelopmental delays in general. Conclusions: This study
showed that exposure to mercury from TCVs administered in the US was a
consistent significant risk factor for the development of NDs. It is
clear from these data and other recent publications linking TCVs with
NDs that additional ND research should be undertaken in the context of
evaluating mercury-associated exposures and thimerosal-free vaccines
should be made available.
PMID: 15795695 [PubMed - as supplied by
publisher]