Association Between Thimerosal-Containing Vaccine and Autism | Autism Spectrum Disorders | JAMA | JAMA Network
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Clarkson TW. The toxicology of mercury.  Crit Rev Clin Lab Sci.1997;34:369-403. Scholar
Stratton K, Gable A, McCormick MC. Immunization Safety Review: Thimerosal-Containing Vaccines and Neurodevelopmental Disorders. Washington, DC: National Academy Press; 2001.
Plesner AM, Ronne T. The childhood vaccination program: background, status and future [in Danish].  Ugeskr Laeger.1994;156:7497-7503. Scholar
Ronne T. The Danish vaccination program for children [in Danish].  Ugeskr Laeger.1997;159:1584-1585. Scholar
Malig C. The Civil Registration System in Denmark. Bethesda, Md: International Institute for Vital Registration and Statistics; 1996. IIVRS Technical Paper No. 6.
Madsen KM, Hviid A, Vestergaard M.  et al.  A population-based study of measles, mumps, and rubella vaccination and autism.  N Engl J Med.2002;347:1477-1482. Scholar
Munk-Jorgensen P, Mortensen PB. The Danish Psychiatric Central Register.  Dan Med Bull.1997;44:82-84. Scholar
Andersen TF, Madsen M, Jorgensen J, Mellemkjoer L, Olsen JH. The Danish National Hospital Register: a valuable source of data for modern health sciences.  Dan Med Bull.1999;46:263-268. Scholar
Knudsen LB, Olsen J. The Danish Medical Birth Registry.  Dan Med Bull.1998;45:320-323. Scholar
Clayton D, Hills M. Statistical Models in Epidemiology. Oxford, England: Oxford University Press; 1993.
Ball LK, Ball R, Pratt RD. An assessment of thimerosal use in childhood vaccines.  Pediatrics.2001;107:1147-1154. Scholar
Pichichero ME, Cernichiari E, Lopreiato J, Treanor J. Mercury concentrations and metabolism in infants receiving vaccines containing thimerosal: a descriptive study.  Lancet.2002;360:1737-1741. Scholar
Bertrand J, Mars A, Boyle C, Bove F, Yeargin-Allsopp M, Decoufle P. Prevalence of autism in a United States population: the Brick Township, New Jersey, investigation.  Pediatrics.2001;108:1155-1161. Scholar
Brief Report
October 1, 2003

Association Between Thimerosal-Containing Vaccine and Autism

Author Affiliations

Author Affiliations: Danish Epidemiology Science Centre, Department of Epidemiology Research (Messrs Hviid, Wohlfahrt, and Dr Melbye) and Medical Department (Dr Stellfeld), Statens Serum Institut, Copenhagen, Denmark.

JAMA. 2003;290(13):1763-1766. doi:10.1001/jama.290.13.1763

Context Mercuric compounds are nephrotoxic and neurotoxic at high doses. Thimerosal, a preservative used widely in vaccine formulations, contains ethylmercury. Thus it has been suggested that childhood vaccination with thimerosal-containing vaccine could be causally related to neurodevelopmental disorders such as autism.

Objective To determine whether vaccination with a thimerosal-containing vaccine is associated with development of autism.

Design, Setting, and Participants Population-based cohort study of all children born in Denmark from January 1, 1990, until December 31, 1996 (N = 467 450) comparing children vaccinated with a thimerosal-containing vaccine with children vaccinated with a thimerosal-free formulation of the same vaccine.

Main Outcome Measures Rate ratio (RR) for autism and other autistic-spectrum disorders, including trend with dose of ethylmercury.

Results During 2 986 654 person-years, we identified 440 autism cases and 787 cases of other autistic-spectrum disorders. The risk of autism and other autistic-spectrum disorders did not differ significantly between children vaccinated with thimerosal-containing vaccine and children vaccinated with thimerosal-free vaccine (RR, 0.85 [95% confidence interval {CI}, 0.60-1.20] for autism; RR, 1.12 [95% CI, 0.88-1.43] for other autistic-spectrum disorders). Furthermore, we found no evidence of a dose-response association (increase in RR per 25 µg of ethylmercury, 0.98 [95% CI, 0.90-1.06] for autism and 1.03 [95% CI, 0.98-1.09] for other autistic-spectrum disorders).

Conclusion The results do not support a causal relationship between childhood vaccination with thimerosal-containing vaccines and development of autistic-spectrum disorders.