Administration of thimerosal-containing vaccines to infant rhesus macaques does not result in autism-like behavior or neuropathology

Bharathi S. Gadad, Wenhao Li, Umar Yazdani, Stephen Grady, Trevor Johnson, Jacob Hammond, Howard Gunn, Britni Curtis, Chris English, Vernon Yutuc, Clayton Ferrier, Gene P. Sackett, C. Nathan Marti, Keith Young, Laura Hewitson, and Dwight C. German
PNAS published ahead of print September 28, 2015 https://doi.org/10.1073/pnas.1500968112

  1. Edited by Matthew State, University of California, San Francisco, CA, and accepted by the Editorial Board August 9, 2015 (received for review January 15, 2015)

See related content:

This article has a correction. Please see:

Significance

Autism is a childhood neurodevelopmental disorder affecting approximately 1 in 70 children in the United States. Some parents believe that thimerosal-containing vaccines and/or the measles, mumps, rubella (MMR) vaccine are involved in the etiology of autism. Here we gave nonhuman primate infants similar vaccines given to human infants to determine whether the animals exhibited behavioral and/or neuropathological changes characteristic of autism. No behavioral changes were observed in the vaccinated animals, nor were there neuropathological changes in the cerebellum, hippocampus, or amygdala. This study does not support the hypothesis that thimerosal-containing vaccines and/or the MMR vaccine play a role in the etiology of autism.

Abstract

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder. Some anecdotal reports suggest that ASD is related to exposure to ethyl mercury, in the form of the vaccine preservative, thimerosal, and/or receiving the measles, mumps, rubella (MMR) vaccine. Using infant rhesus macaques receiving thimerosal-containing vaccines (TCVs) following the recommended pediatric vaccine schedules from the 1990s and 2008, we examined behavior, and neuropathology in three brain regions found to exhibit neuropathology in postmortem ASD brains. No neuronal cellular or protein changes in the cerebellum, hippocampus, or amygdala were observed in animals following the 1990s or 2008 vaccine schedules. Analysis of social behavior in juvenile animals indicated that there were no significant differences in negative behaviors between animals in the control and experimental groups. These data indicate that administration of TCVs and/or the MMR vaccine to rhesus macaques does not result in neuropathological abnormalities, or aberrant behaviors, like those observed in ASD.

Footnotes

  • ↵1Present address: The School of Social Work, University of Texas at Austin, Austin, TX 78712.

  • ↵2To whom correspondence should be addressed. Email: dwight.german{at}utsouthwestern.edu.

  • Author contributions: G.P.S., K.Y., L.H., and D.C.G. designed research; B.S.G., W.L., U.Y., S.G., T.J., J.H., H.G., B.C., C.E., V.Y., C.F., and D.C.G. performed research; B.S.G., U.Y., G.P.S., C.N.M., and D.C.G. analyzed data; and B.S.G., G.P.S., C.N.M., L.H., and D.C.G. wrote the paper.

  • The authors declare no conflict of interest.

  • This article is a PNAS Direct Submission. M.S. is a guest editor invited by the Editorial Board.

  • This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1500968112/-/DCSupplemental.

Freely available online through the PNAS open access option.

Back to top
Article Alerts
Email Article
Citation Tools
Request Permissions
Pediatric vaccines and autism
Bharathi S. Gadad, Wenhao Li, Umar Yazdani, Stephen Grady, Trevor Johnson, Jacob Hammond, Howard Gunn, Britni Curtis, Chris English, Vernon Yutuc, Clayton Ferrier, Gene P. Sackett, C. Nathan Marti, Keith Young, Laura Hewitson, Dwight C. German
Proceedings of the National Academy of Sciences Sep 2015, 201500968; DOI: 10.1073/pnas.1500968112
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
Proceedings of the National Academy of Sciences: 116 (8)
Current Issue

Submit

Jump to section

You May Also be Interested in

Nonmonogamous strawberry poison frog (Oophaga pumilio). Image courtesy of Yusan Yang (University of Pittsburgh, Pittsburgh).
Putative signature of monogamy
A study suggests a putative gene-expression hallmark common to monogamous male vertebrates of some species, namely cichlid fishes, dendrobatid frogs, passeroid songbirds, common voles, and deer mice, and identifies 24 candidate genes potentially associated with monogamy.
Image courtesy of Yusan Yang (University of Pittsburgh, Pittsburgh).
Active lifestyles. Image courtesy of Pixabay/MabelAmber.
Meaningful life tied to healthy aging
Physical and social well-being in old age are linked to self-assessments of life worth, and a spectrum of behavioral, economic, health, and social variables may influence whether aging individuals believe they are leading meaningful lives.
Image courtesy of Pixabay/MabelAmber.