I had the following discussing with a friend online recently. I publish it below, slightly edited for clarity. The topic was whether vaccinations cause autism.
Friend: I believe in vaccinating children, but I also think it can cause a lot of other issues. There are kids who get injuries from them , so a lot of parents are scared as to not wanting to vax .
So they make up stuff so some parents Don’t vax and babies get sick and die
Dustin: Any evidence supporting your idea?
Friend: Yes, I have seen on TV and from doctors and the news I’m not a doctor and I don’t know all there is on vaccines; there are pros and cons to vaccinating your kids, as with everything else
Dustin: What did you evidence was presented on TV and the news?
Friend: A doctor talking about it and a parent who child was fine until they vaccinated, and that child changed. I think it has to do with genes and maybe the environment , but I don’t know for sure. I listen to both sides. I’m not against it all.
Dustin: So the thing about the child who was fine until that child was vaccinated. That is a case of post hoc, ergo propter hoc.
Friend: Dustin, I don’t know those words, dude.
Dustin: It’s a logical fallacy that says, “Event Y happened after event X; therefore, event X cause caused event Y.”
Friend: I don’t know science.
Dustin: I did have a long list of academic articles that debunked the idea of vaccine causing autism.
Friend: Okay maybe send me some so I can read on them, please.
Dustin: Let me find them real quick. Hold on.
Autism Occurrence by MMR Vaccine Status Among US Children With Older Siblings With and Without Autism
http://jama.jamanetwork.com/article.aspx?articleid=2275444
The Journal of the American Medical Association
April 2015
Safety of Vaccines Used for Routine Immunization of U.S. Children: A Systematic Review
http://www.ncbi.nlm.nih.gov/pubmed/25086160
Pediatrics
August 2014
Vaccines are Not Associated with Autism: An Evidence-Based Meta-Analysis of Case-Control and Cohort Studies
http://www.ncbi.nlm.nih.gov/pubmed/24814559
Vaccine
June 2014
On-time Vaccine Receipt in the First Year Does Not Adversely Affect Neuropsychological Outcomes
http://pediatrics.aappublications.org/cgi/content/abstract/125/6/1134
Pediatrics
Smith, M and Woods, C
June 2010
Vaccines and Autism: A Tale of Shifting Hypotheses
http://www.journals.uchicago.edu/doi/full/10.1086/596476
Clinical Infectious Diseases
Offit, Paul and Gerber, Jeffrey S.
February 2009
Immunization Safety Review: Vaccines and Autism
http://www.iom.edu/reports/2004/immunization-safety-review-vaccines-and-autism.aspx
Institute of Medicine
May 2004
Adverse Effects of Pertussis and Rubella Vaccines: A Report of the Committee to Review the Adverse Consequences of Pertussis and Rubella Vaccines
http://www.nap.edu/catalog/1815/adverse-effects-of-pertussis-and-rubella-vaccines
Institute of Medicine
1991
Too Many Too Soon?
Addressing Parents’ Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant’s Immune System?
http://pediatrics.aappublications.org/cgi/content/full/109/1/124
Pediatrics
Offit, Paul A., Quarles, Jessica, et al.
2002
Immunization Safety Review: Multiple Immunizations and Immune Dysfunction
Institute of Medicine
February 2002
Cellular Immune Responses in Neonates
http://www.ncbi.nlm.nih.gov/pubmed/10763708
International Reviews of Immunology
Fadel S, Sarazotti M.
2000
Neonatal and Early Life Vaccinology
http://www.ncbi.nlm.nih.gov/pubmed/11348697
Vaccine
Siegrist CA.
2001
The Problem with Dr. Bob’s Alternative Vaccine Schedule
http://pediatrics.aappublications.org/content/123/1/e164.abstract
Pediatrics
Offit, Paul A. and Moser, Charlotte A.
January 2009
Neuropsychological performance 10 years after immunization in infancy with thimerosal-containing vaccines.
Pediatrics
Tozzi AE, Bisiacchi P, Tarantino V, De Mei B, D’Elia L, Chariotti F, Salmaso S.
January 2009
Continuing Increases in Autism Reported to California’s Developmental Services System
http://archpsyc.ama-assn.org/cgi/content/full/65/1/19
Archives of General Psychiatry
Robert Schechter, MD, MSc and Judith K. Grether, PhD
January 2008
Early Thimerosal Exposure and Neuropsychological Outcomes at 7 to 10 Years
http://content.nejm.org/cgi/content/full/357/13/1281
New England Journal of Medicine
Thompson WW, Price C, Goodson B, et al.
September 2007
Lack of Association Between Rh Status, Rh Immune Globulin in Pregnancy and Autism
http://www3.interscience.wiley.com/cgi-bin/abstract/114264055/ABSTRACT
American Journal of Medical Genetics
Judith H. Miles and T. Nicole Takahashi
May 2007
Comparison of Blood and Brain Mercury Levels in Infant Monkeys Exposed to Methylmercury or Vaccines Containing Thimerosal
Environmental Health Perspectives
Thomas M. Burbacher, PhD
April 2005
Thimerosal Exposure in Infants and Developmental Disorders: A Prospective Cohort Study in the United Kingdom Does Not Support a Causal Association
Pediatrics
John Heron and Nick Andrews, PhD and Jean Golding, DSc
September 2004
Neurotoxic Effects of Postnatal Thimerosal Are Mouse Strain Dependent
Molecular Psychiatry
M Hornig, M
June 2004
Safety of Thimerosal-Containing Vaccines: A Two-Phased Study of Computerized Health Maintenance Organization Database
Pediatrics
Thomas Verstraeten, MD
November 2003
Association Between Thimerosal-Containing Vaccine and Autism
Journal of the American Medical Association
Anders Hviid, MSc
October 2003
Thimerosal and the Occurrence of Autism: Negative Ecological Evidence from Danish Population-Based Data
Pediatrics
Kreesten M. Madsen, MD
September 2003
“Autism and Thimerosal-Containing Vaccines: Lack of Consistent Evidence for an Association”
American Journal of Preventive Medicine
Paul Stehr-Green, DrPh, MPH
August 2003
Thimerosal and Autism?
Pediatrics
Karen Nelson, MD
March 2003
Mercury concentrations and metabolism in infants receiving vaccines containing thiomersal: A descriptive study
The Lancet
Michael Pichichero, MD
November 2002
Examination of the Safety of Pediatric Vaccine Schedules in a Non-Human Primate Model: Assessments of Neurodevelopment, Learning, and Social Behavior
http://ehp.niehs.nih.gov/wp-content/uploads/advpub/2015/2/ehp.1408257.acco.pdf
Environmental Health Perspectives
February 2015
Early Exposure to the Combined Measles-Mumps-Rubella Vaccine and Thimerosal-Containing Vaccines and Risk of Autism Spectrum Disorder
http://www.ncbi.nlm.nih.gov/pubmed/25562790
Vaccine
January 3, 2015
Remembering How to Fight Measles
http://www.nytimes.com/2014/03/28/opinion/remembering-how-to-fight-measles.html?emc=eta1&_r=0
New York Times
Paul A. Offit, MD
March 2014
How to Think About the Risk of Autism
http://www.nytimes.com/2014/03/30/opinion/sunday/how-to-think-about-the-risk-of-autism.html
New York Times
Sam Wang, Ph.D.
March 2014
Lack of Association Between Measles Virus Vaccine and Autism with Enteropathy: A Case-Control Study
http://www.plosone.org/article/info%3Adoi/10.1371/journal.pone.0003140
PLoS One
Hornig M, Briese T, Buie T, Bauman ML, Lauwers G, et al.
September 2008
Measles Vaccination and Antibody Response in Autism Spectrum Disorders
Archives of Disease in Childhood
Gillian Baird, F.R.C.Paed.
February 2008
Pervasive Developmental Disorders in Montreal, Quebec, Canada: Prevalence and Links With Immunizations
Pediatrics
Eric Fombonne, MD
July 2006
MMR Vaccination and Pervasive Developmental Disorders: A Case-Control Study
The Lancet
Liam Smeeth, MRCGP
September 11, 2004
Association of Autistic Spectrum Disorder and the Measles, Mumps, and Rubella Vaccine
Archives of Pediatrics & Adolescent Medicine
Kumanan Wilson, MD, MSc, FRCP
July 2003
Neurologic Disorders After Measles-Mumps-Rubella Vaccination
Pediatrics
Annamari Makela, MD
November 2002
No Evidence for a New Variant of Measles-Mumps-Rubella-Induced Autism
Pediatrics
Eric Fombonne, FRCPsych
Autism Occurrence by MMR Vaccine Status Among US Children
This observational cohort study reports no association between the MMR vaccine and autism spectrum disorder among US children with older siblings with autism.
jamanetwork.com
Friend: So what do u think causes it.
Dustin: The idea that autism was caused by vaccines was started by a doctor who published some very, very bad research. A lot of people hang onto it because of the post hoc fallacy. What you have to do in these cases is do statistical tests to see if kids who received vaccines were significantly more likely to get autism than a control group that did not received the vaccines. As for what causes autism. . . I am pretty sure you are right when you say that it’s not simple, that there are genetic or hereditary factors and environmental factors.
Friend: Yeah I think so. I feel like it’s my fault that my daughter has autism. I just wish we could know why.
Dustin: It’s not your fault at all. It’s very complicated. I don’t think anyone one knows exactly what causes it. It does tend to run in families, but whether that’s more a “genetic” thing or an “environmental” thing is hard to say. That’s the sort of thing that they sometimes control for by using identical twin studies. The idea there is that identical twins are clones of each other, carrying almost exactly the same DNA (genetic material), so if you have them grow up in different environments (usually because of adoption), then the genetic side is controlled for by their having the same genetic material, and their environments would be the “experimental” variable.
Friend: Yeah I agree.
Dustin: Anyway, in all these studies (not just twin studies, but in those two) there is never any statistically significant difference in autism incidence in vaccinated groups (experimental group) vs. non-vaccinated groups (control groups). And even if there were ever a statistical significance, it would also be important to look at the effect size, because statistical significance only means that the difference is real, but effect size tells us how many people are affected by the difference.
I don’t think that there is anything wrong with being concerned that something like that might happen, to be worried that vaccines might cause autism, because if they did, that would be a very important thing to know. But it has been tested, and it just isn’t the case that vaccines cause autism.
I saw something interesting recently, come to think about it. Have you heard about the CRISPR gene editing technology?
Friend: No.
Dustin: CRISPR is an amazing technology. It basically RNA that can selectively “edit” DNA and turn off certain genes. They have used it to edit genes believed to be associated with autism with some very promising results. I’ll send you a link to the CRISPR thing. Thanks for talking to me about this! I get nerdy about this kind of thing.
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