Lame Science #10: Pilot comparative study on the health of vaccinated and unvaccinated 6- to 12-year-old U.S. children

Given that I teach a course on Immunology, and frequently discuss the unscientific nature of things such as homeopathy, acupuncture, and yes, vaccines-cause-autism-and-a-variety-of-other-disorders, I was intrigued when a student of mine asked if I had seen the new “study” purporting to show a link between vaccines, allergies, pneumonia, ear infections, and autism.

I told her that I had not, but committed myself to having a look at the study as soon as my exam was finished.

You may have noted that I placed the words study in quotations, as this particular article does not report on a study in any meaningful scientific context. Given that the data represent an internet survey of 666 homeschooled mothers, from this point on, the article referenced above, will be referred to as the “survey.”

If that in and of itself isn’t reason enough for you to stop reading I’ll continue to elaborate on some of the difficulties with this study below. If you’re still reading, the first noteworthy item is that these data were derived from a survey compiled from 415 mothers of 666 homeschooled children. Given that literally millions of children are vaccinated every year, and the number of homeschooled children in the U.S. is more than one million, not only is the sample not representative, it’s absolutely miniscule.

My second complaint about the study is the nature of sample itself. While I sympathize with the study’s authors in the difficulties one encounters when attempting to locate unvaccinated children, using exclusively homeschooled children is almost certainly likely to have a built in bias from the beginning. Indeed there is a strong association between homeschooled children and anti-vaccine parents, which is suppose would be a third complaint, or perhaps complaint 2b.

So what does this survey report? Taken from the abstract:

The vaccinated were less likely than the unvaccinated to have been diagnosed with chickenpox and pertussis, but more likely to have been diagnosed with pneumonia, otitis media, allergies and NDD.

To put a numerical face on that description from abstract, I’ve compiled the relevant data in the table below:

Any neurodevelopment disorder14.4%6.7%

Vaccinated Unvaccinated
Middle ear infection 19.8% 5.8%
Pneumonia 6.4% 1.2%
Allergic rhinitis 10.4% 0.4%
Other allergies 22.2% 6.9%
Eczema/atopic dermatitis 9.5% 3.6%
Learning disability 5.7% 1.2%
Attention deficit/Hyperactivity disorder 4.7% 1.0%
Any neurodevelopment disorder (autism, hyperactivity, learning disability) 10.5% 3.1%
Need allergy medication 20.0% 1.2%
Antibiotic use past 12 months 30.8% 15.4%
Fever medication 90.7% 67.8%
Hospitalization 19.8% 12.3%
Any chronic disease 44.0% 25.0%
Boys with a chronic condition
Allergic rhinitis 13.9% 7.2%
Autistic spectrum disorder 7.7% 1.9%

The data can be further summarized as follows:

Vaccinated children were significantly more likely than the unvaccinated to have been diagnosed with the following illnesses:

  • 7-fold higher odds of any neurodevelopmental disorder (i.e., learning disability, ADHD, or ASD)
  • 2-fold increase in Autism Spectrum Disorder (“ASD”)
  • 2-fold increase in ADHD
  • 2-fold increase in learning disabilities
  • 1-fold increase in allergic rhinitis
  • 9-fold increase in other allergies
  • 9-fold increase in eczema/atopic dermatitis
  • 4-fold increase in any chronic 
  • 3.8-fold increase in middle ear infections
  • 5.9-fold increased odds of being diagnosed with pneumonia compared to unvaccinated children.

No significant differences were observed with regard to:

  • Cancer
  • chronic fatigue
  • Conduct disorder
  • Crohn’s disease
  • Depression
  • Types 1 or 2 diabetes
  • Encephalopathy
  • Epilepsy
  • Hearing loss
  • High blood pressure
  • Inflammatory Bowel Disease
  • Juvenile rheumatoid arthritis
  • Obesity
  • seizures
  • Tourette’s syndrome
    And acute illnesses:

Assuming for a moment that the sample size is adequate, and that an internet survey from home school mothers regarding their children’s health outcomes is a reliable source of data, a couple of noteworthy elements are seen in the data.

Firstly it should be noted that the study relied, specifically, on physician diagnosed instances of illness; in other words, simply because a parent believed their child had pneumonia, ADHD, etc., was not adequate, a physician needed to confirm this. As it turns out the unvaccinated crowd has significant fewer visits to doctors when compared to vaccinated children. A substantial population of the homeschool crowd not only doesn’t believe in vaccines, but are often opposed to modern medicine in general. Logically, individuals that are less likely to visit a doctor are less likely to receive a diagnosis of any type of illness.

If the sample size, sample bias, and inherent flaws in this survey aren’t enough to convince you, the notion that this is the first study to investigate the long-term health outcomes of vaccination is quite absurd. Below are some other studies that address the same issue:

  • Study reporting lower rates of asthma among the vaccinated
  • Study reporting on the occurrence of allergies and infections in children and adolescents reports independence from vaccination status.
  • Study reporting on alleged cognitive benefits in vaccinated persons
  • Study reporting that vaccinated pregnant women have better birth outcomes relative to non-vaccinated mothers.
  • Another
  • And another
  • Study reports that the flu vaccine may lower heart attack risk.
    Study of 60,000 women finds flu vaccine reduces stillbirths by 50%

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