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5 studies that show vaccines cause autism

5 studies that show vaccines cause autism

Posted 4/22/2015

No, really, they don'tNo, really, they don'tIn the wake of yet another study showing that vaccines do not cause autism, there has been a flurry of activity on social media linking to studies that reportedly show that they do.

The reality is that you can find a study that "proves" just about anything if you look hard enough to find one but don't bother to read past the abstract. Studies which are said to demonstrate a link either do not do so, have a tiny sample size or suffer from critical flaws.

For comparison here are just three studies which show that there is no link between vaccines and autism:

1. Vaccines for measles, mumps and rubella in children

Cochrane Database of Systematic Reviews 2012, Issue 2

This review looked at the evidence presented in 5 randomised controlled trials, 1 controlled clinical trial, 27 cohort studies, 17 case-control studies, 5 time-series trials, 1 case cross-over trial, 2 ecological studies, and 6 self controlled case series studies assessing the effectiveness and safety of the MMR vaccine. In all, about 14,700,000 children were involved.

The review found no significant association between MMR and any of: autism, asthma, leukaemia, hay fever, type 1 diabetes, gait disturbance, Crohn's disease, demyelinating diseases, or bacterial or viral infections.

2. Vaccines are not associated with autism: An evidence-based meta-analysis of case-control and cohort studies

Vaccine, Volume 32, Issue 29, 17 June 2014

Five cohort studies involving 1,256,407 children, and five case-control studies involving 9,920 children were included in this analysis. No relationship was found between vaccination and autism or ASD, or between autism and any of MMR or thimerosal or mercury.

3. Autism Occurrence by MMR Vaccine Status Among US Children With Older Siblings With and Without Autism

JAMA, 2015;313(15)

This study covered 95,000 children with older siblings. 994 of these children had ASD and 1929 of them had older siblings with ASD. Receipt of the MMR vaccine was not associated with increased risk of ASD, regardless of whether older siblings had ASD.

Now here are some of the studies which are said to show a link between vaccines and autism:

1. Hepatitis B Vaccination of Male Neonates and Autism Diagnosis, NHIS 1997–2002

Journal of Toxicology and Environmental Health, Volume 73, Issue 24, 2010

This paper says that US boys vaccinated with the hepatitis B vaccine prior to 1999 had a threefold higher risk of autism compared to boys not vaccinated during that same time period. Nonwhite boys bore a greater risk.

This sounds pretty awful, but the fact it's a massive 3-fold increase which nobody else has noticed should set alarm bells ringing. Indeed, one problem with this study is its small sample size: only 7500 children were covered in the study with a mere 33 of them having autism, and a mere 9 of those were given the HepB vaccine at birth. Spurious results like this are therefore unsurprising.

The main problem, however, is that the study covers children born between 1980 and 1999. The HepB vaccine wasn't available until 1991 and wasn't in common use until 1996. Consequently, the data doesn't really help understand the influence of HepB vaccination. All this study does is confirm the undisputed observation that autism diagnoses have been rising since the 1980s.

Leftbrainrightbrain.co.uk have made a more detailed review of this study.

2. Do aluminum vaccine adjuvants contribute to the rising prevalence of autism?

Journal of Inorgic Biochemistry, 2011 Nov

This paper asserts that aluminium in vaccines has the potential to induce neuroimmune disorders, and argues that the correlation between aluminium and autism is actually a causative relationship.

This paper is written by two researchers well known for their anti-vaccine work: Lucija Tomljenovic and Christopher Shaw. I am not going to go into details since plenty of others have done a better job of discrediting this pair's work than I ever could.

However, as their names turn up a lot I will quickly summarise the problem with this paper and essentially every other paper either of this pair have produced: it's nothing more than an argument that there could be a link between aluminium and autism. It's an hypothesis, not even a theory, and there is no evidence to support the hypothesis.

3. A Positive Association found between Autism Prevalence and Childhood Vaccination uptake across the U.S. Population

Journal of Toxicology and Environmental Health, Volume 74, Issue 14, 2011

This paper argues that it is the large number of vaccines children receive which causes autism. It looks at the relationship between the proportion of children who received the recommended vaccines by age 2 years and the prevalence of autism or speech or language impairment (SLI) in each US state from 2001 and 2007 and determines that there is a statistically significant relationship.

Again, at first glance this might look persuasive. But the problem with the paper is its manipulation of the data to force an association with doesn't exist.

Here's a scatterplot, helpfully produced by neuroskeptic, of the raw data used in the paper. It's a graph of vaccination rates in 2-year old children against autism and SLI rates 6 years later.

It's quite clearly random with no link whatsoever between the vaccination data and the autism data. In fact, if you do the maths, it has a correlation factor of 0.012 (measured on a scale from 0 to 1).

The paper only manages to force out a relationship by "compensating" for effects such as pollution, family income, ethnicity and who knows what else by various strange adjustments to the data.

The only thing this paper proves is the adage concerning "lies, damn lies, and statistics".

Here are a few more dissections of the paper from scienceblogs, Liz Ditz, and leftbrainrightbrain.

4. B-lymphocytes from a population of children with autism spectrum disorder and their unaffected siblings exhibit hypersensitivity to thimerosal

Journal of Toxicology, 2013

This paper says that people with autism and their siblings have an increased hypersensitivity to thimerosal.

Ignoring the fact that this does not demonstrate any causative link between vaccines (with or without thimerosal in them) and autism, the study covered a total of just 11 families. ELEVEN!

5. Abnormal measles-mumps-rubella antibodies and CNS autoimmunity in children with autism

Journal of Biomedical Sciences, 2002 Jul-Aug

This paper asserts that autoimmunity to the central nervous system may cause autism. The researchers found elevated levels of MMR antibodies in autistic children and linked this to automimmune problems and from there to autism.

The most obvious problems with this paper is its tiny sample size. Only 125 autistic children and 92 control children were studied. However, the real problems only emerge with closer study.

Paul Offit, in his book "Autism's False Prophets", points out that the research is fundamentally flawed in that the test used to detect measles antibodies did not actually detect them, skewing the results. Unsurprisingly, therefore, attempts to replicate the research have shown "no evidence of persisting measles virus in peripheral blood mononuclear cells from children with autism spectrum disorder".

 

These are just 5 of the many papers that allege or argue a link between vaccines and autism. The truth is that all the papers which do so suffer from significant flaws, do not demonstrate a link and have been contradicated by better, larger and more in-depth studies.

Despite outliers such as these, the research is clear: vaccines do not cause autism.