Debunked: “VACCINES CAUSE AUTISM”
This dangerous myth all started when a fraudulent study led by Dr Andrew Wakefield was published in the highly respected medical journal The Lancet in 1998. He studied children diagnosed with autism after receiving the combined vaccination for measles, mumps and rubella (MMR). He claimed that the vaccine caused autism and bowel disorders. Parents quickly stopped vaccinating their children. Another theory falsely implicates the use of thiomersal, a mercury-based vaccine preservative, with autism.
In the years that followed, more rigorous studies found no link between the MMR vaccine and autism: Wakefield was wrong. Ecological studies looked at the numbers of vaccinated children versus the number of children with autism. In Canada, autism rates increased while MMR vaccination rates went down. Sweden and Denmark removed thiomersal from vaccinations in 1992, but autism rates continued to rise. Retrospective cohort studies looked back through medical records to find links. One Danish study analysed over 537,000 children but found no link between their vaccination date and autism diagnosis. Prospective cohort studies followed children after vaccination to see if they went on to develop autism. In Finland doctors found 31 children with symptoms described by Wakefield but none became autistic. Then there was a meta-analysis conducted by Taylor et al that gathered results from more than 1.25 million children. They found no link either.
Measles, mumps and rubella are dangerous infections that can cause deafness, meningitis, brain swelling and death. In 2010, The Lancet retracted Wakefield’s paper, with the UK’s General Medical Council striking Wakefield off the medical register for serious professional misconduct in the same year.
Bad Science
Why was Wakefield’s research eventually discredited?
Statistics
There were only 12 children in Wakefield’s study — not enough to draw a firm conclusion.
No control data
The children in Wakefield’s study weren’t compared to children who hadn’t had the MMR vaccine.
Memory
The paper relied on parental anecdotes, which are not a reliable form of evidence.
Vague conclusions
The conclusions made in the paper were speculation and were not based on solid evidence.
This article was originally published in How It Works issue 108, written by Charlie Evans
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