MMR and Autism

Measles graphicThe continuing outbreak of measles in South Wales has once more drawn attention to Andrew Wakefield, the man who did more than most to create a panic over MMR and autism. He was aided and abetted by scare stories in the media which presented Wakefield as a lone hero, battling against an establishment cover up on behalf of the children. Many of those now affected missed out on vaccines because of this scare. According to Dr Roland Napier, consultant epidemiologist for Public Health Wales, speaking to the Daily Telegraph

”There was a sustained campaign against MMR by the local evening paper [the South Wales Evening Post in the late Nineties] and my colleagues noted at the time that its circulation area had a proportionate fall in vaccinations compared to other regions in Wales. So there is a connection,”

This time round the media are united in condemning Wakefield while failing to acknowledge or apologize for their part in promoting the MMR Hoax. But if you look in the comments section of the online articles you will find a small but determined minority of people who still believe the lies and distortions so faithfully repeated by the media in the past. Andrew Wakefield himself has summarized these for us in a statement published on Age of Autism.

Blame the Government.

Wakefield’s argument then and now is that the government was to blame for withdrawing single vaccines and taking away choice after he raised doubts about MMR and recommended single vaccines. This ignores the fact that prior to MMR there had never been a single vaccine for mumps in the UK. Furthermore, replacing the two MMR doses with six separate doses one year apart would have left more children unprotected for longer, even assuming that vaccine take up did not suffer from six doctors visits instead of two. All the evidence suggests that uptake is lower for single doses and children often do not complete the course. And Wakefield has never addressed the question of how, if any component parts of the MMR vaccine are implicated in autism or bowel disease, giving them separately would mitigate that risk.

MMR is not safe

Two versions of MMR vaccine were withdrawn because the mumps component based on the Urabe strain carried a risk of developing aseptic meningitis. This was known before they were introduced but the rate of infection, 1 in 100,000 was much less than the natural rate of infection from mumps itself. They were only withdrawn in favour of vaccines using the Jeryl Lynn strain of mumps, which does not cause aseptic meningitis, when a more intensive study found a rate of 1 in 3000 for aseptic meningitis among children following MMR vaccination in Nottingham. Even then if the Jeryl Lynn strain had not been available, the health authorities would have continued with the vaccine because the rate of aseptic meningitis in actual mumps is around 1 in every 10 cases.

But Wakefield’s target has always been the measles component of MMR, not mumps or rubella. According to official statistics in the 20 years prior to the introduction of MMR there were 436 recorded deaths from measles in England and Wales. In 1988, the year MMR was introduced, there were 16 deaths. In the next twenty years there were 28 recorded deaths in England and Wales. Apart from death, there is the misery of the disease itself and the risk of side effects like convulsions (1 in 200:  MMR 1 in 1000), meningitis/encephalitis (1 in 5000: MMR 1 in 1000000 ), bleeding disorders (1 in 3000: MMR 1 in 100000). These figures reflect the safety of MMR based on 500 million doses given worldwide over a thirty year period.

MMR can cause autism

Wakefield bases this assertion on the decision by the US Vaccine Court to award damages to a small number of “children whose autism followed vaccine-induced brain damage. A recent government concession in the US Vaccine Court confirms that the parents’ claims were valid all along.”

He does not mention the Autism Omnibus Proceedings at the same court. A team of lawyers recruited thousands of parents who believed that vaccines had caused their child’s autism. They selected their strongest cases to present three general causation theories of autism resulting from either MMR, Thimerosal containing vaccines, or a combination of the two. Expert witnesses were summoned on both sides. Surprisingly Andrew Wakefield was not called as an expert by the petitioners. Every case was lost and the theories were dismissed. The successful individual petitioners mentioned by Wakefield have never argued that vaccines cause autism. That case was lost. They followed a different path. The vaccine court includes a list of table injuries that cover recognized side effects like encephalitis. You do not have to prove that the vaccine caused these injuries, only that they occurred within a specified timescale after the vaccine was administered. Some parents have persuaded the court that a) the injury occurred within the necessary timescale and b) their child is permanently disabled as a result. Hence the generous compensation payments.

But this does not prove that vaccines cause autism. According to Wikipedia

From 1988 until March 3, 2011, 5,636 claims relating to autism, and 8,119 non-autism claims, were made to the VICP. 2,620 of these claims, one autism-related, were compensated, with 4,463 non-autism and 814 autism claims dismissed; awards (including attorney’s fees) totaled over $2 billion. The VICP also applies to claims for injuries suffered before 1988; there were 4,264 of these claims of which 1,189 were compensated with awards totaling $903 million.[9]

Taking a prevalence figure for autism of 1 per cent in the general population we would expect a similar proportion among children winning claims for vaccine injury. So twenty or thirty individual cases of autistic children winning their claims would not be unusual. It is not evidence that vaccines cause autism any more than the “814 autism claims dismissed” are evidence vaccines do not cause autism. The evidence is in the science and we now have 15 years of accumulated evidence that does not support the vaccine autism hypothesis.

Wakefield ends by offering “to debate any serious challenger on MMR vaccine safety and the role of MMR in autism, live, in public, and televised.”  That is how politicians operate not scientists. Science proceeds via research, publication and academic discourse. In all these arenas Wakefield’s ideas have been tested and found wanting. Giving him the opportunity to grandstand on television may help to rally the faithful. It will add nothing to our understanding of vaccines or autism.

One thought on “MMR and Autism

  1. Pingback: Why are Wakefield’s views on MMR still news? | Penumbrage

Leave a Reply

Your email address will not be published. Required fields are marked *