This is one of those ‘banker topics’ in that you can bank on the fact that it will come up again and again on this blog. Like the Creationism/Evolution debate, the Science has now taken a back seat to what has essentially become a political/culture war. So recently, I was embroiled in a massive argument on a Public Health Ethics forum over whether vaccines cause Autism. At first I noticed some slightly dubious comments by someone about vaccine inefficiencies in the developing world. Initially, I didn’t think this was anti- vax conspiracy theory stuff, merely professional criticism of healthcare systems in general and perhaps how the vaccine schedule needs to improvements (..yada yada yada). Still, I was sufficiently uncomfortable with them to direct their attention to this article which looked at how vaccines have been a phenomenal Public Health tool around the world and the adverse side-effects of which haven’t been substantively demonstrated.
I was expecting people to take it on board and enlighten me with various criticisms of the structures and how the Institutions involved with Immunization processes need to improve in the developing world. Instead what I got was the most verbatim regurgitation of the standard anti vaccine conspiracy theories that are out there (especially in popular media with Jenny Mccarthy, Jim Carey and Robert Kennedy Jr being quite prominent in promoting this hoax in North America). So I will briefly attempt to go over this (pseudo) controversy and how it has developed over the years.
The Plural of Anecdote is Anecdotes, NOT Data
Perhaps the most infamous of these Vaccine scares is the claim that Measles Mumps and Rubella (MMR) Vaccine causes Autism. This kicked off when in 1998 Andrew Wakefield (along with others) published this paper in the Medical Journal The Lancet. This was a case-series study looking at 12 kids who had the Vaccine and had later gone on to develop Autism. Now it has to be acknowledged that the conclusion of that particular study merely posited an ‘association between MMR and Autism’. But subsequent to its publication, Mr Wakefield decided to hold press conferences whipping up the frenzy in the media and the press about the ‘link’ between the Autism and the MMR vaccine. [It has since emerged that Andrew Wakefield was found in breach of ethics and conflicts of Interest by the British General Medical Council and the Lancet also retracted that paper based on that investigation — But be that as it may] Even if this was not the case, one has to look at the evidence-base and the strength of the study. And that was essentially based on 12 Clinical Anecdotes which is not enough to establish the link between MMR and Autism. The reason for this is because firstly this is NEITHER a rare risk exposure (i.e about 93% of the population get vaccinated) NOR is this a rare outcome (from 1 in 50 to 1 in 200 children develop Autism). For example if an Astranaut developed a third eye, you would count that as both rare risk exposure and rare outcome. In that case 12 anecdotes would be very compelling evidence to take the hypothesis ‘space travel gives you a third eye’ seriously . In this case however, 12 anecdotes don’t tell us anything. What we need is a big study involving a large sample size. That should be the basis of the evidence that ultimately judges this claim. Hence this wasn’t a particularly useful study (again that’s putting all the breaches aside) to begin with.
The Danish Study
And that large study was published in 2002, in Denmark called “Madsen et al” which looked at a cohort study of more than 500,000 children (as opposed the 12 anecdotes) …400,000 of which received MMR and 100,000 didn’t. And then they looked at the rates of Autism in both groups. The conclusion they found was the rates of Autism on both group were the same. Again when more rigor was applied to this hypothesis, it failed to check out. Of course the Anti-Vax lobby do not acknowledge this and are hell-bent on discrediting that study not by scientific evidence but ad hominem attacks on authors and secret cabals behind the scenes siphoning money here there and everywhere. Respectful Insolence tackles that in detail. The thing to remember is, the scare was started by a study that looked at 12 cases. When it was examined in much more detail (Large sample size always good for accuracy) the claims failed to meet the emprical standard. That is the bottom line in Science.
Thimerosal Mercury Preservative
Thimerosal (Mercury preservative in Vaccine) causing Autism is now the latest of the conspiracy theories trotted out by the same crowd. So much so, that the pressure generated from these groups got the Center for Disease Control (CDC) to take it out of their vaccine schedule. Now what would you expect to see after Thimerisal was taken out of the vaccines if it actually caused autism?. You would undoubtedly see a plateauing of the rates of autism, followed by a decrease, wouldn’t You? If it is indeed the Thimerosal. In reality what was observed was that the rates of autism remained the same. In fact, the real rates of Autism may have even increased. So it could not possibly have been the Thimerosal. But that inconvenient fact does not seem satisfy the anti-vax lobby.
In itself, the CDC backing down and ditching Thimerosal is not a big issue because in the US there are more efficient ways to implement Vaccine distribution. However in the developing world, places like Uganda where such distribution infrastructures aren’t available; these Preservatives are of much greater importance. But governments over there look at the US taking it out of their vaccines, inevitably reach the conclusion that they must lead to autism. And that misunderstanding prompts the to compromise their Immunization Infrastructure – something much more important over there than in the West.
The “Big Pharma = Pure Evil” Mantra
The Philosophical underpinning of these claims usually stems from a politically charged belief that big pharma is basically conspiring to make you and your kids sick so that they can take your money selling you their pills. Certainly, the Pharmaceutical Industries are no angels.(I wrote a post already in which I was critical of them in passing). However, the ant-vax view of them doesn’t even amount up to be Cartoon-ish. Sure you can expect a level of bias to creep in if studies are funded by Big Pharma. But ultimately you have to review the methodologies involved. Just because there is a profit motive involved doesn’t mean that the study therefore will be bogus. It should be fully disclosed and taken into consideration (publication-bias) but there are ways to evaluate the strengths and weaknesses of studies no matter who funds them.
As it happens, if you visit the websites of the anti vax groups such as Age of Autism or Generation Rescue you will be bombarded with products claiming to cure Autism. One could make the argument that there is a financial element to their opposition to vaccines (and peddling of their own autism products/services). Valid though this maybe, ultimately it is the horrific lack of scientific peer reviewed evidence that should take precedence when both debunking their claims about vaccines and evaluating their ‘quack-remedies’. (and not who advertises on their site). That is really a side-issue designed to dumb down the debate on the evidence (at least in the Vaccine issue).
The Dangerous Circularity
There seems to be a dangerous circularity of arguments from people when they oppose vaccines. They say ‘why do we need vaccinations for things like Polio, Measles, Mumps etc when these diseases are so rare?’. And you cant help but wanting shout out at them “Well why the f*** do you think they ARE very rare”. Sure there are other factors that have aided the decline of these infectious diseases, but their ‘rarity’ is chiefly due to the Vaccines. Unfortunately this circularity post the MMR hoax has led to a decline in Vaccination rates in the past decade which low and behold saw an uptick in Whooping cough and Measles in parts of the UK and USA in the decade just finished. If we let these childish notions about vaccinations go unchallenged they can have pretty dire consequences.
The Diagnosis Effect
Another argument often trotted out about this is, that the rates of Autism have increased post 1990. Why is it so? Could it be that our understanding of Autism has increased since that period. When previously it was labelled something else, it is now classified under Autism. It is not beyond the realms of possibility that we have a more nuanced understanding of this disease now. But this doesn’t necessarily mean the rates of Autism have increased from prior to 1990 and the only cause of that are vaccinations. That is pretty tenious claim and requires well controlled large-scale studies and not circumstantial innuendo- as seems to be the mode of operation of many of these Anti-Vaccine groups.
The Opportunity Cost of Self-Indulgent Nonsense
Perhaps the saddest thing about this unicorn-chasing, is the diversion of resources away from the trying to discover the real causes of Autism. So much energy and capital has already been spent trying to debunk this, yet these groups remain on the offensive, still. And the press and media have fanned the flames giving them the credence they never deserved. All this creates an element of doubt among parents as to whether to vaccinate their kids or not – and that is a potentially harmful development for us all.
I haven’t really done this topic justice in this one post, however I will be revisiting it from time to time.