Z’s coming up on the time for his MMR vaccine. As with most of the jabs he’s gotten to date, it’s just a thing that we do, a right of passage designed to keep my child healthy. Not something I would have thought about much at all, except that I’ve had a little bird (who shall remain nameless) chirping in my hear about the MMR vaccine and autism. It’s a link that I’d heard about once or twice, generally as being absolutely mythical based on apocryphal stories by grieving parents. But, when it’s your own child you think twice and just to quiet that little quiver of doubt in the tin-foil hat part of my brain, I decided to take a look at the science behind autism and MMR. It turned out to be quite a story.
It all stems from a single scientific publication. In 1998 a paper by Andrew Wakefield of the Royal Free Hospital in London and twelve colleagues was published in the British medical journal The Lancet purporting a link between the MMR vaccine and childhood autism. Wakefield and his colleagues hypothesized that the vaccine caused an irritation to the bowel, making it more permeable to the proteins delivered by the vaccine allowing them to leak into the bloodstream. The researchers claimed that these proteins acted as toxins and caused serious developmental brain damage, particularly autism.
Wakefield’s paper was riddled with problems and the scientific community was almost immediately skeptical. It was based on an extremely small sample, only twelve patients. While Wakefield did find histological evidence to support intestinal damage in the autistic children, there was no control group to compare against. The study noted that “onset of behavioural symptoms was associated, by the parents, with the (MMR vaccine) in eight of the 12 children.” In other words, the researchers relied on parents of autistic children’s memories of events rather than health care professionals. Parents that were understandably upset and far from objective observers. Finally, thepublished article stopped well short of concluding that there was a causal link between the MMR vaccine and autism. However, when Wakefield spoke to the press he made no such disclaimer.
Predictably, the Lancet paper set off a firestorm in the British and world media. For example, in just six months in 2002 in Britain there were over 500 stories about MMR and autism. The MMR vaccine and any other vaccines containing a mercury based compound known as thimerosol (TCV) came under scrutiny by the press. Unfortunately, these stories rarely featured a rigorous examination of the facts on the ground. Every time that one of these stories hits the press more parents opt out of vaccination. Since 1999, the number of parents in the U.S. opting out of the MMR vaccination has nearly tripled. Cases of measles, which had been eliminated in the U.S., are on the rise. There were 72 cases reported in ten states in the first half of 2008. This can be causally linked to people opting out of the vaccine. More striking however, is that nearly 900,000 people worldwide, many of them children, died from measles in 1999. That figure was down to 345,000 in 2005 due largely to an initiative by the Measles Initiative to make the MMR vaccine more available in the third world. The resurgence of measles in North America should be a cold hard reality check – this is what happens when you do not get your children vaccinated.
What makes things worse is that Wakefield lied.
Since the publication of the original Lancet paper, ten of the twelve authors have retracted the conclusions claiming that Wakefield went too far in claming a causal relationship between the vaccine and autism. Wakefield, who was sacked from his post at the Royal Free Hospital in 2001, has since been charged with professional misconduct. This is based in part on the 2004 revelation by The Times (London) that some of the parents who took part in the original study had been recruited by a UK attorney planning to file suit against MMR manufacturers. Four or five of the children were covered by the legal aid study and Wakefield had been awarded £55,000 to assist their case by finding scientific evidence of the link. Wakefield did not tell his colleagues or medical authorities about this case and personally received £400,000 for his troubles.
The effort to sort out the science that Wakefield corrupted has been intensive. Scores of papers have been published refuting Wakefield and his colleagues’ results. There have been large, well controlled epidemiologic studies in North America, Europe, Asia all of which conclude the same thing. For example, one of these studies looked at over half a million Danish children, 20% of whom were not vaccinated. Compare this to Wakefield’s study that looked at 12 children, all of whom were autistic and had been vaccinated. All of these studies come to the same conclusion – there is no significant causal link between the MMR vaccine (or and thimeresol containing vaccines) and childhood autism. There have been no studies published in reputable scientific journals that claim such a link since Wakefield’s paper. The truth is that incidents of autism are increasing and have been for the last half century or so. Autism has a genetic component, but the marked recent rise suggests that there is some environmental factor involved. The first signs of autism in children are generally detected between one and two years of age, the same time period in which most children receive their MMR vaccinations – this is one of the problems in dispelling the myth of a link. But, except for Wakefield’s compromised work all studies undertaken have concluded that the rise in cases of autism is independent of the increased use of the MMR vaccine. Yet the fear surrounding the vaccine remains.
Which brings us around to two common themes here on afreeman.org – crappy journalism and scientists inability to communicate. The fear surrounding MMR is largely being propagated by the media, whose obsession with “balance” insures that in every story about MMR and autism both sides of the issue will be presented. In this case one side is the truth – that there is absolutely no link between autism and the MMR vaccine – and the other side is the lie fabricated by one greedy and corrupt scientist and his gullible colleagues. A lie that is, presumably unknowingly, being propagated by a press obsessed with sensationalism. Thus, having made its way into our cultural consciousness (it’s been on the TV, so it must be true) it is nearly impossible to rid ourselves of the misinformation. And well meaning people suffer. This happens, as it did for me, when little birds have friends who have friends who blame the vaccine for their child’s autism. It also happens when public figures, like presidential candidate John McCain, recite as truth something they read somewhere.
The media is not completely at fault, however. They are simply doing their job to inform and entertain the public, with the latter becoming increasingly important. Most scientists fail miserably to effectively communicate the realities of their research. Take for example, this reply to a Horizon program on the MMR/autism drama. Dr. Neville Goodman, writing in the British Medical Journal, responds to this program with the frustration that a lot of scientists feel with the media still spewing this swill. He writes:
“In 2002, according to the Child Accident Prevention Trust, more than 36 000 children were hurt in road accidents and around 200 were killed… five cases annually of childhood leukaemia may be associated with power lines. But perspective is precisely what is rejected by personal experience: so we have illogical campaigns to uproot speed cameras, to move pylons, and to give single vaccines.”
Goodman’s mistake is that he callously dismissed the “five cases of leukemia associated with power lines”. A mistake that many scientists make, we are so obsessed with statistics and data that we tend to forget the individual subjects of our research, we neglect to treat them not as numbers but as human beings. The families of those five children who developed leukemia by living under power lines probably do not feel that their campaigns are illogical. Nor would parents of autistic children consider their belief that the MMR vaccine destroyed their children illogical. There is no link, but we as scientists need to endeavour to educate – loaded with the facts, but deployed with compassion – rather than mock, deride or scorn.
As you may have guessed, Z will be getting his MMR vaccine next month. I feel good that I’ve done the research, that I’ve looked at the primary literature and the “other side”. (Guess that Ph.D. was good for something).