Thursday, 25 September 2008

Fear and Vaccination in London

Author's note: After my successful foray into soapboxing with the LHC story, I decided to get back up on the box again to trumpet my current hypothesis. Science, the scientific method and scepticism are misunderstood by almost everyone and something has to be done. For more evidence of just how bad things are, check out the ongoing research into the dangers of dihydrogen monoxide. The research itself is satire (sorry to spoil the fun, but I certainly don't want people to think I don't get it). The reactions of the public are the really frighetning part. Anyway, on to the self-righteous ranting.

In 1998 a British-based surgeon, Dr. Andrew Wakefield published a research paper in which he and his team tentatively identified a bowel disorder associated with autism which he coined “autistic enterocolitis” and speculated (a very important word there) that this might be caused by vaccination with the MMR vaccine. Most people are roughly aware of what MMR is. The measles, mumps and rubella triple vaccine. It is a mixture of the three viruses, alive but weakened to the point that they’re not even able to infect infants. They do however cause the recipient’s immune system to generate lots of cells and antibodies that will basically squash the three viruses should they ever be seen again. The need for vaccination against these three diseases is an easy case to make. Measles in adults can cause brain damage. Mumps may cause infertility in males, especially kids. Rubella, if it infects the unborn through the mother, can cause a wide range of birth defects. These complications don’t occur often- but the viruses are so infectious that those rare cases would be a big deal in any highly populated country.

Cause and Effect

So MMR was suggested to have an influence on autistic intestinal inflammation, but there was more. According to Wakefield’s paper, there also appeared to be a connection between the time of administration of MMR to a child and emergence of autism, though that element of the study was retrospective. The paper itself did not rock the boat in the mainstream media, th
ough the scientific community began criticising it immediately. The connection between MMR and autism was not clear, and the study group was small. Just twelve children, all selected because they had autism. At best, that sort of study would represent a starting point for some more solid research. To be meaningful and to make that connection really clear we’d need thousands of examples, and we’d to be able to compare our results with loads of non-autistic kids.

It wasn’t until Wakefield decided to jump outside of the peer-review system that things began to go bad. I discussed in a previous posting how science makes its way into the mainstream media. I even included a flow chart, which I’ll reproduce now. What Dr. Wakefield did was follow the path on the far right. Skipping all external controls and critique he instead decided to talk directly to the press. And what he had to say would cause a sensation. He called for a halt to administration of the MMR vaccine in favour of vaccinating for each of the three diseases separately over an extended time of several years. His stated reasoning was that he believed that MMR might be causing Autism. The initial response in the media was muted. The press release and an accompanying video released by Wakefield’s hospital drew some attention. Wakefield found himself defending his work in letters to the journal that had published his paper, Lancet. In 2000, Wakefield published more papers pushing his MMR hypothesis. Then in 2001, something snapped. Perhaps it was the publicity, the momentum built in the last couple of years. Perhaps Wakefield’s recent high-profile exit from his hospital position (a “mutual decision”) was noticed. Perhaps some of his new research papers pushed the right buttons. Whatever it was, the MMR and autism story hit the mainstream.

What Grows in Darkness

The newspapers went wild, particularly in the UK. By 2002, the stories in the press questioning the safety of MMR numbered in the thousands. Few dealt with the inconvenient peer-reviewed research papers that refuted Wakefield’s findings and the controversy dominated health reporting for several years. Here was a piece of news based on the (very carefully worded) concerns of a single surgeon. But somehow the line (in the Daily Mail at least) became “Scientists Fear MMR Link to Autism”. “One Scientist Cautiously and Inappropriately Suggests MMR Link to Autism” is not very catchy perhaps, but the fear mongering sentiment went further than headlines and permeated the reporting. As a direct result, MMR vaccination rates in the UK fell to 80% by 2003. In some urban areas of London, the rate was as low as 65%. When we learn a little about how vaccination works these, figures become even more alarming.

Vaccination is not 100% effective on a person-to-person basis, though it is usually above 99% effective. This is generally not an issue however, as vaccination also serves to protect the unvaccinated by eliminating the pool possible hosts for a given virus. Because your neighbours are all immune, your chances of even encountering the virus, let alone contracting it, are dramatically reduced. The virus is much less likely to be passed around by accident. This effect is called “herd immunity”. For the three viruses that MMR protects against, the threshold for good herd immunity is around 95% of the population. With the rate of uptake so low in 2005, the risk was rapidly increasing that herd immunity would collapse, resulting in large scale epidemics amongst the roughly 20% of unvaccinated children and the 1% for whom the vaccine had failed to take.

Predictably, the epidemics began around 2000, when the earliest signs of concern had begun to filter through to the public. Measles epidemics were reported in Ireland, Austria and Italy. Most significantly, measles incidences in the UK have increased steadily over the last eight years. Although the increase may appear minimal (from 56 cases per year in 1998 to an estimated 900 cases per year by 2006) the disease was declared “endemic” in the British population earlier this year. This means that the virus is now circulating freely in the population without need for re-infection from outside sources. So anyone without immunity is immediately at much greater risk. Herd immunity is degenerating. There is also evidence that travellers to and from Europe triggered minor outbreaks in the United States. Mumps is on the rise again also, primarily hitting age-groups who passed through infancy prior to the introduction of MMR. Some 70,000 cases were reported between 2004 and 2006. There were a handful of deaths as a result of the measles and mumps resurgences. Three deaths were reported in Ireland, one death in the UK and two cases of brain damage. Not many, but a reminder to us of times when these diseases were a true threat.

The degeneration of herd immunity is just the first step, there is another risk associated with allowing these viruses to become endemic. For every infected person there are literally billions of mumps, measles or rubella viruses in their system. The more viruses there are, the faster they reproduce. The faster they reproduce, the more often they mutate. With part of the population vaccinated and part not vaccinated, what we are doing is presenting the mutating viruses with an obstacle to overcome. The risk is growing that one of these three viruses may undergo the mutation required to evade MMR entirely.

In 2004, ten of Wakefield’s co-authors on the 1998 paper withdrew their support for the work. Since the first publication, at least twenty peer-reviewed research or review papers have discredited the MMR link to autism. Wakefield’s suggested new “autistic enterocolitis” has been dismissed by autism researchers as a common symptom of the condition. Ten years after the controversy began, MMR is not the only vaccine to fall victim to the resurgent paranoia and disillusionment with modern medicine, though this is a trend which predates the MMR scare. Some papers continue to lead a crusade against any proposals for new “multivalent” vaccines that, like MMR, would combine protection from several diseases.

Apportioning Blame

It was a need for a simple cause which ultimately brought the MMR crisis into being. But the fact is, there’s no known single cause for autism. And nor are the causes of the vaccination crisis as clear as they seem. It would be easy to point the finger at Dr. Wakefield. He’s certainly not free of blame. Wakefield’s 1998 study was prompted when he was approached by solicitors representing a group planning to sue MMR manufacturers for causing the autism. According to a Sunday Times report in 2006, Wakefield received money from that group to perform his 1998 study and it appears that some of the study participants were sourced by them too. It is also alleged that Wakefield’s hospital, who were quick to back his findings and arrange press contact, also received money in the form of legal aid. It seems clear from interviews at the time that Wakefield was aware of the fine balance of risks associated with his bold statement. He was aware that switching from the use of MMR to using three vaccines over a number of years very significantly increases a child’s risk of contracting one of the diseases in that time. Wakefield’s point was that the risk of autism outweighed both the fact that his results were unclear and the fact that his suggested course of action brought great risks. He should absolutely not have been going public with his poorly-conceived idea, yet his language in the press release and interviews was actually quite suitably cautious. The subtlety was lost on many news outlets. Rather than exhibit caution themselves, they perpetuated a fear-laden story that has done incalculable damage to public health in Europe. Many of these are the same papers that, years later, are now assassinating Wakefield’s character in light of professional misconduct charges. Ultimately we have to blame pretty much everybody; parents looking for simple answers, lawyers looking for litigation, a surgeon with a bias, a hospital looking for publicity, a media willing to spin anythi
ng to sell papers. Not to mention the confused reactions of most GPs and politicians (a blog in itself). And then there’s us. The scientists fought the good fight on the day, sure. But it could be argued that our aloofness from the public has created a culture in which science is only noticed when it is sensational; a culture in which the people have neither the education nor the inclination to view science with proper scepticism. It’s conceivable that just one of those groups had it in them to prevent this whole huge mess. Instead we are now facing continued vaccine paranoia and a dangerous resurgence of diseases we once had on the run.

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