MMR and autism: another report lands on the flaw
Private Eye No 1022, 23 Feb-8 March 2001 www.private-eye.co.uk firstname.lastname@example.org
YET more headlines appeared in the press last week declaring that the controversial MMR vaccine was not linked to the dramatic rise in autism (see Eyes passim). They were triggered by another research paper, this time published on the British Medical Journals website. Once again, though, the claims are not borne out by careful scrutiny.
In this latest study US researchers compared the l990s trend of increasing autism in the UK against the pattern of take-up of MMR, first introduced in the UK in October 1988. The study of 305 children aged 12 or under with autism diagnosed in the years 1988-99 found an alarming seven-fold increase in cases of the brain disorder. In a further detailed analysis of 114 boys aged two to five years born in 1988-93, it found a four-fold increase.
Although the hike coincided with the introduction of MMR, the researchers said the increase continued steadily throughout most of the 1990s. Because near-total MMR vaccination was consistent throughout the period and exposure was therefore steady, whatever the explanation for autism, it could not be MMR. If it had been, researchers concluded, numbers would have been expected to flatten off after the initial introduction boost.
However, as the authors admit, their methods were "second-best" and "relatively crude" because what they really wanted to do was compare vaccinated and unvaccinated children but they could not find enough unvaccinated children. In fact it is a major criticism that there has never been a study of the long-term effects of immunisation using an unvaccinated control group the usual tool of sound science.
The main criticisms of the paper are that while the data for immunisation is accurate, the NHS data for autism on which the study relies is anything but, rendering it worthless. At its crudest, if the growth rate depicted in the study continued, we would be facing a catastrophe akin to the sub-Saharan Aids pandemic.
Mark Berelowitz, consultant child psychiatrist and co-author of the first paper to raise questions about the MMR vaccine and regressive autism, puts it succinctly. Responding to the BMJ he says: "The authors claim to have evidence that the incidence has risen seven-fold in 10 years (from 0.3 to 2.1 cases per 10,000 person years). Projecting this forward, by the year 2040 the incidence will be 5,000 per 10,000 person years, and soon thereafter every child born will develop autism.
"Alternatively, this is a dramatic blip covering just a 10 year period only, and the increase will not continue. In that case me blip can only be explained by an environmental cause. Either their autism data is flawed, or there is an important environmental pathogen that can cause temporary fluctuations in the incidence of autism, or the world is facing an epidemic which will make HIV and BSE seem like small problems."
There are other concerns too:
the study concentrated on boys, who have a higher incidence of autism;
observed levels of autism may differ from true levels, given the complexities and differences in diagnosis;
if immunisation is a suspect for the "environmental" trigger, there are other vaccination factors which may distort the trends and which are not accounted for in the research. For example, the introduction of the Hib vaccine on top of other child vaccines in 1992; the -massive 1994 catch-up programme, when seven million children were vaccinated or revaccinated against a perceived measles threat; and the introduction of a two-dose schedule for MMR in 1996. Some of the families now taking legal action against drug companies claim their children were damaged by both of these exercises;
better diagnosis followed the introduction of MMR, skewing the "trend".
In any event no one least of all Dr Andrew Wakefield, whose work with children suffering rare bowel disease and regressive autism led him to raise questions over MMR is suggesting that all autism is triggered by vaccination.
But newspapers reporting the research described it as a "blow to researchers led by Wakefield" and said it was further reassurance about the safety of MMR. Nothing could be further from the truth.
What all this highlights is the need for the kind of long-term international research that the governments own scientists suggested was needed (see Eye 1021)
"to settle the question of any possible association between autism and MMR". The government seems to have forgotten this, however, in its determination to deny parents the right to single vaccines and to promote MMR.
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