The spin doctors at the the British Committee on Safety of Medicines (CSM) and the Public Health Laboratory Service (PHLS), the folks responsible for vaccine policy in Britain, have been busier than usual.
In response to the evidence presented by Andrew Wakefield and his team at the Royal Free Hospital in London, demonstrating a link between autism and the MMR triple vaccine, the PHLS and the CSM put together two epidemiological studies which, naturally, dismissed this link out of hand. Hundreds of press releases were churned out at the same time, and Chief Medical Officer Dr Jeremy Metters was quickly dispatched to publicly assure the British public that "on the basis of accumulated evidence", there is no link, and that's that.
British parents, who, incidentally, have been running away from this vaccine in droves, could now rest easy in their beds knowing that the combined jab was indeed safe and the Wakefield evidence a bizarre anomaly.
The actual PHLS study is not quite so definitive as this statement would have us believe. Basically, the authors took a group of 498 children diagnosed as autistic in eight North Thames health districts and compared clinical data about them with their immunisation records to see if there was any sort of temporal relationship between the onset of their autism and receipt of the MMR jab. They also looked at the overall incidence of autism to determine whether there was an increase after the introduction of MMR in Britain.
The design of the study is, by the authors' own admission, poor. This kind of broad sweep epidemiology only really works when you are looking for gross patterns in populations.
Furthermore, unlike most scientific studies, the actual numerical data aren't presented in the published paper, making it impossible for outsiders to critically evaluate it to the full.
Several groups believe the PHLS has incorrectly analysed its own data and in general made a hash of their interpretation.
There is no doubt that autism has increased dramatically in this area. In the main chart of the study, the incidence of autism increases steadily from a level of some three born in 1979 to 50 born in 1992. According to the group Allergy Induced Autism (AIA), autism has risen 25 per cent every year.
The authors of the study say that this increase in autism cases began in children born before the MMR was launched in 1988 and so is unrelated. However, Paul Shattuck, the head of the autism unit at the University of Sunderland, says that interpretation ignores the PHLS's own "catch up" policy of vaccinating children born in 1985 and 1986 with the MMR at age two or three, even if they'd had the single measles jab at 13 months. If you take these children into account, there would be a significant rise in autism cases in children born in 1986, if MMR had anything to do with it. Indeed, there is such a large spike in the study's chart.
The study also examined the timing of the first parental concern about their child's autistic behaviour. The data clearly show a large peak of parental concern six months after the MMR vaccine. Nevertheless, this cluster was subsequently explained away as reflecting the difficulty parents experience pinpointing when their child's symptoms first developed.
There is no doubt that these studies are designed as spindoctoring to prop up the flagging reputation of MMR. In March 1999, the State of California released a report demonstrating that the incidence of autism had increased by 273 per cent among young children and had a sudden and alarming increase just at the point that MMR was introduced, says the AIA.
The only way that we will ever know for sure about the MMR is to subject it to a proper, scientific study comparing groups given the shot against those not vaccinated. But then truth never did have anything to do with spin.