Health Check: Jeremy Laurance

MMR fears stem from a scientific bungle, not a media plot

You might think there was absolutely nothing left to say about MMR – and then you hear something so odd, unexpected or surprising that it pulls you up and leaves you wondering where the argument can possibly go next.

I have had this experience several times in the past week (after being away on sabbatical for three months writing a book). The big change in that time is how the debate has shifted from the level of scientific debate to the level of anecdote.

You can read a sheaf of scientific papers, talk to all the experts and weigh up all the evidence. But, ultimately, you want to know what your neighbour, friend, doctor or Prime Minister are doing with their babies. Anecdotes are very powerful, and personal anecdotes are the most powerful of all.

That is why I was fascinated to read the letter in this week's Lancet from Professor John Walker-Smith, the senior author on the original 1998 research paper by Dr Andrew Wakefield that started the MMR and autism scare. Professor Walker-Smith, who is now retired, is one of the most distinguished paediatric gastro-enterologists of his generation. When the Royal Free Hospital succeeded in poaching him and his research team from St Bartholomew's Hospital in the mid-1990s, it caused a major upset.

The last time I saw Professor Walker-Smith was at the press conference at the Royal Free in February, 1998, called to publicise his research team's findings. It was one of the biggest public relations disasters I have witnessed. Five doctors were present, all eminent in their own field, and all with a different opinion.

I learnt later that the five had earlier rehearsed the press conference and agreed the line they would take, which was to recommend the continued use of MMR vaccine, pending on further research to investigate the causes of the inflammatory bowel disease and autism that they had found in 12 children.

But, in the actual press conference, under pressure of questioning from reporters including myself, that carefully constructed consensus fell apart. At one extreme, Dr Wakefield advised parents to choose single vaccines administered a year apart, while at the other, Professor Arie Zuckerman, adviser to the World Health Organisation on vaccination, insisted MMR had been given to millions of children world-wide and was safe.

We hapless reporters were left to fashion a coherent story out of diametrically opposed views and, news being what it is (generally bad), the headlines next morning highlighted the warning about potential risks of MMR rather than the reassurance about its safety. The rest, as they say, is history.

I labour this point, at risk of being charged with special pleading, because the press is now being accused of fomenting the current panic over MMR. While some of what has been published is, in my view, indefensible, that charge cannot be laid at the original stories on the 1998 Lancet paper. The responsibility for setting this particular hare running lies squarely with the researchers, not with the reporters. It was a monumental scientific cock-up, not a media conspiracy.

I do not remember what Professor Walker Smith had to say at that press conference four years ago. As I recall, he kept pretty quiet (it was difficult to get a word in). But in his letter to this week's Lancet, the first time he has broken his silence since, he says he continues to support MMR, "as have all the Royal Free paediatricians from the beginning", and that three of his own grandsons have had the triple vaccination.

To me, the fact that a senior scientist, who was actively involved in the research that led to the autism scare, has allowed his own grandchildren to have the MMR jab is a pretty impressive anecdote. If there is a risk there at all, and Prof Walker-Smith clearly believes that there is, it cannot be a very large one.

I say he believes there is a risk because, in his letter, he also calls for further research into Dr Wakefield's claims. He says there is now a "high priority" to conduct scientific studies to ascertain "whether there are factors that place a very small but important group of children at risk".

In the current fevered climate, I fear that, no matter how small that group of children is, or how small the risk, it will not be small enough to reassure most parents, even though it has reassured Prof Walker-Smith enough to opt for the triple vaccine for his own family.