By Nick Triggle
Health reporter, BBC News
Experts say MMR is completely safe
It is the story that just rumbles on and on. Twelve years have passed since the Lancet medical journal published research linking autism with the MMR vaccine.
But, as Dr Andrew Wakefield's General Medical Council's examination of his conduct shows, the after-effects are still being felt.
His research paper, published in the Lancet medical journal in February 1998, sent shockwaves across the world of medicine and into the homes of families up and down the country.
In many ways, the study in itself was not the key to the saga.
Viewed in isolation it was - like many academic papers - cautious, saying the findings based on a study of 12 children did not prove for certain that there was an association.
Instead, it was the appearance of Dr Wakefield, then a gastroenterologist at the Royal Free Hospital in London, at a press conference which really lit the blue touch paper.
He told journalists it was a "moral issue" and he could no longer support the continued use of the three-in-one jab for measles, mumps and rubella.
"Urgent further research is needed to determine whether MMR may give rise to this complication in a small number of people," Dr Wakefield said at the time.
And so began one of the most contentious health stories of this generation.
It reached such a fever pitch in the early part of the last decade that the then Prime Minister Tony Blair even found himself having to answer queries about whether his young son, Leo, had been given the jab.
He always refused to reveal if he had, arguing it was a private family matter.
Many people understood his position, but the stance just served to heighten the confusion and hysteria over MMR.
In time, the alleged link became widely discredited - no respected research has ever supported the findings and the Lancet has subsequently said it should never have published the study.
Nonetheless, vaccination rates have still plummeted. During the mid 1990s, well over 90% of toddlers were getting the jab in the UK, but five years after the Lancet paper that had fallen below 70% in some places.
And as vaccination rates have gone down, measles rates have climbed.
In 1998, there were just 56 cases in England and Wales, but by 2008 there were 1,370. What is more, the first child death from measles for over a decade was seen in 2006.
Dr Wakefield's appearance before the GMC is born from an investigation by the Sunday Times.
In February 2004, the newspaper highlighted what it said was a series of conflicts of interest and unethical research practices.
At this point the GMC became involved, leading to the hearings which started in July 2007.
Three doctors in total faced professional misconduct charges - Dr Wakefield and two former colleagues, Professor John Walker-Smith and Professor Simon Murch.
There were another 10 authors, but they have all retracted their support for the findings.
Hours of evidence
But while the case has been one of the longest and most complex in the history of the GMC, the hearings have not focused on whether the research was right or wrong.
Instead, they have been aimed at establishing whether the research was carried out in the correct way.
The many hours of evidence sessions have focused on some of the issues originally raised by the Sunday Times.
It has been alleged children were subjected to a series of invasive tests and scans contrary to their best clinical interests.
Another key allegation has been that Dr Wakefield was being paid at the time for advising solicitors working for parents who believed their children had been harmed by MMR.
On one level the verdict is of little consequence.
Dr Wakefield no longer works or lives in the UK - he moved to the US six years ago and has set up the Thoughtful House autism centre founded on his theories.
Meanwhile, Professor Walker-Smith is retired, leaving Professor Murch as the only doctor still working in the UK out of the three.
But what the GMC's verdict might do is signal the beginning of the end of the long-running saga over MMR and autism.
While measles rates have been rising, the early signs from last year are that infection rates started to slow as confidence returns in the vaccine.
These results are being interpreted cautiously, but they give experts hope that the fallout from the 1998 research paper may - finally - be coming to an end.