A doctor found guilty of serious professional misconduct over the MMR controversy has won his High Court appeal against being struck off.
Prof John Walker-Smith carried out research with Dr Andrew Wakefield claiming there was a link between autism and the combined jab for measles, mumps and rubella.
The study caused a fall in vaccination rates, but was later discredited.
The judge quashed a GMC finding of professional misconduct.
Mr Justice Mitting called for changes in the way General Medical Council fitness to practise panel hearings are conducted in the future saying: "It would be a misfortune if this were to happen again."
Prof Walker-Smith, who retired in 2001, said: "I am extremely pleased with the outcome of my appeal.
"There has been a great burden on me and my family since the allegations were first made in 2004 and throughout the hearing that ran from 2007 to 2010. I am relieved that this matter is now over."
The former head of department at the Royal Free Hospital in north London lost his licence to practise in May 2010, along with Dr Andrew Wakefield.
A GMC panel found both guilty of misconduct over the way research into autism and bowel disease was conducted.
A third doctor, Prof Simon Murch, then a junior consultant in the department, was cleared.
The disciplinary case against the doctors centred on how they conducted their work.
The judge said the GMC panel failed to address whether Prof Walker-Smith had been doing research or simply investigating symptoms to help treat children. There had been "inadequate and superficial reasoning and, in a number of instances, a wrong conclusion", he said.
The GMC said reforms to disciplinary hearings were being considered.
Chief executive Niall Dickson added: "Today's ruling does not however reopen the debate about the MMR vaccine and autism.
"As Mr Justice Mitting observed in his judgement, 'There is now no respectable body of opinion which supports (Dr Wakefield's) hypothesis, that MMR vaccine and autism/enterocolitis are causally linked'.