Like Stuart-Smith, I had started my inquiry with the conventional assumption that the vaccine sometimes injured children. But as I saw how beliefs had generated facts, an emotion from my own childhood surfaced. It was the strange frustration of being left empty-handed when I brought snowballs into the house. There was no doubt that the parents in these cases were sincere. Margaret Best was especially decent. And yet victims vanished, again and again. It was quite some lesson in life.
As for the experts: they spoke for themselves, and sometimes they spoke under oath. Even Professor Behan, whose testimony was described as "paramount" in Dublin, was later crushed in a London trial. After his evidence was undermined last year in a case about organophosphates, he was investigated by Glasgow University, which later said: "there had been no intention to deceive".
Professor Miller, of the NCES, refused to comment, despite the seriousness of the vaccine-damage question to parents. Professor Stewart stuck to his story. "Any vaccine can be damaging, in different ways," he said. "Whooping cough vaccine is not very effective and sometimes in some children is very unsafe."
Rosemary Fox was co-operative, and agreed to an interview at her home in Shipston-on-Stour, Warwickshire. She is a big-framed woman of 70, full of energy, with the manner of a top civil servant. She was a farmer's daughter from County Tipperary: another determined Irish mother. Her daughter, Helen, had become handicapped in 1963 after a polio vaccination.
She had 600 families on her association's list, 300 of which, she said, were "active". They were currently preparing for a new offensive to increase the scale of government compensation payments. Some argued that payments should be increased to more than £1m for each child. Fox was preparing to send 150 MPs a briefing with which to lobby ministers.
We sat in her conservatory. She made a ham salad and produced a plastic bag full of yellowing cuttings, parliamentary debates, science papers and letters. She put it by her chair like a less active 70-year-old might settle down with a bundle of knitting.
We quickly passed over the usual contradiction between the written word and a parent's recollection. According to a Birmingham Post cutting in the bag from 1973, her daughter Helen had a polio jab at 7 months and "within a few days" began vomiting. But Fox told me the problem started as a coma "the day after the vaccination".
By this time, expert after expert was lining up around the world to say that they used to believe in DTP damage, but now they thought it a myth. Textbooks were being rewritten, questioning NCES, and new surveys were finding no risk.
"So how do you feel about it, 25 years later," I asked her. "You've still not been able to show a case."
"I know," she said, gloomily. "I don't know where the weakness is." She admitted that the science suggesting a link was "hopeless", but she thought that the compensation scheme showed that the link must exist. The government would not give money away if the vaccine did no harm. Since 1978, 891 awards had been made (mostly £10,000) and she had just got a letter saying that ministers were reviewing the size of future grants. That was 891 of the quarter-million British children who, for various reasons, were brain damaged in the last 25 years.
"At the end of the day," I suggested, "your belief that the vaccine causes damage is an article of faith, really."
"Maybe so," she said. "But it would be very difficult for me, after starting it off and believing it and establishing it by reference to other parents as to what their experiences are..." Her words petered out.
I said that technologies in brain scanning, biochemistry, DNA and so forth had leapt forward since her daughter was diagnosed as vaccine-damaged. Would she consider having Helen reassessed?
Fox said that she would not. "She's what 35, 36 years old. Her condition is established, if you like, how she is. I wouldn't want to know."
"But in 30 years, science has - "
"It's not worth it to go back and think: 'did you realises that such and such'."
"Right," I said.
"Then I'd start thinking: should I give back the money to the government? Why did I do this? Was I wrong? Are all these 891 people...? Do you want to have me in a mental hospital?" She laughed. "Go away."
Wilson, now 67, was not so cheerful, and after agreeing to meet me at a Great Ormond Street address, later called back and cancelled. "I really think I have nothing useful to contribute," he said.
When I phoned him at home he argued that his 36 cases delivered to the Royal Society of Medicine were only "hypothesis-generating". He said: "They were raising the issue, and I think certain things transpired from that which have been beneficial. But I'm very ready to accept that there's a downside to this whole exercise which one obviously regrets."
Although he omitted an explanation for his vanishing victims, he defended his campaign. To understand his position, he said, you would have to imagine yourself as a doctor faced by "this recurring story from parents" of children who were ill after jabs. "You are puzzled by this," he said. "You look back at some of the things that have been written. And, yes, there is evidence in the literature, case reports of children who have been very severely damaged, especially when the child seemed to be unwell at the time the immunisation was given. What do you do? Do you think 'Ah, this might rock the boat and stop the immunisations; it may cause public alarm'? What do you do?"
He acknowledged mistakes, but said it was through mistakes that scientific knowledge advanced. What came to his mind was the cliché about a teacher at the front of a lecture theatre. "There was a very wise doctor who made the introductory observations to a new batch of medical students," he said. "That in 20 years' time half of what you now learn will be proved to be wrong. But the problem is: we don't know which half."
Read the award-winning MMR-autism fraud investigation.