Wakefield and his colleagues have continued to publish papers, keeping the controversy alive; though it appears that no researchers have been able to reproduce the findings of the first paper. Wakefield is about to be charged with serious professional misconduct by the General Medical Council; charges will include accusations of “inadequately founded” research, “improper funding” and conducting “unnecessary and invasive investigations” on children.

Meanwhile, more than 500m doses of MMR vaccine have been used worldwide. The World Health Organisation says the vaccine has an outstanding safety record. A major review published last year of 31 studies of MMR concluded that there were no credible grounds for questioning the jab’s safety. There exists no public data on the effectiveness of the single vaccine.

And yet here we are in the middle of a measles outbreak, with figures for the disease the highest for two decades. There have also been a significant number of fatalities in people who have developed measles, especially in America, and especially among the 18-22 age group.

In an outbreak of measles in Japan that was associated with the single vaccine — which some people apparently think preferable to giving measles, mumps and rubella all in one go but leaves children dangerously exposed in the time between jabs — there were 20 deaths.

And worldwide, it appears that more children have side-effects following the single vaccine. I could go on and on — and tell you, for instance, that all paediatricians at the Portland hospital in London have given their children the combined vaccine — but I think you probably get my drift.

I do hope you’re impressed with my MMR knowledge. I acquired it because my youngest child has a compromised immune system, and I wanted to make sure that we weren’t dicing with danger when it was time for her immunisations. I live in a part of London where hardly anyone “believes” in the triple vaccine, so off I trotted to our GP, to find out about single jabs. I asked my daughter’s immunologist at Great Ormond Street what she thought as well, for good measure.

The replies were utterly conclusive: don’t be an imbecile, and for heaven’s sake give her the triple vaccine. Our (private) GP doesn’t actually offer single vaccines, not least because tormenting a baby with six injections as opposed to two (with six lots of possibly feverish reactions), when there is no evidence that two don’t do the job beautifully, seems wilfully perverse.

Measles isn’t one of those piddly little childhood diseases like chickenpox. In its most benign form it is mild, but complications are common. They include a severe cough and breathing difficulties, pneumonia and eye infections; these most usually occur in the one-to-four age group.

One in a thousand people with measles get encephalitis (swelling of the brain). Of these, a quarter suffer permanent brain damage. In the 1940s and 1950s, 500 children a year died from measles. The death in April of a 13-year-old boy was the first in the UK for 14 years. If people don’t get a grip, it won’t be the last.

And mumps and rubella aren’t exactly a breeze, either: the former can lead to sterility in boys and the latter, if contracted by a pregnant woman, can cause blindness and deformities in her unborn child.

What drives me especially mad about this subject is the deranged notion held by some parents — usually middle-class — that there is somehow a gigantic medical conspiracy to keep them in the dark about MMR. “There’s something we’re not being told,” they mutter ominously, as though the medical profession collectively gets its kicks by making people ill and deliberately triggering autism in their children.

This is complete lunacy, obviously, and yet it is a viewpoint that not only persists but seems to gain credence by the day. Being opposed to the triple vaccine now goes hand in hand with a liking for yoga and a preference for organic food.

The father of a child who wasn’t given the triple jab and subsequently developed measles proudly told a broadsheet last week: “He had a very mild form of measles, which I attribute to his strong immune system.” The smuggery of this remark makes me practically levitate with rage.

There are tens of thousands of children who don’t have a strong immune system. There are children who barely have an immune system at all, and the chances are they go to the same school or nursery as children that are more fortunate.

If stupid, selfish, irresponsible parents refuse to vaccinate their children — and in my corner of north London, not being vaccinated is almost the norm rather than the exception — and those children come into contact with babies or young children who aren’t yet old or well enough to have had their MMR, they are spreading disease and illness, with the complicit blessing of their parents.

If I were a politician, instead of mimsying about trying to score points and banging on pathetically about Leo Blair, I would come down on these parents like a ton of bricks. They base their lemming-like decisions on nursery-gate gossip and half-understood hearsay, rather than on a single iota of hard evidence. And, worse than that, they show blithe disregard for any children other than their own.

• Tonight’s Panorama, The Right Time for a Baby, is presented by Kate Silverton, a 35-year-old BBC journalist. Writing in the Daily Mail last week she said that a year ago her gynaecologist told her: “You owe it to society to have children — not just you, but every educated woman in her thirties. The problem is that all you bright, professional women think you can plan your fertility with the same skill as you plan your career. And you cannot.”

  Silverton was, she writes, “horrified” by these words and by the “politically incorrect” sentiments behind them. On reflection, though, and after having investigated the subject of delayed parenthood for this edition of Panorama, she believes he was right.

  What I don’t understand about this subject is why anyone should be surprised by the notion that having a baby late in life is trickier than having one earlier. Silverton is an intelligent, educated woman, whose school curriculum presumably covered human reproduction, and yet professes herself astonished by her findings and by her change of heart.

  Why? How? And does it mean that the majority of women now seriously believe that birth begins at 40? Have they all gone mad?

  india.knight@sunday-times.co.uk

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