Those in the knowin' expect a fresh view from Boris on Thursday mornings. Well, today in The Daily Telegraph he recommends that we 'hold our horses' when it comes to all the alarmist news about a radiologist's views on the effect of mobiles - just as we should have done with the MMR panic. Dodgy mobiles? Don't hit the panic button It had to come. It couldn't last. How could we have been so naive as to think that the gods - ever jealous of mankind's technical prowess - would let us get away with an innovation as benign as the mobile phone? Like families across the country, the Johnson household has recently taken a momentous step. We gave a mobile to the 11-year-old, and it was not an easy decision to make. Look here, I said, representing the forces of inchoate conservatism, are you really sure? When I was a nipper, I said, a telephone was a semi-sacred instrument; you had to dial it by actually dialling a dial; the contraption was made of Bakelite and you never really got to have a go on it unless the grown-ups were out, and you could tip-toe softly and phone one of Rupert Murdoch's red-hot chat-lines, which had only just been invented. It never occurred to us, I said, that one day little kids would be wandering around with gizmos smaller than Mars bars that could transmit and receive music, text, film, photos, voice telephony and the latest news from Wall Street. Is it wise? Is it really suitable? I quavered. Aw shut up, they said. The next day I was deputed to buy the machine in question, and of course it is terrific. Your children can be reached wherever they are; they can phone you if they are in trouble or if you have inexplicably forgotten to pick them up from a birthday party. You can send them text messages from the Middle East, reminding them to do their piano practice, and with the fantastic system of text messaging they learn the arts of concision and clarity, not to mention spelling. In fact, the mobile has proved to be such a magnificent machine that I have long thought it was only a matter of time before some bearded genius told us that they were all really emitting gamma rays and scrambling our brains. And there he was, last night, the nation's top radiologist, breaking the bad news on the Beeb. Kiddie Mobile Panic! was the gist of it, and though, like so many of his kind, he was careful to insert all kinds of caveats into his announcement, the public was left in no doubt that it was now the opinion of some scientists that in some cases there was some risk that some unquantified use of the mobile could turn the average kid's brain into something like cauliflower cheese. So what are we supposed to do now? Do we snatch them from the satchels? Do we withdraw all mobile privileges or ration their use? Throughout the country, different households will be taking different views according to instinct and temperament. All I can say is that, in my view - and, incidentally, in the view of the learned radiologist - the jury is out, and while the jury is out, I want us all to consider another, similar case, and see what lessons may be learnt. It is now about six years since the great MMR panic began, with an article in the Lancet saying that there appeared to be a causal link between the mumps, measles and rubella vaccine and autism in small children. It was a perturbing article, by a doctor called Andrew Wakefield, and it was followed by a crescendo of alarm in the papers. Columnist after columnist jumped on the anti-MMR bandwagon, and soon the hysteria was itself epidemic. The Daily Mail raged against MMR. It was monstrous, it said, that Tony Blair would not tell the nation whether baby Leo had been given the controversial jab. Melanie Phillips said it was a national scandal, and Peter Hitchens continues to demand that the nation be given the right to inspect baby Leo's bottom for signs of the needle, though the focus of his wrath has now shifted to the Chancellor's baby. I have a feeling that even our own Alice Thomson, normally so reliable, may have taken a short ride on this frothing bandwagon, and one could see why the cause was so compelling. It must be deeply distressing, for thousands of families, to have a young child stricken by autism. That distress can only be intensified by the thought that you are yourself responsible, for allowing your small child to be given such a controversial jab. It simply can't be good for children, you think to yourself, with your own instinctive conservatism, to have so much potent medicine pumped into them at once; and if someone suggests that there is a link between this invasive treatment and autism, it is very tempting to think that they must be right. And yet - at the risk of offending the many parents for whom this is now a crusade - the evidence of such a link is just not there, and the longer the controversy goes on, the shakier Dr Wakefield's case appears to be. Before you all write me angry letters, I merely observe that the overwhelming opinion of the medical profession is that the real risk, now, is of a resurgence of measles, mumps or rubella, as the media panic has its effect, and the take-up of the vaccine falls away. Speaking personally, I will be very hacked off if I contract mumps (very nasty, apparently, for a chap of my age) while giving a speech at a primary school, just because a bunch of hysterical hacks have stampeded the population away from MMR. And exactly the same point can be made - and I hear the noise of the jury coming back in - about mobile phones. It may be that the new data is truly sinister, and that we need to jettison all the previous evidence; but that was certainly not what the scientist said. Before we all take a sledgehammer to our children's mobiles, let us calculate the rival risks. Which is more scary? The tiny chance that mobiles turn kiddies' brains to taramasalata? Or the chance that without them they could one day get into serious trouble? I know which one worries me more.