What is it about MMR? Another survey, this time by the Today programme on Radio 4, has once again shown widespread public alarm about the triple vaccine against measles, mumps and rubella (german measles). Two-thirds of those polled, according to the BBC, think that parents should have the choice of three single vaccines for their children, if that is what they want.
Extraordinary, is it not, that Britain's middle classes have whipped themselves into such a frenzy over MMR? Given all the threats to life and limb to which children are exposed tobacco and roads are the two that top my list it is remarkable that parents are prepared to devote so much time to minimising what is already an infinitesimally small risk from a single childhood vaccination. If they devoted half as much energy to stopping smoking and slowing traffic, think how much genuinely safer for children this country would be.
But I digress. For the real problem here is that the arguments against MMR are completely wrongheaded and, frankly, daft. Their effect is to increase the risk, both to the individual child and to the wider community. It is not too strong to say that the continued campaign against MMR threatens a public health disaster.
Let us take the issue of choice first, for this is what most exercises parents involved in this debate. Whatever the facts, it is said, it must be just that parents have the right to give their children them singly, even if ultimately that option is proved to be less safe. Parental choice is sacrosanct.
It is this, superficially laudable, sentiment which presumably explains the Today poll finding. But the argument is flawed. It is astonishing how many intelligent parents, who have spent hours carefully weighing the evidence for and against MMR, have neglected to do the same for the single vaccines that they favour.
They blithely assume that the single vaccines are the same as the component parts of the triple MMR vaccine, and that by having them singly they can avoid the theoretical "shock" (for which there is no evidence) all three at once delivers to a child's developing immune system.
Unfortunately, the single vaccines are not the same. No safety review has ever been conducted of the single measles vaccine, which is not licensed in the UK. Many parents who have paid for the single mumps vaccine privately will have received the Urabe or Rubini strains imported from the continent. The Urabe strain, which was included in the early version of the MMR vaccine, was withdrawn after it was linked with cases of aseptic meningitis. It was replaced, as a constituent of MMR, by the Jeryl Lynn strain in 1992. The Rubini strain has not been licensed in the UK since it's effective in only 12 per cent of children.
Even if the single vaccines were equivalent, which they are not, giving three at intervals is inherently less safe than giving one. During the intervals between the separate vaccines, the child remains exposed to the risk of catching the illnesses against which it has not yet been vaccinated. Furthermore, some parents will inevitably fail to return for the second and third jabs, reducing the level of cover in the community. In Japan, the only country where single vaccines are recommended, regular measles outbreaks have occurred since the early 1990s, and between 1992 and 1997 there were 79 deaths.
MMR is much more widely used than the single vaccines and has consequently been more intensively studied. At least 500 million doses have been given worldwide, and continuous post-marketing surveillance has not revealed any significant risk. Four specific studies set up to examine the claims of a link with autism and bowel disease have failed to confirm them. Although cases of autism have risen dramatically in the last decade this is thought to be largely, if not wholly, because it is better detected.
This is still not enough to satisfy many parents. They are alarmed by the continuing publicity around MMR and they insist they must have the right to choose, even if that means making the wrong choice.
But this is a libertarian step too far and one that threatens the public good. We already accept restrictions on our right to choose, in the interests of protecting both personal and public safety. The clearest example is the ban on drink-driving. We accept it because we know the terrible consequences of the alternative shattered bones and smashed lives. Nor is this only about the protection of others. Seatbelts and motorcycle helmets are also compulsory the state's attempt to protect us from ourselves.
A large part of the reason why the campaign against MMR has been able to gain momentum is that there is no equivalent of the roadside carnage that reminds us regularly of the danger of drink-driving. It is precisely because of the success of MMR that we no longer see in Britain the consequences of the diseases against which it protects.
Yet measles is a killer. Though most adults over 40 will remember it as a mild fever accompanied by a rash, it can lead to serious complications including encephalitis (swelling of the brain) and death. Mumps can cause sterility, and rubella can result in birth defects if passed on to pregnant women. There have been no measles deaths in the UK since 1990, but in 1988, the year MMR was introduced, there were 76,000 casesand 16 deaths.
There is one other argument that the anti-MMR lobby trots out. It is that confidence in MMR thanks largely to their efforts is falling. It must be better to allow parents single vaccines than to risk children having none.
It is true that the current position is bad, but it is not yet a disaster. Nationally, vaccination rates have dropped from 93 per cent to 88 per cent (and lower in some areas). During the whooping cough vaccine scare of the 1970s, vaccination rates fell below 50 per cent (and it was followed by a series of epidemics). We are teetering on the edge of the abyss but it is not yet time to jump into it. Unless vaccination rates fall dramatically, the Government must hold firm and work to rebuild confidence in MMR.
The worst feature of this saga is what it tells us about the nation's loss of confidence in science. The best scientific research shows that MMR is safe. That is what must govern Britain's policy. If ministers yield to the mob, even one composed of the chattering classes, it will be a black day for science, for health and for children.