Many worried parents continue to withhold MMR vaccination from their children. Dick Ahlstrom examines the latest MMR/autism research
The latest study discounting the presumed link between the MMR vaccine and the incidence of autism will not bring an end to the ongoing safety debate. Many parents of small children will continue to err on what they believe to be the side of caution when it comes to the protection of their little ones.
Refusal to give the MMR vaccine, which protects against measles, mumps and rubella, puts these same small children at even greater risk of injury and death. Measles kills about one in 1,500 children who contract it and a much greater number develop illnesses that cause brain damage and deafness.
The debate about the three-in-one isn't all about measles. The MMR also protects against rubella and shunning the jab, which protects against German measles, increases the potential exposure of pregnant women to this dangerous virus. Exposure represents yet another risk with brain-damaged newborns the frequent result.
Although German measles generally causes only minor illness in children, it can cause devastating damage to the foetuses of pregnant women. A pool of unvaccinated children helps this virus to spread easily through play groups, schools and creches, places where pregnant women dropping-off older children can contract it with terrible consequences.
Many parents are willing to risk a child's exposure to the wild measles virus rather than voluntarily subject their children to the MMR because of fears of autism. This is a dangerous choice.
The camps on either side of the MMR debate always dispute figures and relative risks associated with illnesses linked to childhood vaccinations. There is a stark difference between the two positions, however, in terms of risk to children.
A frequently quoted figure for death caused by wild measles virus is one in 1,500. Risk of other damage such as deafness shortens the odds considerably.
The pro-vaccination side cite statistics that suggest that the risk of autism, Crohn's disease or other damage is about one in a million and even lower. Anti-vaccination people argue that the autism risk is much greater, with some claiming a risk of one in 100,000 and even one in 10,000. Yet this still makes vaccination a safer option than the risks of your child encountering wild measles virus if the conservative one in 1,500 figure is accepted. Which odds would you back if you were a gambler? It is moot to argue this is gambling with a child's health because they face risks either way.
And the dangers of exposure are very real indeed given the abject failure of successive MMR vaccination campaigns promoted by this and previous governments.
The MMR vaccine arrived in the late 1980s but the first strong study backing the link didn't arise until work done at the Royal Free Hospital in London by Dr Andrew Wakefield in 1998. He reported in the Lancet on 12 children believed to have autism and related disorders as a result of the MMR.
This research sparked a quick response from health officials around the world, including UK and Swedish studies, a very large study done in Finland and work in the US. Virtually all of these involved much larger numbers of children and ruled out definitive links between autism, bowel disorders and the MMR.
Once the doubts were sown however, they took root and people began to shun the three-in-one vaccination.
More recent anti-vaccination claims talk about "new variant" autism. The Royal Free Hospital study released yesterday negates claims for an undefined new variant version of the disease.
The claims and counter-claims have only served to muddy the waters and have made parents more reluctant to have their children vaccinated. It remains to be seen whether this is wise or foolhardy counsel.