MMR: The debate that won't go away
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|Tue, 05-27-2008 - 9:48am|
MMR: The debate that won't go away
Last Updated: 12:01am BST 26/05/2008
It seemed the MMR controversy had been resolved, but does new research point to another possible connection between autism and vaccinations? Cassandra Jardine reports
Four years ago, it seemed as if the agonising over autism and the measles, mumps and rubella (MMR) triple vaccine had finally been consigned to history. Several large-scale epidemiological studies concluded there was no evidence of a link between the two.
Taking just one of these studies - involving 4,500 children in Denmark - Sir David King, chief scientific adviser to the Government until the end of 2007, said: "If anything, there was more autism found among the children who weren't vaccinated."
Parents who had claimed that their children had regressed mentally and physically following the MMR vaccination were told it was probably a coincidence. Meanwhile, Dr Andrew Wakefield, the gastroenterologist whose research had triggered the scare, with a study in 1998 of 12 such cases, is currently defending himself in front of the General Medical Council against charges of gross professional misconduct.
So how is it now that the debate has been reignited in the US, with growing concern that an apparent increase in the number of children with autism may have an environmental cause (including MMR and other childhood vaccinations)?
All three presidential candidates have referred to what Republican Senator John McCain calls the "autism epidemic", pledging substantial sums of money for research.
Then, earlier this month, Dr Bernardine Healy, former head of the National Institutes of Health, America's medical research agency, told CBS News: "I think that the public health officials have been too quick to dismiss the hypothesis as irrational." She called for detailed studies of children whose parents believe they have been affected. "I have not seen major studies that focus on 300 kids who got autistic symptoms within a period of a few weeks of the vaccines," she said.
Healy's comments are significant because she's the first figure from the mainstream medical establishment not to dismiss the link.
Next month David Kirby, author of the award-winning book Evidence of Harm, will be in London giving a public lecture and addressing the House of Lords about the causes of regressive autism (as opposed to classic autism, which does not involve a sudden loss of speech and other functions).
The focus of his attention is not MMR but thiomersal, a preservative containing mercury (a known neurotoxin) that is used in some vaccines, including those for flu. (The Department of Health is keen to stress that no children's vaccine in this country has contained thiomersal for the past four years, and when it was formerly used in childhood vaccines it was at levels that were lower than those in the US.)
"A convergence of events," Kirby says, "has highlighted the importance of research, treatment and identifying the minority of children who may be susceptible to vaccine damage."
Chief among these convergent events is the case of Hannah Poling, the nine-year-old daughter of neurologist Jon Poling, from Georgia. In July 2000, aged 19 months, she received five different vaccinations, against a total of nine diseases, in one day. Her mother Terry says that when she entered the surgery, she was a bright - even precocious - child. Within 48 hours, she had stopped eating, ceased to respond to speech and become prone to episodes of screaming and fever.
Hannah Poling's case is part of the Omnibus Autism Proceeding - 5,000 cases of regressive autism being looked at by the US Vaccines Court, a body funded by a 75 cent levy on every vaccine given in the US. In February, the US government agreed compensation for her disabilities, having conceded, out of court, that her condition had been "significantly aggravated" by vaccination.
Initially, her case didn't appear to be of widespread significance because she was found to have a dysfunction of the mitochondria, the "batteries" in our cells that produce energy essential for normal functioning. This abnormality made her an unsuitable test case in any legal proceedings.
But then the next child under consideration as a test case was found to have a similar weakness, raising the possibility that a small minority of children may, because of a genetic predisposition, be more susceptible to the damaging side-effects of vaccination.
"It now looks as if 20 per cent of children with regressive autism may have this weakness; some are saying 65 per cent," says Kirby. "The cause of this weakness could be genetic or environmental."
The last point is crucial. Jon Poling, Hannah's father, believes two triggers are needed before a child becomes severely ill: possibly, an early vaccination which might compromise a child's metabolic system, then a later one which results in symptoms. There are various theories why this might be so. According to David Kirby, even trace elements of mercury and aluminium (also used in vaccines) might damage the mitochondria and could be passed from mother to foetus.
The actor Jim Carrey and his wife Jenny McCarthy believe that McCarthy's son, Evan, was "vaccine-damaged" four years ago, aged two. "In the Eighties. children received only 10 vaccines by age five, whereas today they are given 36 immunisations, most of them by age two," says McCarthy. "With billions of pharmaceutical dollars, could it be possible that the vaccine programme is becoming more of a profit engine then a means of prevention?" On June 4 they will be leading a march in Washington DC, waving banners saying "Too many. Too soon."
To date there has been no successful legal challenge to MMR in the UK. There is a Vaccine Damage Payments Unit which was set up in 1979, following concerns that the whooping cough (pertussis) vaccine could cause brain damage (the vaccine has since been changed).
However, compensation is capped at £120,000 (including legal costs) and disability thresholds are high. Only two out of 53 claims were successful in the year to April 2008 - neither of them for autism.
"Under the US system, a person may receive an award if they can prove the vaccine caused an existing condition to get worse," explains a spokesperson for the Department of Work and Pensions. "This provision doesn't exist in the UK system, where… payments are made when it can be shown that it was more probable than not that someone became severely disabled as a result of vaccination."
In the civil courts, more than 1,000 cases were being prepared for a group MMR action until, in September 2003, legal aid was withdrawn. No reason was given. Following the success of the Poling case in the US, Peter Todd of London solicitors Hodge, Jones & Allen, has 200 clients who want to reapply for legal aid. He believes vaccines could be linked to a whole range of neurological and auto-immune disorders - epilepsy, childhood diabetes, arthritis, and even attention deficit hyperactivity disorder (ADHD).
"Vaccines are designed not to infect but to stimulate the immune system into making a response, so it would not be surprising if they were implicated in auto-immune disorders," Todd says. "Even if the condition was underlying, vaccines may have materially affected its onset."
The vaccine hypothesis was bolstered recently by a five-year study in monkeys who were given the same vaccinations that American children are routinely given. Last week, Dr Laura Hewitson, a specialist in obstetrics, gynaecology and reproductive sciences at the University of Pittsburgh, told the International Meeting for Autism Research in London that in the double-blind placebo-controlled study, 13 vaccinated animals showed increased aggression, impaired cognitive skills and developmental delay. The three unvaccinated animals in the study developed normally.
"There was a significant difference between the two groups," said Hewitson. "The vaccinated group had trouble developing reflexes?… They also became more insular and more aggressive. There was an increase in aggressive behaviour after they had their MMR vaccines, and they stopped exploring their surroundings as much."
Abnormal brain activity was found in the monkeys, and higher sensitivity to a naturally occurring brain chemical linked to sleeplessness, hallucinations, lack of social skills and a high pain threshold - all symptoms found in children on the autistic spectrum. The monkeys also exhibited abnormalities of the amygdala, the part of the brain which regulates emotions.
"We can't conclude that vaccines cause autism from this study," said Hewitson, "What we can conclude is that the vaccinated monkeys showed significant negative behavioural differences before and after the MMR."
Certainly autism appears to have increased dramatically. In the early Nineties prevalence in the UK was put at four or five per 10,000. In 2006, The Lancet put it at one in 86 and, last year, Cambridge University's Autism Research Centre estimated that some 210,000 children - one in 58 - suffer from an autistic spectrum disorder.
Few people believe that vaccination programmes should cease. The vast majority of children benefit from being protected against a range of diseases, but there are concerns that some may be paying a high price for immunity. Already there is a sense of panic coming from Government circles about the future of the immunisation programme.
Earlier this month Labour MP, Mary Creagh, proposed that children should not be allowed to attend school if they haven't had all their jabs; last week it emerged that doctors in the south-east of England were giving children two doses of MMR in a three-month interval (the usual regime is at 13 months and then aged 3) to prevent a measles outbreak spreading beyond the capital.
Of course further research is needed into the early identification of autism and its causes. However the new evidence from the US suggests that screening children for mitochondrial dysfunction (there are "markers" in the blood of affected children) may also be beneficial.
Delays in vaccinating children who display asthma, eczema, food allergies and other signs of a compromised immune system should also be considered, as well as a ban on "catching up" - children who have missed immunisation being given vaccines in a shorter time period - which could overload a young system.
Many parents believe that provision of single vaccines on the NHS would allay concern further and that some vaccinations should be scheduled for later in childhood when immune systems are stronger. The alternative may be another panic.