Lack of confidence in the MMR vaccine affects immunization rates

LONDON — Using vaccines outside their licensed indications could put the lives of children in danger and trigger new epidemics of diseases that are virtually eradicated in the UK, immunization experts warned last week.The potential new crisis surrounds the use — or lack of — the triple measles, mumps and rubella vaccine (MMR) introduced in the UK in 1988. In the last three years, uptake of the vaccine has dropped from 93% of all children to 86%, largely because of publicity surrounding research published by Andrew Wakefield and colleagues at the Inflammatory Bowel Disease Study Group (IBDSG), London, suggesting a link between the vaccine and serious conditions including inflammatory bowel disease and autism.In the 1990s the Group, which is based at the Departments of Medicine and Histopathology, Royal Free Hospital in London, suggested firstly that measles disease and, later on, that measles vaccination was linked to inflammatory bowel disease in adults. The research has been widely criticised and further work by others in the IBDSG and elsewhere has failed to replicate the original findings.But it was in 1998 when work published by Wakefield and colleagues set alarm bells ringing in the minds of the public and subsequently became the real nail in the coffin of the UK's MMR vaccination programme. The paper in the Lancet described 12 children with bowel symptoms and autism-like developmental problems. Although the researchers admitted they could not substantiate a link between MMR vaccination and the symptoms, parents of eight of the children said that the symptoms began soon after immunization.This supposition, plus a widely quoted Wakefield saying the "immune system overload" was to blame, was enough to create near-hysteria in the press and a widespread loss of confidence in UK government vaccination experts and in one of the most extensively tested vaccines currently available. This was despite the fact that since the 1998 study no research team had been able to find an association between the MMR vaccine, autism and bowel disease.For some UK parents, it has become a mission to track down doctors willing to give single vaccines for measles, mumps and rubella — even leaving the country if they have to — and invent their own vaccination schedules to deliver a more drawn-out process to get their children immunized.It is against this background that experts in child health have now hit back, laying bare the facts that single vaccines have not been proven safe or effective. "People are being consumed by DIY vaccination policies and we felt it was appropriate to review all the evidence and highlight the issues of using single vaccines," said Helen Bedford, senior research fellow at the Department of Paediatric Epidemiology and Biostatistics, Institute of Child Health, London, who co-wrote a review article in October 2001 Archives of Disease in Childhood (Arch Dis Child 2001, 85:271-274). "People are taking vaccines and chucking them at young children despite the fact that we have no safety evidence to support using the single vaccines in this age group."There is no country in the world where single vaccines for measles, mumps and rubella are recommended in the place of the combined MMR vaccine. Some of the single mumps vaccines are not licensed, warned the authors, and at least one is ineffective while another increases slightly the risk of meningitis.According to Bedford, the 93% uptake of MMR in the early '90s was close enough to the WHO's target of 95% to keep these diseases at bay and figures from the Public Health Laboratory Service (PHLS) testify to the vaccine's success. "Notifications of measles are now in the 100s, mumps is rare and rubella is now an uncommon event. We had it licked," said Bedford.But even with just a minority of parents turning their backs on MMR the whole strategy to eradicate these diseases from the UK is in danger of collapsing, she added. "If parents follow Wakefield's advise it means six injections and trips to the clinic instead of two for MMR and many parents will simply drop out at some stage," said Bedford. "It could have a disastrous effect on the control of these diseases."Measles will be the first disease to re-emerge in epidemic proportions, she predicted, with rubella following later.In a strongly worded commentary Archives of Disease in Childhood review Elizabeth Miller, from the PHLS, partly blamed the Lancet for failing "to identify basic flaws in the design and evolution" of Wakefield's studies. "Publication of commentaries speculating on the validity of the findings and the possible biases cannot redress the balance," she warned.

Lack of confidence in the MMR vaccine affects immunization rates

report into a possible link between MMR and autism has resulted in fewer children being immunized.

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