MMR vaccine: Encyclopedia II - MMR vaccine - The MMR controversy

MMR vaccine - The MMR controversy

Controversy has arisen regarding the efficacy of the MMR vaccine, because some scientists and parents contend that the vaccine might be linked to the development of a number of conditions, such as autism, bowel disorders such as Crohn's disease, and the brain disorder Creutzfeldt-Jakob disease (CJD).

During the 1980s and 1990s, a number of lawsuits were brought in the United States against manufacturers of vaccines, alleging the vaccines had caused a variety of physical and mental disorders in children. While these were inconclusive, they did lead to a massive jump in the costs of the MMR vaccine, as pharmaceutical companies sought to cover potential liabilities by lobbying for legislative protection. By 1993, Merck KGaA had become the only company willing to sell MMR vaccines in the United States and the United Kingdom. Two other MMR vaccines were withdrawn in the UK in 1992 on safety grounds arising from the strain of mumps component.

In September 1995, the Legal Aid Board in the UK granted a number of families financial assistance to pursue legal claims against the state health authorities and the vaccine's manufacturers, claiming that their children were killed or seriously injured by the MMR vaccine. A pressure group called JABS (Justice, Awareness, Basic Support) was established to represent families with children who, their parents said, were "vaccine-damaged."

In 1996, in New Zealand claims by an academic from Melbourne University that MMR contained a human blood product, serum albumin, and could therefore spread CJD spread anxiety. This did not last, since serum albumin was demonstrably not an ingredient of the MMR vaccine.

MMR vaccine - Dr. Andrew Wakefield's report

In February 1998, a group led by Dr. Andrew Wakefield published a paper (which later was subject to a qualified retraction by co-authors; see below), Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children in the respected medical journal The Lancet. The report analysed the cases of twelve autistic children admitted to the Royal Free Hospital in north London in 1996-1997, described a collection of bowel symptoms, which Wakefield asserted was evidence of a possible novel syndrome, which he would later call autistic enterocolitis, and recommended further study into the possible link between the condition and environmental triggers, i.e., the MMR vaccine. The paper proposed links between gastrointestinal symptoms and developmental disorders in twelve children that were alleged to be associated in time with MMR vaccination. No conclusions about causal links, such as that MMR could lead to autism, were reached. However, at a press conference before the paper's publication, Dr Wakefield said that he thought it prudent to use single vaccines instead of the MMR triple vaccine until this could be ruled out as an environmental trigger, given that parents of eight of the twelve children studied were said to have blamed the MMR vaccine, saying that symptoms of autism had set in within days of vaccination at approximately 14 months. He declared, "I can't support the continued use of these three vaccines given in combination until this issue has been resolved." In a video news release, issued by the hospital to broadcasters in advance of the press conference, he called for MMR to be "suspended in favour of the single vaccines." [2]

The paper, press conference and video sparked a major health scare in the United Kingdom. The subsequent debate became polarised. Wakefield's research was misused by parties from both sides of the argument. He became subject to attacks, his critics savaging both the validity and the ethics of the research. The UK government and medical authorities, such as the National Health Service (NHS), stressed extensive epidemiological evidence that failed to show any connection between MMR and developmental disorders. These denials were disbelieved by some parents, not least because previous government pronouncements on safety had been widely discredited, such as in the 'Mad Cow' (BSE) affair. The government was also alleged to be unwilling to support the use of separate vaccines because the NHS could not afford them. As a result, the takeup of MMR dropped sharply, from 92% in 1996 to 84% in 2002. In some parts of London, it was said to be as low as 60% - far below the rate thought to be needed to avoid an epidemic of measles. Although an epidemic has not yet occurred, measles rates have risen and doctors have warned of the likelihood of a future epidemic, because of the failure of the protection offered by herd immunity.

A factor in the controversy is that only the combined vaccine is available through the UK National Health Service; those who do not wish to have it given to their children must either have the separate vaccines given privately, or not vaccinate their children at all. The Prime Minister, Tony Blair, has refused to state whether his son Leo has received the MMR vaccine, but has strongly supported the vaccine in public. The Chancellor, Gordon Brown, has also been asked and refused to say whether his son has received the MMR. [3]

The great majority of doctors prefer to administer the combined vaccine rather than the separate ones, as it is less distressing to the child, and parents are more likely to attend for one vaccination than for three.

Epidemiologic research on hundreds of thousands of children in numerous studies continues to show no link between MMR and autism. Critics of these epidemiology studies, such as retired British clinician John Walker-Smith, although a supporter of the triple vaccine, have pointed out that epidemiology is a 'blunt tool' and may miss causal relationships. [4] For example, it can be difficult to find two populations of sufficient size which differ only in whether they were vaccinated.

Dr. Wakefield left his job at the Royal Free Hospital in 2001. His continued research includes involvement in scientific collaborations in the U.S and Europe, and a report on possible immunologic, metabolic, and pathologic changes occurring in what Wakefield has called "autistic enterocolitis", links between intestinal disease and neurologic disorders in children, and the potential relationship of these disorders to environmental causes, such as vaccines. [5]

In February 2004, it emerged that when Wakefield had published The Lancet report, £55,000 funding was received by the Royal Free Hospital from lawyers seeking evidence of any link between autism and the MMR vaccine [6]. According to a Sunday Times investigation, several of the parents quoted as saying that MMR had damaged their children were also litigants. Although Wakefield maintains the funding was properly disclosed from the outset, allegations have been made that the funding was not revealed to either The Lancet or Wakefield's co-researchers. On February 20, 2005, The Lancet said it should have never published Wakefield's study, which was "flawed" because Dr Wakefield had "a fatal conflict of interest." Several of Dr. Wakefield's co-researchers also strongly criticised the lack of disclosure. [7] The General Medical Council, which is responsible for licensing doctors and Supervising Medical Ethics in the UK is reported to be investigating the affair. [8].

The 'investigation' which led to 10 of the 13 authors' of the 1998 Lancet paper formally retracting the claim of having found a possible link between MMR and autism was carried out by Brian Deer for The Sunday Times of London. [9] Deer continued his investigation in a British television documentary, MMR: What They Didn't Tell You, broadcast on November 18, 2004. This alleged that Wakefield had applied for patents on a rival vaccine to MMR, and knew of test results from his own laboratory at the Royal Free hospital that contradicted his claims. [10]

Adapted from the Wikipedia article "The MMR controversy", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki