MMR vaccine

The MMR vaccine is a mixture of live but attenuatedviruses, administered via injection for immunizationagainst measles, mumpsand rubella. It is generally administered to children around the age of one year, with a booster dose before starting school (i.e. age 4/5). It is widely used around the world; since introduction of its earliest versions in the 1970s, over 500 million doses have been used in over 60 countries. As with all vaccinations, long-term effects and efficacyare subject to continuing study.

According to standardized adverse effectreporting, those receiving the vaccine have experienced a number of side effects: a rash or slight fever for a few days, one to two weeks after receiving the vaccine, occasionally accompanied by a mild swelling of the salivary glands and some aching or swelling of the joints, respectively from the measles, mumps and rubella components, which have differing incubationperiods. These effects are usually mild and temporary, vanishing within a few days. There are rare reports of more serious reactions — only about one in every 100,000 vaccinations is reported to have resulted in a severe allergic reaction.

Epidemiology

Before the widespread use of a vaccine against measles, its incidence was so high that patients born before 1949are assumed to have had measles. Today, because of vaccination, the incidence of measles has fallen to less than one percent of people under the age of 30 in countries with routine childhood vaccination. Measles has a significant complication rate, which includes pneumonitisand encephalitis.

Studies, such as a Centers for Disease Control(CDC) report on the effect of vaccination against measles in Africabetween 1996-2002, have shown that vaccination markedly reduces the mortality rate due to measles.[1]

Mumps is another viraldiseaseof childhood that was once very common. A known but relatively rare complication of mumps is sterilityin males.

Rubella, otherwise known as German measles, was also very common before the advent of widespread vaccination. The major risk of rubella is if a pregnantwoman is infected, her baby may contract congenital rubellafrom her, which can cause significant congenitaldefects.

All three diseases are highly contagious.

The MMR vaccine was designed to be a trivalent single-shot vaccine that protects against all three viral diseases. Significant reduction in incidence, and therefore complications of the three diseases above, has been attributed to widespread population vaccination with MMR.

While there are known but rare side effects from using the MMR vaccine, in the public health perspective the overall benefit to the population is vastly in favour of continued vaccination.

An MMR controversy?

(also see: Vaccine controversy)

Efforts to represent a controversy as existing around MMR have used a variety of suggested associations with illnesses. Some are risible (see below) and as each is demonstrated to be unfounded another is brought forward. This follows a pattern familiarsince Smallpoxwas solved.

During the 1980sand 1990s, a number of lawsuits were brought in the United Statesagainst manufacturers of vaccines, alleging the vaccines had caused a variety of physical and mental disordersin 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 lobbyingfor legislative protection. By 1993, Merck KGaAhad 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 1992on 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. Later, the case was recognised to be without foundation or hope, and legal aid terminated. A pressure groupcalled JABS (Justice, Awareness, Basic Support) was established to represent families with children who, their parents said, were "vaccine-damaged."

In 1996, in New Zealandclaims by an academic from Melbourne Universitythat 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.

Dr. Andrew Wakefield's report

1998 Lancet paper

In February 1998, a group led by Dr. Andrew Wakefieldpublished 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 childrenin the respected medical journal The Lancet. The report analysed the cases of twelve autistic children admitted to the Royal Free Hospital in north Londonin 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]

Controversy following publication of report

The paper, press conference and video sparked a major healthscare 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 epidemiologicalevidence 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 safetyhad 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 1996to 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 Leohas 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]

Conflict of interest allegations

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].

Retraction of Lancet paper

The investigation which led to 10 of the 13 authors of the 1998Lancet paper formally retracting the claim of having found a possible link between MMR and autism was carried out by Brian Deerfor The Sunday Timesof London. [9] Deer continued his investigation in a British television documentary, MMR: What They Didn't Tell You, broadcast on November 182004. 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]

Recent studies

Epidemiological research continues to show a dramatic increase in the incidence of autism, but whether the increase is real, rather than an artifact of diagnosis and reporting, is unknown, and no causal connection has been demonstrated to the MMR vaccine. Since Wakefield's paper, there has been substantial clinical research investigating his claim to have found measles virus located in the gut of proportion of children, much of which has been financed by litigation, with the results not reported on legal grounds.

• In October 2004, the Journal of American Physicians and Surgeons, formerly the Medical Sentinel, magazine of the conservative Association of American Physicians and Surgeons, published a report by Wakefield supporters questioning the validity of one of the major epidemiological studies into MMR and concluded that "Developing safer vaccination strategies and supporting further investigation of the hypothesized link between the MMR vaccine and autism should have a high priority." [11]
• In October 2004 a review, financed by the European Union, was published in the October 2004 edition of Vaccine [12]that assessed the evidence given in 120 other studies and considered unintended effects of the MMR vaccine. The authors concluded that
  • the vaccine is associated with some positive and negative side effects,
  • it was 'unlikely' that there was a connection between MMR and autism, and
  • 'The design and reporting of safety outcomes in MMR vaccine studies ... are largely inadequate'.
• In January 2005, intensive research in a single county in Minnesota reported an eightfold increase in the incidence of autism over a period beginning in the early eighties and ending in the late nineties but found no evidence of a link with MMR. The authors of the research suggested that the increase in autism was due to an increased awareness of the disorder, a growth in services, and changing definitions. [13]
• In March 2005 a study of over 30,000 children born in one district of Yokohamaconcluded that the rate of autism in children continued to rise (from 46-86 cases per 10,000 children, to 97-161/10,000) after the use of the MMR vaccine was discontinued in Japan in April 1993. The authors' conclusion was: "The significance of this finding is that MMR vaccination is most unlikely to be a main cause of ASD, that it cannot explain the rise over time in the incidence of ASD, and that withdrawal of MMR in countries where it is still being used cannot be expected to lead to a reduction in the incidence of ASD." [14]Reference: Journal of Child Psychology and Psychiatry (DOI: 10.1111.j.1469-7610.2005.01425.x) cited in New Scientist. [15]Dr. Wakefield contends the pattern of autism rates revealed by the data support his hypothesis. [16]His views, however, have found little support [17].
• In October 2005, the Cochrane Library published a review of 31 scientific studies, and concluded that "there was no credible evidence behind claims of harm from the MMR vaccination". [18]However the authors of the report stated that "The design and reporting of safety outcomes in MMR vaccine studies, both pre- and post-marketing, are largely inadequate."[19]Cochrane, based in Oxford, England, is widely regarded by scientists as the most authoritative independent reviewer of medical literature, and the custodian of "evidence-based medicine".

References

• BMJJournals.com (pdf)- 'Measles, mumps, and rubella vaccination and bowel problems or developmental regression in children with autism: population', Brent Taylor, Elizabeth Miller, Raghu lingam, Nick Andrews, Andrea Simmons and Julia Stowe, British Medical Journal, Vol 324, pp 393-396, February 16, 2002

• BMJJournals.com- 'Rapid Responses to: Increase in autism due to change in definition, not MMR vaccine' British Medical Journal (opinions exchanged at BMJ website)

External links

• BBC.co.uk- 'Does the MMR Jab Cause Autism?' (TV programme transcript), BBC(May 29, 2005)
• BMJJournals.com- 'Authors reject interpretation linking autism and MMR vaccine', Susan Mayor, BMJ, vol 328, p 602 (March 13, 2004)
• BMJJournals.com- 'Unreliability of Scientific Papers as Evidence', Clifford G. Miller, BMJ rapid response (March 12, 2004)
• BrianDeer.com- 'the Lancetscandal' ('investigation' of MMR affair), Brian Deer
• Guardian.co.uk- 'At last - the end of the MMR myth: Dr Simon Atkins on why it's safe to give jabs', The Guardian (October 20, 2005)
• Jabs.org.uk- 'The Support Group for Vaccine-Damaged Children' (UK advocacy group)
• MedicalNewsToday.com- 'Cochrane Librarypublishes the most thorough survey of MMR vaccination data', Medical News Today
• Medinfo.co.uk- 'Medical Information for Patients: MMR Vaccination'
• MMRTheFacts.NHS.uk- 'MMR the Facts', United Kingdom National Health Service(government website)
• MMRTheQuestions.com- 'MMR: The Questions' (includes Andrew Wakefield's response to Brian Deer's 'investigation')
• RedFlagsDaily.com- 'Alive and Well: The MMR-Autism Connection', F. Edward Yazbak, MD, FAAP, Red Flags (October 29, 2005)
• Scotsman.com- 'Family sues over alleged MMR link to autism: A Scots family will launch a multi-million-pound lawsuit at the High Court in London today, claiming the MMR vaccine was responsible for causing autism in their child', Tanya Thompson, The Scotsman (January 24, 2006)
• SpikedOnline.com- 'How did the doctor get away with it? Brian Deer's investigative documentary on MMR went some way towards redeeming the reputation of the media', Dr. Michael Fitzpatrick (November 19, 2004)

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It uses material from the http://en.wikipedia.org/wiki/MMR+vaccine Wikipedia article MMR vaccine.