MMR vaccine
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The MMR vaccine is a combined vaccine for immunization against measles, mumps and rubella. It is generally administered to children around the age of 1 year, with a booster dose before starting school (i.e. age 4/5). It is widely used around the world; since its introduction in the 1970s, over 500 million doses have been used in over 60 countries. Those receiving the vaccine may experience 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. These effects are mild and temporary, vanishing within a few days. Children rarely have more serious reactions - only about one in every 100,000 vaccinations results in a severe allergic reaction. If treated quickly, the child should fully recover.
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Epidemiology
Before the widespread use of a vaccine against measles, the incidence of measles was so high that in 2004, any patient over the age of 55 is assumed to have had had measles in the past. Today, because of vaccination, the incidence of measles in countries with routine childhood vaccination has fallen to less than 1% of people under the age of 30. Measles has a significant complication rate which includes pneumonitis and encephalitis.
Studies have shown that vaccination markedly reduces the mortality rate due to measles (CDC report on effect of vaccination against measles (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5302a2.htm) in Africa between 1996-2002).
Mumps is another viral disease of childhood that used to be very common. A known but relatively rare complication of mumps is causing sterility in males.
Rubella, otherwise known as German measles was also very common before the advent of widespread immunization against it. The major risk in rubella is if a pregnant woman is infected, her baby may contract congenital rubella which can cause significant congenital defects.
All three diseases are highly contagious.
The MMR vaccine was designed to be a single-shot vaccine that protects against all three viral diseases. Significant improvements in reducing the incidence and therefore, the complications of the three diseases above has been attributed to widespread population vaccination with MMR.
Whilst 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.
The MMR controversy
Controversy has arisen because some scientists and parents claim that the vaccine may 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 that 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 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, a controversy broke out in New Zealand concerning an allegation that the MMR vaccine could spread CJD. A Melbourne University academic claimed that MMR contained a human blood product, serum albumin, and could therefore spread CJD. The controversy died down after doctors highlighted the fact that serum albumin is not an ingredient of the MMR vaccine.
Dr. Andrew Wakefield's report
In February 1998, a group led by Dr. Andrew Wakefield published a paper, Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children (http://www.ncbugs.com/From_ncbugs/ACROBATS/Wakefield98.pdf) 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. 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 that "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". [1] (http://briandeer.com/wakefield/royal-video.htm)
The press conference and video sparked a major health scare in the United Kingdom. The subsequent debate became polarised, Dr Wakefield's research was misused by parties from both sides of the argument, and he became subject to attacks, his critics savaging both the validity and the ethics of the research. The 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 assertions 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. It was also alleged that the government was 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 needed to avoid epidemics 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 on 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 [2] (http://www.informedparent.co.uk/noticeboard.html).
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.
Emphasis continues to be placed by medical authorities on epidemiological reasearch that, despite many thousands of childeren being measured in numerous studies, shows no link between MMR and autism. Some critics, 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 [3] (http://www.vaccinationnews.com/DailyNews/February2002/AutBowMeas.htm). For example, it can be difficult to find two populations of sufficient size which differ only in whether they were vaccinated. These criticisms have puzzled MMR's supporters, who point out that the anti-vaccine lobby has blamed MMR for a what it says is a staggering rise in the prevalence of autism, but at the same time argues that epidemiological methods are inadiquate to detect any relationship.
Dr. Wakefield left his job at the Royal Free Hospital in 2001. He now campaigns against the MMR vaccine on more or less a full time basis, travelling to the United States and Europe to lecture on the vaccine's alleged dangers.
In February 2004, it emerged that at the time that Dr. Wakefield had published his report, he was being paid £55 000 to help lawyers seeking evidence of a link between autism and the MMR vaccine. According to a Sunday Times investigation, several of the parents quoted as saying that MMR had damaged their children were also litigants. This was not revealed to either The Lancet or Dr. Wakefield's co-researchers. On February 20, The Lancet said that it should have never published Dr. 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 [4] (http://www.staffnurse.com/nursing-news-articles/mmr-autism-link-study-476.html). The General Medical Council, which is responsible for supervising medical ethics in the UK, has said that it is to investigate the affair [5] (http://briandeer.com/wakefield/gmc-announce.htm).
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. [6] (http://briandeer.com/mmr-lancet.htm) 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. [7] (http://briandeer.com/wakefield-deer.htm)
Recent Studies
- 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." [[8] (http://www.jpands.org/vol9no3/goldman.pdf)]
- In October 2004 a review, financed by the European Union, was published in the October 2004 edition of Vaccine [9] (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12922131&dopt=Abstract) 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 concluded that there was no link between MMR and autism, and that an eight-fold rise in the reporting of autism was due to an increased awareness of the disorder, a growth in services, and changing definitions. [10] (http://archpedi.ama-assn.org/cgi/content/abstract/159/1/37)
- In March 2005 a study of over 30,000 children born in one district of Yokohama concluded 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." [11] (http://www.blackwell-synergy.com/links/doi/10.1111/j.1469-7610.2005.01425.x/abs/?cookieSet=1) Reference: Journal of Child Psychology and Psychiatry (DOI: 10.1111.j.1469-7610.2005.01425.x) cited in New Scientist. [12] (http://www.newscientist.com/article.ns?id=dn7076) Dr. Wakefield rejects the conclusions of the research, by asserting "Following the introduction of MMR there was a rise in annual incidence of ASDs to 85.9 for children born in 1990. The incidence subsequently declined to 55.8 for children born in 1991. The incidence then rose again sharply, to a level of 161 (121.8-200.8) in 1994. During this time the single vaccine option gained further acceptance as public and professional confidence was restored following the removal of the Urabe mumps vaccine." Wakefield contends the pattern of autism rates revealed by the data support his hypothesis. [13] (http://www.redflagsweekly.com/articles/2005_mar06_2.html)His views, however, have found little support [14] (http://www.guardian.co.uk/uk_news/story/0%2C3604%2C1429115%2C00.html).
External links
- bbc.co.uk (http://www.bbc.co.uk/sn/tvradio/programmes/horizon/mmr_trans.shtml) - 'Does the MMR Jab Cause Autism?' (tv programme transcript), British Broadcasting Company (May 29, 2005)
- BMJJournals.com (http://bmj.bmjjournals.com/cgi/eletters/330/7483/112-d#) - 'Rapid Responses to: Increase in autism due to change in definition, not MMR vaccine' British Medical Journal (opinions exchanged at BMJ website)
- BrianDeer.com (http://briandeer.com/mmr-lancet.htm) - 'the Lancet scandal', Brian Deer ('investigation' of MMR affair)
- Jabs.org.uk (http://www.jabs.org.uk/) - 'The Support Group for Vaccine-Damaged Children' (a view on MMR from a UK advocacy group
- Medinfo.co.uk (http://www.medinfo.co.uk/immunisations/mmr) - 'Medical Information for Patients: MMR Vaccination'
- MMRTheFacts.NHS.uk (http://www.mmrthefacts.nhs.uk/) - 'MMR the Facts', United Kingdom NHS (government website)
- MMRTheQuestions.com (http://www.mmrthequestions.com/) - 'MMR: The Questions' (includes repsonse from Andrew Wakefield to Brian Deer's 'investigation')
- SpikedOnline.com (http://www.spiked-online.com/Articles/0000000CA7C7.htm) - '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)
Reference
- BMJJournals.com (pdf) (http://bmj.bmjjournals.com/cgi/reprint/324/7334/393?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&author1=taylor%2C+b&author2=miller%2C+e&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1113249908936_21240&stored_search=&FIRSTINDEX=0&sortspec=relevance&resourcetype=1,2,3,4) - '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