July 2001

"MMR is as safe as a vaccine can get"

Institute of Medicine says evidence shows no association with autism and recommends MMR to protect against measles, mumps and rubella

News dated 25.04.2001

"MMR is as safe as a vaccine can get." This is the advice to parents from the US Institute of Medicine in the words of Dr. Marie McCormick of Harvard University's School of Public Health, Chair of a panel set up to review the evidence of a link between MMR and autism.

US federal health officials asked the Institute of Medicine last year to evaluate the safety of the vaccine used to prevent measles, mumps and rubella (German measles) after concerns were raised that it might trigger the incurable developmental disorder autism in some children.

Medical opinion is united

The conclusion that "the evidence favours rejection of a causal relationship at the population level between MMR vaccine and autistic spectrum disorders (ASD)" is in line with that of the Committee on Safety of Medicines (CSM), the Joint Committee on Vaccination and Immunisation (JCVI), the Medical Research Council (MRC), the Medicines Control Agency (MCA), the World Health Organisation and a newly released statement from the American Academy of Paediatrics (AAP), not to mention the British Medical Association, the Royal College of General Practitioners, and the Royal College of Nursing.

Further information

See the 10 page executive summary as an Acrobat file: IoMsummary.pdf (35kB) and a four page summary: IoM4Pager.pdf (22kB), or see the report on the IoM web site at

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The importance of research

Additionally, the committee said there have been no animal studies linking MMR vaccine and autism and that suggested biological mechanisms connecting the vaccine and autism have not been proven in controlled studies.

The IoM report, however, did not entirely shut the door on the remote chance of a link, saying research tools may lack the precision to detect rare side effects, but then this is true of all medicines. The panel recommended that the U.S. government continue to support research efforts and more rigorous data-gathering on the vaccine and on autism.

The independence of the judgement

Members of the committee are all health care professionals selected to exclude any who have a financial or advisory connection with vaccine manufacturers. The IOM is part of the National Academy of Sciences, an independent organisation of scientists and other experts which does research at the request of the government.

The AAP opinion

There is no link with inflammatory bowel disease

Separately the American Academy of Paediatrics (AAP) have concluded a review of the evidence around MMR and autism and Inflammatory bowel disease. "The bottom line is that a considerable body of evidence does not support a causal relationship between MMR vaccine and autism or inflammatory bowel disease," they say.

Separate vaccines are unnecessary

The AAP has also rejected the use of single vaccines in place of MMR, saying, "No data exist to suggest that separate administration of measles, mumps and rubella vaccines would offer any potential benefit over the MMR vaccine currently used.... Furthermore, there is ample reason for concern that such an approach would result in many underimmunised children."

The importance of a immunising children

Dr. McCormick warned of possible "devastating disease outbreaks" if parents refrained from having their children vaccinated due to the autism fears. "If left unchecked, infectious disease like measles, mumps and rubella could cause considerable sickness and death."

The origin of the controversy

Research by a British doctor in 1998 sparked concern that the vaccine was linked to a perceived increase in the incidence of autism, a severe neurological disorder. This has caused a small but significant drop in uptake of MMR from a peak of 92% in 1995 to the latest figure of 87.4%. Although this shows that the vast majority of the population recognise that MMR is the safest way to protect their children, this level is not sufficient to prevent the resurgence of these diseases in the longer term.

What is autism?

Autism is a permanent neurological disorder. Children with autism generally have difficulty communicating, may become obsessed with repetitive motions, such as head rolling, behaviour such as uncontrollable head banging and screaming fits, and often are intolerant of changes in their environment. They also may have learning difficulties.

Scientists generally agree most cases of autism result from events that occur in the prenatal period or shortly after birth. But the symptoms typically are not seen until the child's second year - at about the same time the MMR vaccine is administered. This can explain why it was originally thought that there was a link between the two.

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