There has been a lot of recent publicity about an alleged link between the MMR (Measles, Mumps, and Rubella) vaccine and autism.  Medical evidence does not support such a link.

Autism is a lifelong developmental disorder characterized by poor social interaction, communication difficulties, and repetitive behaviors.  Although rarely diagnosed before age two, autism is thought to have its origins in genetic factors and prenatal injury.  In the last twenty years the umbrella diagnosis of Autism Spectrum Disorder was developed to emcompass not only classically autistic children, but also children who have autistic features but fall short of meeting the criteria for autism.  Such children may carry diagnoses such as Pervasive Developmental Disorder (PDD), Rettís Syndrome, or Aspergerís Syndrome.  It is currently estimated that 1 in 1,000 children have Autism Spectrum Disorder, and the rate has risen considerably in recent years.  There is currently no definite answer as to why the rate of autism is rising, although increasing awareness and more accurate diagnosing probably play a role as well.  Early diagnosis with speech and behavior therapy is the only effective treatment for autism.

The origin of the alleged MMR-autism link is a paper published in the British medical journal Lancet in 1998.  In the study, Dr. Andrew Wakefield and colleagues studied twelve children with behavior and language problems, most of whom had autism.  The study describes a pattern of bowel problems (bloating, abdominal pain, diarrhea, food intolerance) in all twelve children.  The authors propose the bowel problems would cause poor absorption of essential nutrients, which in turn caused autism in the children.  The MMR vaccine was then temporally implicated as the cause of the bowel problems.  Dr. Wakefield has also published subsequent studies that claim to find a higher likelihood of finding MMR vaccine virus present in the gut of autistic children.

Dr. Wakefieldís studies have many flaws and have been thoroughly discredited by other investigators.  His 1998 study implies that bowel problems are the cause of autism, yet only two of the twelve children were documented to have bowel problems prior to the onset of autism.  His recent studies are deceiving because MMR vaccine virus fragments can be isolated from any childís bowel right after vaccination, and he does not give the ages of the patients in his studies.  Multiple studies in several different countries, including England and Finland, show no change in the rate of autism following the introduction of MMR.  The most comprehensive review on this topic was published in 2001 by the Institute of Medicine, a group commissioned by the CDC (Centers for Disease Control) and the NIH (National Institutes of Health).  The Institute of Medicine examined all available scientific evidence on the topic of MMR and autism and concluded that there is no link between the two.

Several recent reports have advanced the idea that giving the measles, mumps, and rubella vaccines separately is safer than the combination MMR vaccine.  Because of the absence of a credible link between MMR and autism, we do not believe this is safe or practical.  Administering the three vaccines separately can leave your child unvaccinated for a longer period of time.  While the incidences of measles, mumps, and rubella are low in the United States, a lapse in immunization rates can easily bring them back, with devastating consequences.  In 1990-1991, during the last measles epidemic in the United States, 55,000 people contracted measles and 123 died.

Major autism groups such as the Autism Society of America and the National Association for Autism Research continue to support routine use of MMR vaccine.

**update 3/04** In February of 2004, Lancet revealed that Dr. Wakefield had not disclosed during the submission of his 1998 paper that he was working on behalf of consumer groups that were looking to sue vaccine manufacturers.  No prior report of a connection between MMR and autism existed at the time, and the Wakefield study was the first.  The editors of Lancet reported that this relationship calls the validity of the study into question and had they known of this connection they would have never published the study.  The Lancet report effectively withdraws any credibility that the Wakefield study may have had.