Four Seasons Pediatrics

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Vaccines & Autism

As parents, we want to do the best we can for our children.  They are our most precious assets.  As we step forward to accomplish this, vaccines to prevent illness are one option that many see as “a given” to prevent illness.   Modern medicine has given us so many and will continue to give us more vaccines.  It is normal for parents to ask – “Why so many?” and “Can the body handle all of these?”.  As you ponder these thoughts you hear from a well intentioned friend – “You know those shots are too much for the body, I am not immunizing my child!”.  You see a news story about the MMR vaccine causing autism.  A neighbor informs you that their child became autistic from all the mercury in vaccines.  You Google “vaccines and autism” and 3 of the top 10 web sites convincingly and strongly state that vaccines cause autism.  You read with interest discussions of “poisons”, “toxins” being forced upon your child.   All of this weighs heavy on your mind.  You begin to really re-think the idea that vaccines are worth the potential risk. 

What is autism?

Autistic spectrum disorders are a group of disorders characterized by varying degrees of poor social interactions and unusual behaviors and interests.   They are also known as Pervasive Development Disorders (PDD).  PDD can vary from mild to profoundly severe.  Current estimates from the CDC indicate that about 1 in 152 children have some form of autism.  The cause is not clearly understood.  We do know that genetic factors play a role, and there has been work done on our genetic make –up (DNA) identifying the location of the susceptibility.  We also know that more people have this genetic make up than show it.  It is speculated that some other event “activates” the gene.   However, except for congenital rubella infections, studies in epidemiology have not found a link between environmental causes and autism.  

There is also a debate about the number of people who have autism.  There have been a number of studies looking at the rise in the number of children diagnosed with autism.   There is a belief that most of the increase is coming from a change in how the diagnosis is labeled.  One of the best studies looking at autism tracked the diagnosis of autism from 1984 to 2003.  In that study published in Pediatrics, the growing prevalence of autism from 1994 to 2003 was associated with corresponding declines in the diagnosis of learning disabilities and mental retardation.  In other words, the diagnosis of autism increased while other non specific diagnosis categories increased.   Another study in England found that two forms of autism not recognized years earlier (Aspergers and PDD-not otherwise specified) accounted for almost 75% of the autism diagnoses in 1998-1999.    In addition, the diagnosis of autism allows financial coverage for school systems and insurance companies, making this an incentive in using this diagnosis.  While it may appear that most of the rise is from these issues, there are many who believe that there is also a small increase in autism beyond a change in labeling. 

What about the vaccines and autism?

With the rise in the number of diagnoses of autism and the increased number of vaccines, there are some that say the two must be linked.  In addition, the diagnosis of autism is commonly made between 15-24 months of age.  This is a time when many vaccines have been given or may be given.  It is important to note that this diagnosis is more apparent at this age because social communication really starts to take off, and difficulty in this area is more likely to reveal itself. 

There are two theories about the role of vaccines and autism.  The first involved the use of thimerosal (a mercury like compound used as a preservative).  Since thimerosal is no longer used in almost all childhood vaccines, has been disproven as a cause of autism and the number of cases has not been affected, we will focus on the other ongoing theory.  This theory involves measles vaccine.

The theory regarding measles vaccine first evolved in 1998 when Dr. Andrew Wakefield described 12 children with PDD and gastrointestinal symptoms.   The study reported that in eight of the cases, symptoms began within two weeks after receiving the MMR vaccine.  Although the report contained no proof of a link between MMR vaccine and autism, a headline in London’s The Daily Telegraph read “Vaccination may trigger disease linked to autism”.   Major news media picked this story up and it has been a recycled story for the past 11 years.  In 2004, 10 of the 13 authors of the Wakefield study formally retracted their hypothesis.  The Institute of Medicine reviewed 16 studies which all consistently showed no association between MMR and autism.    Wakefield and his team also claimed that measles virus lodged in the intestines, releasing toxins that affected the brain, thus causing autism.  Not only could other researchers not replicate Wakefield’s reports, but the methods that Wakefield used were also shown to have been flawed.  It claimed that the doctors or families of eight out of twelve children attending a clinic at the hospital had blamed MMR for their autism, and said that problems came on within days of the immunization. The team also claimed to have discovered a new inflammatory bowel disease underlying the children’s conditions.

In February 2009, The Times (London) revealed the following:  In most of the 12 cases, the children’s ailments as described in The Lancet were different from their hospital and physician records. Although the research paper claimed that problems came on within days of the immunization, in only one case did medical records suggest this was true, and in many of the cases medical concerns had been raised before the children were vaccinated. Hospital pathologists, looking for inflammatory bowel disease, reported in the majority of cases that the intestine was normal. This was then reviewed and the Lancet paper showed them as abnormal.  An investigative reporter with the same newspaper reported that Dr. Wakefield was paid handsomely to try to prove that the MMR vaccine was unsafe.  While you have likely heard the impact of Dr. Wakefield’s study, you are just as unlikely to have heard about all the faults and corruption with Dr. Wakefield’s study.

Despite involving just a dozen children, the 1998 paper’s impact was extraordinary. After its publication, rates of immunization fell from 92% to below 80%. Populations acquire “herd immunity” from measles when more than 95% of people have been vaccinated.   Official figures showed that 1,348 confirmed cases of measles in England and Wales were reported 2008, compared with 56 in 1998. Two children have died of the disease.

The theory that measles vaccine causes autism has been fully disproven.  Nevertheless, the MMR scare has attracted and continues to attract so much media attention that MMR immunization rates fell in part, if not completely, because of misinformation about this safety concern.  Subsequently, there have been outbreaks of measles in Great Britain, the Netherlands, Germany and Switzerland; and an epidemic of mumps in Great Britain (which was the likely source of an outbreak in the United States in 2006).

The IOM report in 2004 concluded that there was no evidence of link between vaccines and autism.  There has been a steady stream of studies that have been well done in the medical literature.  These well done studies have consistently disproven vaccines as a “cause” for autism.

The continued public “controversy” in the face of the scientific evidence is now considered to be misinformation.  Aggressive misinformation about vaccines causing autism-presented as fact by prominent individuals – has been featured in publications and by the news media, discussed on popular TV and radio talk shows, and been the subject of TV dramas and docudramas.  Because these articles feature compelling stories often by prominent people, it is little wonder that parents have been confused. 

For more information and more details we encourage you to read our reference


Do Vaccines Cause That?! – A Guide for Evaluating Vaccine Safety Concerns by Martin G. Myers, MD and Diego Pineda

Times Story – Feb 2009 on Dr. Andrew Wakefield

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