The theory that the measles, mumps and rubella (MMR) vaccine was responsible for causing autism has, since it was first elaborated, been a hindrance to a proper assessment of the autism problem. The theory, based on a study led by Dr. Andrew Wakefield, published in The Lancet in 1998, purported to have found a link between the vaccine, gastrointestinal problems found in many autistic children and autism. New evidence has now put that theory finally to rest.

A recent report published by the British Medical Journal, based on a study conducted by British investigative journalist Brian Deer, concluded that the medical histories in the Wakefield study had been misrepresented to make the vaccine responsible for autism in children. According to Deer, the flaws in Dr. Wakefield paper were not honest mistakes but an “elaborate fraud.”

The Deer study is particularly relevant since the erroneous link between vaccines causing autism has led thousands of parents to withhold the MMR vaccine to their children, making them susceptible to illness and provoking hundreds of deaths. In February of 2010, The Lancet retracted the original Wakefield article, stating that its authors had made false claims about how the study was conducted and leading to wrong conclusions. In May of 2010, Britain stripped Wakefield of his medical license.

Mr. Deer’s study showed that time lines in the Wakefield study were altered to make it seem as though autism-like symptoms had developed soon after vaccination, while in reality problems had developed before vaccination and in other cases months after vaccination.

Autism is a complex developmental disorder that begins in early childhood and that has three defining main features: Problems with social interactions, impaired verbal and nonverbal communication and a pattern of repetitive behaviors. They present themselves with a wide range of symptoms and varying degrees of problems. This group of disorders is called autism spectrum disorders (ASDs).

The US Centers for Disease Control and Prevention (CDC) estimates that an average of 1 in 110 children has ASD in the US. If one assumes that the prevalence rate has been constant over the past two decades, one can estimate that about 730,000 individuals between the ages of 0 to 21 have an ASD. Studies in Asia and Europe have identified individuals with ASD with a prevalence of approximately 0.6% to over 1%.

The MMR vaccine’s effect on autism is one of the most controversial theories regarding the origin of this disorder. Many believers in this theory state that the use of Thimerosal (Ethylmercury) as a preservative in the vaccines could be responsible for the symptoms developed by many children after vaccination. However, rates of autism and ASDs continued to increase even after Thimerosal was no longer used as a preservative in vaccines in 2001

In 2004, the interpretation of a causal link between the MMR vaccine and autism was formally retracted by ten of Wakefield’s twelve collaborators in the study. In addition, in 2007, a CDC study didn’t support any association between early exposure to Thimerosal in vaccines and nervous system disorders in children between the ages of 7 and 10 years.

In spite of this evidence, many parents didn’t allow their children to be vaccinated increasing the likelihood of disease outbreaks. In 2008, according to the CDC, more measles cases were reported than in any other year since 1997. More than 90% of those infected had not been vaccinated or their vaccination status was unknown.

The Wakefield fraud shows the considerable damage that this kind of event can have on children’s health. It also renews the urgency to find the cause/s of autism, taking into consideration that diagnosis is essential for appropriate treatment at an early age, when it can do most good, and help autistic children integrate effectively into their community.

Dr. Cesar Chelala is an international public health consultant.