NEW YORK — 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, had found a link among the vaccine, gastrointestinal problems found in many autistic children and autism. New evidence has now put that theory 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 appear responsible for autism in children. According to Deer, the Wakefield paper was an “elaborate fraud.”
The erroneously reported link to autism has led thousands of parents to withhold MMR vaccine from their children, making them susceptible to illness and provoking hundreds of deaths. In February 2010, The Lancet retracted the original Wakefield article, stating that its authors had made false claims about the study and drawn wrong conclusions. In May 2010, Britain stripped Wakefield of his medical license.
Deer’s study showed that time lines in the Wakefield study were altered to make it seem as if autismlike symptoms had developed soon after vaccination, when in fact the problems had developed either before, or months after, vaccination.
Autism, a complex developmental disorder that begins in early childhood, has three defining features: Problems with social interaction, impaired verbal and nonverbal communication, and a pattern of repetitive behaviors. The wide range of symptoms presented are called autism spectrum disorders (ASDs).
The U.S. Centers for Disease Control and Prevention (CDC) estimates that one in 110 children in the United States has an ASD. If one assumes that the prevalence rate has been constant over the past two decades, one can estimate that about 730,000 individuals up to the age of 21 have an ASD. Studies in Asia and Europe have identified the ASD rate among individuals at 0.6 percent to more than 1 percent.
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 stated that Thimerosal (Ethylmercury), used 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 10 of Wakefield’s 12 collaborators in the study. In addition, in 2007, a CDC study didn’t support any association between early exposure to Thimerosal in vaccine and nervous system disorders in children between the ages of 7 and 10.
Despite this evidence, many parents didn’t allow their children to be vaccinated. In 2008, according to the CDC, more measles cases were reported in the U.S. than in any other year since 1997. More than 90 percent of those infected either had not been vaccinated or had an unknown vaccination status.
The Wakefield fraud shows the harm that can be visited on children’s health. It also shows the tremendous social and economic costs to society. It renews the urgency to find the causes of autism. Diagnosis at an early age is essential for treatment that can do the most good and help autistic children integrate effectively into their community.
Cesar Chelala, M.D., is an international public health consultant.