March 17, 2008|By Timothy F. Doran
Has the U.S. government acknowledged a link between childhood vaccines and autism?
A Maryland-born girl who has a rare genetic mitochondrial disorder and features of autism was recently compensated in a landmark case filed under the National Childhood Vaccine Injury Act. The Centers for Disease Control and Prevention says the "government has made absolutely no statement indicating that vaccines are a cause of autism" - a position supported by decades of research that has found no link between vaccines and autism. Yet an autism advocacy group claims otherwise.
So what's happening? And how should millions of nervous parents react?
The former Ellicott City girl, the daughter of a neurologist, was well until she was 7 months old, when she suffered recurrent ear infections. She reportedly developed normally until 19 months, at which time she received five common childhood vaccinations. After this visit, her development deteriorated and she was eventually diagnosed with a rare disorder that affects the energy-generating parts of our cells, and features of autism.
The award to her family creates confusion among the families of the infants ready to receive vaccines. A few days ago, a mother of one of my patients, herself a doctor, asked me why the government had made the award if the vaccines were not the cause of autism. The answer lies in a misunderstanding of the mechanism under which the girl was compensated.
Autism is a developmental disorder that affects the ability to understand language and relate to others. We now refer to "autism spectrum disorders" and "pervasive developmental disorders" as categories of autism. The rate of children diagnosed with autism has increased steadily over the last 20 years, but it remains unclear whether we are seeing an increase in autism or merely reclassifying children who were classified as having other developmental-delay disorders in the past. The rate of children diagnosed with mental retardation has declined significantly over the last decade for similarly unclear reasons.
Dozens of large-scale studies from multiple countries have failed to prove the association of MMR (measles-mumps-rubella) vaccine and autism, or between thimerosal (the mercury preservative that used to be in vaccines) and autism, and national reports from organizations such as the prestigious Institute of Medicine reject any association between vaccines and autism. Nevertheless, a large and vocal group of anti-vaccine proponents persist in making the claim that there is a causative link.
The original article that spurred all the debate about an association between MMR and autism, published by Dr. Andrew Wakefield, was based on 12 patients. His co-authors subsequently disavowed the article, and he was charged with professional misconduct by the UK General Medical Council.
Why do the doubts persist? One reason is that many have forgotten the devastating diseases that created public panic in the past, now rare or completely eradicated because of vaccines. For example, polio outbreaks in the 1950s engendered great fear. As a pediatrician in training, I cared for dozens of unfortunate children severely damaged by either haemophilus influenza or pneumococcal meningitis. Neither the public nor pediatric residents see such patients anymore, because of the astounding success of our vaccination program. Perhaps the awareness that vaccines are crucial to children's health wanes as successes become commonplace.
The media also play a major role in perpetuating misinformation about vaccines. The anecdotal stories of children "harmed" by vaccines are too compelling for many reporters to ignore. The Internet allows broad participation by vaccine opponents to create large and effective advocacy groups. The enlistment of Washington politicians further establishes the movement's bona fides.
Pediatricians faced a similar crisis of confidence in the late 1980s, when there was a suspicion that DPT shots caused sudden infant death syndrome. This link was later scientifically dismissed, but the experience led to the development of a no-fault vaccine compensation program - the system under which the girl from Ellicott City was compensated. The program was never meant to be a tort system, but rather to provide ready access for families to receive compensation for any possible vaccine injury. The award in this case comes from this source, yet is misperceived as assigning fault for her illness. It in no way substitutes for rigorous scientific study.
Understandably, the public is skeptical. The medical profession seems to reverse itself on major dogma with regularity. However, there is no real scientific debate on the benefits of vaccines. The overwhelming basic science, epidemiological and public health knowledge show that vaccines are safe and that they save lives and prevent devastating disability. And they do not cause autism.
Dr. Timothy F. Doran, chairman of the department of pediatrics at Greater Baltimore Medical Center, is former president of the Maryland chapter of the American Academy of Pediatrics. His e-mail is tdoran@gbmc.org.
