No evidence that vaccines cause autism
Friday, March 28, 2008
Recently the ABC legal drama "Eli Stone" featured an episode where a parent was suing the makers of a vaccine claiming it had caused autism in her child. The jury awarded the mother $5.2 million, leaving audiences with the destructive idea that vaccines cause autism.
The American Academy of Pediatrics, which represents more than 50,000 pediatricians, requested the episode not be aired. In a letter to ABC, Dr. Renee Jenkins stated "A television show that perpetuates the myth that vaccines cause autism is the height of reckless irresponsibility … If parents watch this program and choose to deny their children immunizations, ABC will share in the responsibility for the suffering and deaths that occur as a result. The consequences of a decline in immunization rates could be devastating to the health of our nation’s children."
Let’s be clear. Vaccines do not cause autism. It is scary to think that they might and it is understandable that parents would want to be sure. That’s why this theory has been evaluated through research in many countries involving hundreds of thousands of children. The evidence has been reviewed by countless researchers in numerous scientific and regulatory organizations including The Centers for Disease Control and Prevention, the American Academy of Pediatrics, the Institute of Medicine of the National Academy of Sciences and the Food and Drug Administration. All have come to the same conclusion: there is no evidence that vaccines cause autism. None.
So why is there still a controversy if the issue has been disproved? Probably the most important and understandable reason is that parents of children with autism want to know why their child has the disorder. Medical science can’t answer that question yet. In the absence of a clear reason some parents blame immunizations because the diagnosis of autism is often made around the time of an immunization. But just because two things seem to occur around the same time does not prove they are related.
To add to the confusion, last November the National Vaccine Injury Compensation Program awarded a settlement to a little girl stating that vaccinations may have aggravated her mitochondrial disorder. She also has "autism-like symptoms." However, the government says vaccines did not cause her autism but aggravated a condition that was already present. A "mitochondrial disorder" is a rare medical disorder that can cause brain damage and often emerges after a period of normal development. In other words, the vaccines together with a mitochondrial disorder may have exacerbated her condition, but the condition was present before the vaccinations.
That still leaves the question of why there are more children today with autism than ever before. It may be related to the fact that the definition of autism has been broadened and is now considered a group of disorders. There are guidelines for diagnosis and physicians are more aware of autistic disorders than in the past. The rise in diagnosis may simply reflect increased awareness of the disorder among doctors. In other words, children who are diagnosed with an autistic disorder today may not have been given that diagnosis if they were born in the 1960s even if they had the exact same symptoms.
It is also possible that there is a real rise in the disorder for reasons we don’t yet understand. There is currently a great deal of research dedicated to this issue.
Early in the immunization/autism debate it was suggested the preservative thimerosol, which contains mercury, was to blame. Thimerosol had been used in vaccines since the 1930s, but erring on the side of caution the AAP and the FDA requested that vaccine manufacturers remove thimerosol and they did. Some parents wondered why it was removed if it was truly harmless and the controversy grew. It should be noted that rates of autism did not go down after the removal of thimerosol, but the debate still remained and new arguments arose for why immunizations were to blame. Some parents went so far as to change the immunization schedule for their child or to forego immunizations altogether.
In some cases parents’ decisions to under-immunize their children has led to disease outbreaks. In Britain there were more than 5,000 cases of mumps in 2005 and 449 cases of measles in the first five months of 2006 because of under-immunization. The country reported the first measles-associated death since 1992 and two children suffered permanent brain damage. One in five children were infected in the Dutch epidemic of 1999 and 2,000 had serious complications. Five children were left with permanent brain damage and three children died. These diseases were all preventable with immunizations.
Fifty-three years after the development of the polio vaccine most doctors in this country have never seen a single case of the disease that caused nationwide panic in 1952 and 1953 with more than 90,000 people infected. That’s also true for mumps, rubella, diphtheria and tetanus.
According to the CDC, before 1963 there were more than 3 million cases of measles and 500 deaths reported every year. In 2002, there were only 44 cases of measles nationwide. And now with the development of the vaccines against haemophilus influenza (Hib vaccine) and pnuemococcus (Prevnar) today’s young doctors have never seen the terrible diseases caused by these bacteria, which were commonplace during my pediatric training just a few years ago.
It is tempting to believe the arguments against immunizing children. Full page ads have been placed in newspapers with claims that would scare any parent, celebrities have publicly aired their concerns and now ABC television has fanned the flames with its "Eli Stone" episode. But the science and the evidence simply do not support any association between vaccines and autism.
One thing that is certain and is not debated—vaccines prevent the diseases they inoculate against. And it is abundantly clear that in doing so, vaccines save children’s lives.
Dr. Lisa Thornton, a mother of three, is director of pediatric rehabilitation at Schwab Rehabilitation Hospital and LaRabida Children’s Hospital. She also is assistant professor of pediatrics at the University of Chicago. E-mail her at firstname.lastname@example.org.