Vaccines and Autism - Is There a Link?

November 2005
Is There a Link between Childhood Vaccines and Autism?
By Joyce Heid

Twenty years ago, most people could not describe autism. Today, “autism” has practically become a household word.
According to the American Academy of Pediatrics and the Center for Disease Control (CDC), currently, 1 in 6 children are diagnosed with a developmental disorder; 1 in 166 children are diagnosed with a disorder within the autism spectrum.
Autism is a neurological disorder that is characterized by social withdrawal, repetitive behaviors and the inability to relate to others. Theories as to the cause of the dramatic rise in children diagnosed with autism-related disorders are almost as varied as the disorder itself. These include diet, environmental causes, ultrasound and preservatives in vaccines.
The presence of preservatives in vaccines—specifically, an ingredient known as thimerosal—has become the leading theory in the puzzle.
What exactly is thimerosal? It is a mercury-containing organic compound commonly used in multi-dose vaccine vials. Packaging vaccines in bottles containing multiple doses is more cost-effective. However, the vials also become prone to contamination from repeated punctures. Thimerosal prevents microbial growth in the event that a vial is accidentally contaminated. Although thimerosal has been in existence since the 1930s, children were not exposed to large amounts of it until 1989, when a new childhood vaccine schedule was implemented.
Prior to 1989, children in the United States received a series of 11 injections of three childhood vaccines. In 1989, the CDC mandated an increase in vaccines—increasing the series to 24 injections. Many of these vaccines contained thimerosal.
Since then, autism rates have skyrocketed, from 1 in 10,000 in the early 1980s to 1 in 166 today.

The Thimerosal Generation
Thimerosal is approximately 50 percent mercury by weight. People who eat certain seafood are commonly exposed to low levels of organic mercury, which the body can eliminate. The mercury in thimerosal is different. Once injected, it goes to the brain. There, it changes from organic mercury to inorganic mercury. As inorganic mercury, it is not expelled from the body, and it binds to the tissues in the brain.
Children vaccinated between 1989 and 2003 have been called the Thimerosal Generation, with more than 500,000 of those children diagnosed with autism and thousands more identified each year. Most children are diagnosed with the disorder between the ages of 2 and 4 years old.
The 1989 change in the vaccine schedule dramatically increased the exposure to mercury for infants. At 2 months of age, an infant received 125 times the Environmental Protection Agency’s limit for daily exposure to mercury for body weight. At 6 months of age, an infant received 40 times the limit.
In other words, at a time when the brain is rapidly developing, a neurotoxin was introduced that could cause significant damage.
Many people, including researchers, doctors and parents, have tried to link the rise in autism to the increase in mercury exposure. After all, autism is a neurological disorder, and mercury is a known neurotoxin.
Others, including the CDC, dismiss the theory. Instead, they associate the increased rise to increased awareness of autism. Even so, in July 1999, the Public Health Service agencies, the American Academy of Pediatrics and vaccine manufacturers agreed that thimerosal should be reduced or eliminated in vaccines as a precautionary measure. Thimerosal was gradually phased out. Today, it has been removed or reduced to trace amounts in all routine vaccines for children under the age of 6, with the exception of some influenza vaccines.
If the theory linking thimerosal to autism holds true, autism rates should begin to decrease in the coming years. (For example, California—considered to have one of the most accurate reporting systems for autism in the U.S.—has recorded an annual decrease in its autism rate since the removal of thimerosal.)
Why didn’t thimerosal harm every child who was vaccinated? Why are there more boys than girls diagnosed with developmental delays and autism? On average, 1 in 166 children are diagnosed with autism; for boys, the average is 1 in 80.
My own son was diagnosed with developmental delay. He attended a special needs preschool for three years. The first year, two girls were in his class, the second year just one and the final year, none.
Some researchers link the proportion of testosterone to the damage caused by thimerosal. They conclude that testosterone can make it easier for thimerosal to damage cells. In addition, researchers also believe that genetic make-up might cause one child to be more susceptible to toxins such as mercury than another child.

A Heated Controversy
Why is the link between thimerosal and autism such a controversial issue? There is the question of whether the manufacturers were aware of the danger before children were exposed. Reports of secret meetings, destroyed documents, altered research data abound. Negligence has been implied not only on the part of the drug manufacturers, but also on the part of government agencies including the CDC and the Food and Drug Administration (FDA). But the question remains, even though thimerosal has been removed or reduced to trace amounts now, what about those children who have already been exposed?
If it were recognized that drug manufacturers were aware of the relationship between thimerosal and autism, they could be held liable for the damage done to these children. The lawsuits that could follow could cripple the vaccine industry.
Senate Majority Leader Bill Frist, M.D. (R-Tennessee) has tried on several occasions to deny compensation to children suffering from vaccine-related disorders by attaching provisions to anti-terrorism bills and homeland security legislation. According to Dean Rosen, health policy advisor to Frist, in a recent Rolling Stone article, “The lawsuits are of such magnitude that they could put vaccine producers out of business and limit our capacity to deal with a biological attack by terrorists.”
Other bills, including H.R. 534 and S. 354, would place limitations on compensation, reduce the statute of limitations for children and allow damages to be paid periodically.
On the other hand, Senator Joe Lieberman (D-Connecticut) introduced measures to counter provisions that would protect vaccine manufacturers. Many states have passed legislation banning the use of thimerosal, including Missouri, Iowa, Delaware, New York, California and Illinois.
Last year in Maryland, Delegate Terry Gilleland (R-Linthicum) introduced legislation that would have reduced mercury exposure in children and pregnant women in Maryland. Unfortunately it never made it to a vote, but it will be reintroduced in the 2006 session.
Pasadena resident Nic Kipke, a candidate for the Maryland House of Delegates, District 31, has been actively advocating for families of children with autism for years. A member of the Maryland Autism Recovery Coalition and Unlocking Autism, Maryland Chapter, Kipke is adamant about the dangers of thimerosal.
“I would invite any elected Republican or Democrat to volunteer to get injected with the concentrations of mercury given to children,” he declares. “I don’t think one of them would do it... At the core of this initiative is common sense. Very simply put: Mercury is bad, get it out of our vaccines!”

Vaccines Still Necessary
It is important to remember that no one on either side of the debate is anti-vaccine. The struggle is to make the vaccines safe and to ensure the safety of our children in the future. Dr. Mark Geier, president of the Genetic Centers of America, has worked with vaccines for more than 30 years and was with the National Institute of Health for 10 years. He travels the world expounding on the dangers of thimerosal, yet also emphasizes the importance of vaccines.
“I am strongly pro-vaccine. Vaccines are the greatest invention of the last century,” he maintains. “However, there are many places where they can be improved.”
According to Geier, when he first approached the CDC about thimerosal, he was told that it would be more dangerous to publicize the dangers because people would not get their children vaccinated.
“You can buy a mid-size car, and there are five or six companies. You can get the crash test results. You can pick which one you want,” Geier observes. “[Vaccines] are made by more than one company in most cases. Maybe one is better than the other.”
Geier encourages parents to be informed consumers, “All vaccines that are required for children are available with either no thimerosal or trace thimerosal—less than 1 micro gram—therefore no one needs to take the 25-micro-gram vaccines. No child needs to go unvaccinated, but no one should be exposed to thimerosal.” BC

To Read More about Thimerosal
*The Institute for Vaccine Safety website, www.vaccinesafety.edu/thi-table.htm. As part of the Johns Hopkins Bloomberg School of Public Health, the Institute’s website includes a vaccine table listing by brand which vaccines have thimerosal and which do not.
*Thimerosal-News website, www.thimerosal-news.com. This includes several articles on the topic.
*Evidence of Harm, by David Kirby (St. Martin's Press, 2005).