Researcher studies connection between autism, vaccines

Dr. David Ayoub, the self-taught expert on vaccines, mercury and the autism epidemic, stood in the back of the room on the second floor of First United Methodist Church in Normal, Ill., recently on the verge of a lecture.

He faced the backs of his audience. They all faced a portable tripod screen that would soon display a dizzying torrent of Power Point charts, graphs, facts and statistics for the consumption of the standing-room crowd of Illinois State University college students, instructors and people whose connection to the misery, mayhem and melancholy of autism were more personal, confounding and intense.

He began: "You might wonder that a radiologist who doesn't have a child with autism might come across as being a little bit on the fringe (on this topic)," Ayoub said, the light touch of self-deprecation, depending on a person's point of view, either cementing his credibility or undermining it. "I just want to know the truth like I'm sure you just want to know the truth."

Ayoub then tore into his short-form two-hour lecture (he said he has eight hours of material), preaching to the choir, firing up his base, trolling for converts.

"You might as well not take notes," said Ayoub, a Peoria native and high school track superstar, who now lives in Springfield, Ill. "You won't keep up."


The absolute truth about autism and mercury is as slippery and hard to grab as a bead of quicksilver on a clean glass surface. It's no longer dismissed as a wild-eyed theory clung to by desperate-for-answers family members of children with autism. The debate over whether mercury-laced vaccines administered to infants and toddlers in increasing amounts in the 1990s sparked an autism epidemic has entered the realm of more mainstream science. And appears not yet ready to fade away.

The lines, however, are still sharply drawn and both sides are dug in deep. Public health agencies, both the American Medical Association and American Pediatric Society, and the makers of the vaccines - powerful and influential institutions all - maintain the unified front that the vaccines and vaccine schedules are now, and have always been, safe.

That there might, might, be a connection between mercury and autism is an idea that has gathered momentum in recent years. More and more medical professionals and researchers, like Ayoub, politicians and the burgeoning population of autism families have been absorbing the voluminous amount of literature and data and coming up believers. A book that laid out the case for the mercury and autism connection, "Evidence of Harm" written by David Kirby, was a New York Times best seller last year and landed the author on "Meet the Press" where he debated the topic with Harvey Feinberg, the director of the Institute of Medicine.


Here's what drives the controversy:

Mercury is among the most toxic agents on earth and is a known neurotoxin. Autism, once thought to be the result of bad parenting, is now designated as a neurological disorder.

Autism was first described in medical literature in 11 case studies written by Dr. Leo Kanner in 1943, 14 years after thimerasol, a mercury-based preservative used to keep vaccines from contamination, was developed by the drug company Eli Lilly. Unheard of before Kanner's case studies, autism remained consistently rare until the 1970s. In the United States the incidence of autism in that period was between 1 and 3 per 10,000 children; it rose to 20 to 40 children per 10,000 births in 1998. Today the rate is one in 166 births.

The startling increases coincide with an increase in the number of vaccinations infants and toddlers receive in the natural course of their pediatric care as new shots were added to the schedule. Even though each shot contained only traces of thimerosal, the cumulative amount raised concerns to some. The Los Angeles Times cited an internal drug company memo from 1991 it had obtained that said that "6-month-old children who received their shots on schedule would get a mercury dose up to 87 times higher than guidelines for the maximum daily consumption of mercury in fish."

Public health officials say there is no evidence of a link between mercury, vaccines and autism. Better diagnostic skills and an expanded definition of what sort of behaviors fit on the autism spectrum explain most of the increase in rates.

Still, in July 1999 the Centers for Disease Control and Prevention recommended that thimerosal be removed from most vaccines as a precaution. Here is its explanation:

"A review conducted by the Food and Drug Administration concluded that the use of thimerosal as a preservative in vaccines might result in the intake of mercury during the first six months of life that exceeds the Environmental Protection Agency, but not the FDA, the Agency for Toxic Substances and Disease Registry or the World Health Organization guidelines for methylmercury intake.

Thimerosal contains ethylmercury. Methylmercury is a related compound and has been more thoroughly researched than ethylmercury. Thus, federal safety standards are based on information we have about methylmercury.

FDA's review found no evidence of harm caused by doses of thimerosal in vaccines, except for minor local reactions."

Ayoub is mistrustful of the CDC's claim.

"It just kind of sounds funny," he said at his Illinois State University lecture. "They're saying (thimerasol) causes no harm, but get it out (of vaccines) as soon as possible."


Ayoub is well-known in certain circles in Peoria for reasons that have nothing to do with autism. The Peoria High School graduate is in the Peoria Sports Hall of Fame mostly for his state championship race in the half-mile that was the fastest nationally at the time and remains one of the fastest ever and the fastest in Illinois almost 30 years later.

He went on to run track at the University of Illinois. Then he went to medical school. He is a part-time radiologist and works out of Springfield's Memorial Medical Center, an assistant professor at Southern Illinois University School of Medicine and the unpaid medical director of the Prairie Collaborative, an immunization watchdog group.

It might not surprise those who lost track of Ayoub when he left Peoria that he would emerge in the public eye a passionate activist for an underdog of an idea. Though knee surgery ended, for now, his running days, Ayoub maintains his championship runner's doggedness, focus and intensity. Fluent in science-speak, the words burst forth with rapid-fire assuredness that falls on this side of benign zealotry.

Actually it was the knee surgery three years ago that led to his interest in mercury, vaccines and autism, a medical debate far removed from his radiology background. Laid up, Ayoub exercised his mind by poring through medical journals and studies and came by accident upon the autism controversy.

"The more I read, the more I was drawn into the issue," said Ayoub, in a recent interview in his cramped office at Memorial Medical Center in Springfield. "The material is compelling."


Since his self-education, Ayoub has traveled the country to Defeat Autism Now conferences and others and has testified before two state legislatures, Illinois and Massachusetts. The opposite of a paid position, he figures he has spent about $30,000 of his own money. He lectures for free.

His technique is to critically study the available literature, look for conflicts of interest and results that may have been spun.

"You can do so much with studies to make them say anything you want them to," he said. "I try to get behind the numbers and statistics to find what a study is truly saying."

For instance, a study in Denmark is often cited as counter-argument of the autism-mercury link, by showing that reported new cases of autism did not decline after thimerasol was removed from all vaccinations in 1992. Ayoub shows that the authors of the study didn't sample a consistent population of patients, thus the results are skewed. He believes it is proof of nothing.

Ayoub believes there are innumerable paths to the autism spectrum. There are people with autism who had no exposure to thimerasol, and not everybody who received vaccinations with thimerasol has autism. There might be genetic and environmental causes and either one might work in concert with the introduction of even small amounts of mercury into a child's system and create a recipe for autism.

"The point is to keep looking until answers are found," Ayoub said.


For many parents of children with autism, theory makes sense

Copley News Service

While scientists, doctors, public health officials and researchers debate whether a link exists between autism and trace amounts of mercury once found in childhood vaccines, there is one place in the United States where the argument was settled long ago:

Inside a lot of homes of families with children with autism.

Prevailing medical opinion be damned, many parents are true believers.

"I completely believe my son's autism came from the end of a vaccination needle," said Paula Sessing of Peoria, Ill., who joined a lawsuit with hundreds of other plaintiffs filed in Texas against the federal government seeking compensation. "He was born typically normal and at the 9-month mark he went in and received several vaccinations in one trip and the bizarre behavior started almost immediately."

That's called "anecdotal" evidence of a link, and in the eyes of medical researchers, one story, no matter how compelling, doesn't prove anything. Sessing moderates an Internet autism group that has more than 3,500 subscribers.

"You'd be amazed at the number of stories just like mine," Sessing said.

Susan Grimm of Groveland, Ill., has two autistic sons and a nephew with Asperger's, a milder form of the disorder often characterized by hyper-intelligence instead of the withdrawn isolation of autism. Her sons were immunized within the timeframe of the autism epidemic, and she was at risk in other ways. She received eight dental amalgam fillings that contain small amounts of mercury and received shots in the military she suspects contained thimerasol.

"I believe there is a genetic predisposition for autism that thimerasol might trigger in some people and not in others," Grimm said. "Just like if you had lung cancer in your family it would be stupid to smoke, if you're genetically susceptible to heavy metals you might want to avoid shots with mercury in them."

Like Sessing's son, Grimm's son was developing at a normal pace when he received a vaccination shot at 18 months.

"He had a local reaction that was bigger than a quarter around the site of the shot, and he came home and just collapsed and slept and slept and slept," she said. "It was very concerning."

Soon thereafter he stopped singing his ABCs. Then he stopped talking. Grimm has had some success with chelation, a treatment program that removes heavy metals from the body. Now both of her sons are fully verbal.

Lauri Hislope of Peoria, the current president of a local autism support group and information clearinghouse, says her son Kyle was "assaulted by vaccine." After developing normally up until 16 months, his turnaround was dramatic and fast. In 2004 at 13, Kyle was too disruptive, violent, unpredictable and such a drain on the family's emotional state that he moved to the residential Hope School in Springfield.

"He's doing much better in that environment," Hislope said. "And we're not giving up, but it has been very, very difficult."

All of the mothers said they support the public health vaccination effort. Studies are clear; when vaccination rates decline, childhood illness increase. Reports of a mumps outbreak in Iowa highlight how necessary and important is continued vigilance against disease.

And though thimerasol has been removed from childhood vaccines, it remains in many flu shots. Children ages 2 to 5 are now recommended recipients of annual flu shots and they are routinely given to pregnant women. Thimerasol-free flu shots should be readily available upon request.

- Scott Hilyard