Vaccination (Thimerosal) and Autism: Parents, Doctors At Odds On Autism

Thousands of parents share Redwood's belief, while most of the nation's medical establishment says there is no scientific basis to believe vaccines are responsible for autism. After a lengthy investigation, the Institute of Medicine, an arm of the highly regarded National Academy of Sciences, will issue a report Tuesday that will attempt to answer an increasingly contentious question: Is there a connection between vaccines and autism?

The report takes on special significance because the number of parents refusing to have their children follow traditional vaccination schedules is on the rise. Many think the trend has been fueled by news stories, Internet sites and word-of-mouth reports of adverse effects from vaccines, the American Medical Association said.

Meanwhile, the prevalence of autism grew at a rate of 10 percent to 17 percent a year through the 1990s, before manufacturers began removing thimerosal from pediatric vaccines, according to the Autism Society of America. Today, as many as 1.5 million Americans are believed to have some form of autism, the society says. Many parents say signs of autism began to appear shortly after their children received vaccines containing thimerosal.

Although the Institute of Medicine may deliver the most complete study yet of the suspected vaccine-autism connection, it is not likely to be the last word on the issue. Many parents say they do not trust federal health agencies to tell them the truth. Meanwhile, many doctors think parents have been misled by researchers and others offering a simplistic explanation for a complex problem.

Neither side appears to be in a mood to concede.

Redwood's organization struck back quickly, for example, after the ABC News program "Primetime Live" said in a recent profile of a family with three autistic children that doctors dismiss any vaccine-autism link. "This is not only not true, but `Primetime's' assertion flies in the face of the best current research being performed by the recognized experts in this field," said Redwood, a nurse in the Atlanta area and president of SafeMinds, an organization investigating what it says are the risks caused by medical products that contain mercury.

In Connecticut, Lynne Avram, a nurse and mother of a 6-year-old autistic son, said she is not anti-vaccine but is convinced that vaccines containing thimerosal can trigger the onset of autism.

"To me this is crystal clear," the Cheshire resident said. "There's a lot of research out there that nobody's acknowledging."

Several other Connecticut mothers of autistic children expressed similar opinions.

In Missouri, parents and doctors crowded into a Jefferson City meeting hall to support legislation, sponsored by Missouri state Rep. Roy Holand. The proposed legislation calls for the state to become the first in the nation to impose a ban on vaccines that contain thimerosal. A local newspaper quoted one parent of an autistic child as saying, "This is the biggest story of the 21st century."

Vaccine supporters have begun to respond. The Sabin Institute, a vaccine think tank based in New Canaan, Conn., distributed a series of statements from parents testifying to the positive effects of vaccines. In one, a Texas mother whose son was not vaccinated and died of meningitis, said she was moved to speak out "by the loss of my only son [and] to make sure all children everywhere are protected against infectious diseases."

Dr. Louis Z. Cooper, a Columbia University professor of pediatrics and past president of the American Academy of Pediatrics, added his voice to those who urge parents to have their children vaccinated. Cooper, who has practiced medicine for 43 years, said vaccines prevent children from getting diseases that once might have killed them.

"I know how serious these diseases are," Cooper said. "I know what good vaccines do. There is no science to suggest that thimerosal plays a role in autism."

Cooper's view is shared widely, both in the United States and abroad. "There is no convincing evidence of harm caused by the small doses of thimerosal in vaccines, except for minor effects like swelling and redness at the injection site due to sensitivity to thimerosal," the Centers for Disease Control and Prevention currently advises parents in the United States.

Other organizations that downplay the risks of thimerosal in vaccines include the U.S. Food and Drug Administration, the World Health Organization and the National Health Service of Great Britain. Health Canada, a government agency comparable to the FDA, says it strongly favors continued use of vaccines containing thimerosal when no alternative exists.

The causes of autism remain elusive. Federal health officials say several studies show genetics may play a role. There is less evidence that pregnant women who consume lead or alcohol or the prescription drug thalidomide may be more likely to have autistic children, the officials say. Autism is four times more prevalent in boys than girls.

Those who believe in a vaccine-autism connection suffered a setback in February when The Lancet, an influential British medical journal, questioned the impartiality of a researcher who is a leading proponent of the theory. The Lancet took the unusual action of retracting an article Dr. Andrew Wakefield, a British researcher, co-authored in 1998 that linked the vaccine for measles, mumps and rubella, or MMR, to autism. At the time, Wakefield did not disclose that he was gathering information for lawyers representing parents who suspected their children developed autism after receiving the MMR vaccine, The Lancet said.

Wakefield, who still has many defenders, denied any conflict and has hired a lawyer. But researchers who say vaccines are safe cite the article to discredit the work of those who have a different opinion.

The setback has not shaken parents like Redwood, the SafeMinds president, who continues to lash government agencies that disagree with her organization. "It has been our long-held fear that our federal health agencies lack the desire or will to fulfill their duty in this matter," she said.

Calls for the removal of thimerosal from vaccines began with the passage of legislation in 1997 that required the FDA to identify and provide an analysis of foods and drugs containing intentionally introduced mercury compounds. Two years later the FDA said its study showed that some children over the first six months of life could be exposed to a cumulative level of mercury exceeding one of the three existing guidelines for exposure to mercury.

After the FDA study, the American Academy of Pediatrics and the U.S. Public Health Service jointly recommended in 1999 that thimerosal be eliminated or reduced in vaccines as soon as possible. Manufacturers began to comply, although it took some longer than others.

The Centers for Disease Control and Prevention says that today all routinely recommended pediatric vaccines manufactured for the U.S. market contain no thimerosal or only trace amounts. In response, critics say old stocks of vaccines containing thimerosal have never been recalled. In addition, flu vaccines routinely recommended for children still contain thimerosal.

Many parents said they also find it strange that the government has issued warnings about mercury levels in tuna fish but still allows thimerosal in some vaccines.

The debate moved to the political arena in April, when U.S. Reps. Dave Weldon, R-Fla., and Carolyn Maloney, D-N.Y., introduced legislation that would remove all vaccines that contain thimerosal from the market. Congress has yet to act on the measure.

In another development, Weldon, a medical doctor, took the concerns of many parents who distrust federal health agencies to the Institute of Medicine. At a February meeting to examine vaccine safety issues, Weldon said the CDC "has a built-in conflict of interest that is likely to bias any views" the institute arrives at in its new study. The reason, he said, is that the CDC asked the institute to prepare the vaccine safety study. Weldon repeated his concerns at a recent meeting of parents of autistic children.

Dr. Frank DeStefano, a CDC official, disputed Weldon. "We approach these studies in as objective and scientific manner as possible," DeStefano said. The committee heard from a nearly equal number of experts on both sides of the thimerosal-vaccine safety issue at the meeting.

Still, Weldon's comment reflected some parents' frustration that a 2001 institute study concluded the evidence was inadequate to accept or reject a "causal relationship" between thimerosal and the onset of autism, attention deficit disorder and speech or language disorders. Marie C. McCormick, head of the institute's vaccine study panel, has acknowledged that "some parents and researchers are concerned" about the presence of thimerosal in vaccines, but the findings of the forthcoming report remain closely guarded.

Not all parents agree about the issue. Kim Newgass, president of the Autism Society of Connecticut, said the sharp rise of autism cases should spur continued research. But she is not yet willing to point an accusing finger at thimerosal. "I think this is one of those things that is going to be up in the air for a long time," she said.

Another Connecticut woman who is the parent of an autistic child, said: "This disease, as do most, has trailing behind it an array of snake oil salesmen, flocks of lawyers with product liability complaints in hand and endless heaps of alarmists and those offering false hopes." She asked not to be identified because she said her views would put her at odds with friends who also have autistic children.

As Redwood looks at her son, she has no such doubts. "To me, the continued use of mercury [in vaccines] is almost barbaric," she said.