The murcury debate

Some parents worry that vaccinations containing mercury could do more harm than good
Sunday, January 16, 2005 | 12:00 a.m. CST; updated 12:20 p.m. CDT, Sunday, July 20, 2008

When it comes to dispensing doses of hard-to-obtain flu vaccine this winter, women and children are considered priority recipients along with the elderly.

For Lujene Clark, a southwest Missouri woman whose son is autistic, the flu vaccines are best avoided because they contain thimerosal, a mercury-containing preservative some link to the childhood developmental disease.

“We are not antivaccine,” Clark said. “The only thing we promote is that mercury is toxic.”

She helped found the NoMercury advocacy group after her son Devon, 9, was diagnosed with Asperger’s Syndrome, an autism spectrum disorder, in September 2003.

The federal Food and Drug Administration does not question the toxicity of mercury. In May 2004, the Institute of Medicine, a nonprofit think tank affiliated with the National Academies of Science, reviewed FDA research and concluded there is no direct link between vaccinations and autism.

The federal Centers for Disease Control also defends past uses of the preservative, stating on its Web site that “(h)igh rates of vaccination led to declines of 95 percent to 100 percent in the occurrence of vaccine preventable diseases.”

Concern over thimerosal in the past several years led vaccine manufacturers to discontinue manufacturing doses of childhood immunizations containing the ethyl mercury compound. Drug companies were not required to label vaccines as containing mercury until January 2004, meaning some doctors could be dispensing doses with thimerosal.

A sizable number of parents consider the risks of mercury-induced developmental diseases, coupled with the remote chance of contracting polio, measles, mumps, rubella, diphtheria, hepatitis B and other communicable ailments for which most children are now vaccinated, sufficient to not vaccinate their children.

In the Columbia Public Schools, an average of 70 students for each of six vaccines has filed religious exemptions that allow them to attend school without having received the legally mandated immunizations. Another 19.67 students, on average, have medical exemptions for those required vaccines, said Susan Robinson, the district’s health services coordinator.

Because students and parents do not have to indicate a reason for their opposition, it is not clear how many of those families are concerned about the mercury-autism link.

Critics of thimerosal, a compound that is 49 percent mercury, cite new evidence that disputes the results of the FDA study.

Last month, the Environmental Working Group think tank released the results of an 18-month investigation that recommends allotting more federal money to explore the link between thimerosal and autism.

The environmental group based its findings on new research Dr. Jill James, a pediatrics professor at the University of Arkansas for Medical Research, conducted.

James, also a former senior research scientist for the FDA, found evidence that autistic children have a deficiency in glutathione, the body’s main defense against neurotoxins such as mercury that enter the body.

Thus, exposing children to high levels of mercury and other neurotoxins could make them more susceptible to brain damage and cause autism, the study concludes.

In a subsequent interview, James cautioned that the study doesn’t prove a causal relationship between thimerosal and autism.

“But to put mercury in children just is not a good idea,” she said. “If I was pregnant, I wouldn’t want any mercury exposure. Prudence would suggest none.”

In Missouri, state Sen. Norma Champion, R-Greene County, and Sen. Jacob E. Crowell, R-Cape Girardeau, have filed bills in the 2005 legislative session to ban immunizations containing mercury preservatives by 2007. Similar measures have been approved in California and Iowa.

Similar legislation passed the Missouri House of Representatives 152-4 last year but former Sen. Ken Jacob, D-Columbia, filibustered it in the state Senate. Jacob, who is no longer in office, could not be reached for comment to discuss his opposition.

Those who support the use of thimerosal cite their studies, as well the federal government’s blessing. Without a preservative like thimerosal, they insist, there would not be enough flu vaccine to go around.

“Providing everyone with a thimerosal-free dose of the vaccine is currently not possible,” said Sue Denny, a spokeswoman for the Missouri Health Department. “Even if we could, the costs would rise dramatically.”

Denny said the department supports the FDA conclusion that no evidence supports the theory that thimerosal causes autism.

Many consider autism to be an epidemic. Data from the American Academy of Pediatrics shows an increase in the rate of autism from six in 10,000 children in the 1980s to 60 in 10,000 today.

In Missouri, the number of autistic children attending public school nearly doubled from 1999 to 2004, according to special education data the Missouri Department of Elementary and Secondary Education collected.

James said she believes some of the increases can be attributed to the liberalized criteria of what constitutes an autism spectrum disorder.

“They have broadened the diagnostic criteria,” James said. “But there’s research that clearly shows that it is a real increase.”

James said the rise in autism coincides with the FDA’s decision in the early 1990s to increase the number of childhood vaccinations containing thimerosal. She said the FDA didn’t realize that by increasing the number of vaccines children were being exposed to more mercury, but when it did, the agency began encouraging drug makers to produce thimerosal-free vaccines.

The FDA Web site acknowledges “urging vaccine manufacturers to reduce or eliminate thimerosal in vaccines as soon as possible” in 1999 and 2000 but denies that thimerosal causes autism.

The agency also lists a breakdown of pediatric vaccines by thimerosal content. The flu vaccine is the only one that contains more than a trace of mercury, and its concentration of thimerosal has been significantly lowered over the past decade.

While the debate over vaccines rages, James has developed a way to treat autism that doctors in Missouri are using. She said doctors across the country are using methyl B-12, a compound that is typically ground by a pharmacist and injected, to help restore autistic children’s deficit in glutathione. The results have not been scientifically verified, she said.

Clark, a Carthage resident, said her son receives methyl B-12 shots three times a week and is making a recovery. He also receives inferred sonar to get the mercury and other metals out of his system.

“He’s making better grades. He’s more mainstream in school,” Clark said. “His overall health has improved, and he’s gaining weight and stature at an age-appropriate level now.”

Denny said most pregnant women and children older than 3 will receive versions of the flu vaccine that contains thimerosal this winter. The limited number of thimerosal-free flu vaccines, which do not come in an adult version, are mostly reserved for children younger than 3.

Denny said she feels for parents whose children have autism and doesn’t blame them for looking for answers. She’s afraid that a ban on thimerosal will only lead to more shortages, higher prices for flu vaccinations and more cases of influenza.

“Most physicians would prefer to have one kind of the vaccine because it’s a lot more convenient, less expensive to carry and reduces the opportunity for making an error,” she said.

Sonia O’Donnell, deputy director of outreach services for the Central Missouri Autism Project, says the medical community disregards any correlation between mercury in vaccines and autism.

“The medical community says you have to look at the public health interests, and if we have to sacrifice this child for the whole community, then that’s what we need to do to keep people healthy,” she said.

Missourian reporter Jessica Luck contributed to this report.

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