Federal hearing rekindles thimerosal-autism debate

As has been widely covered in the media, a significant hearing is underway in Washington, DC, this month, as three Special Masters hear claims from a group of 5,000 plaintiffs alleging a link between thimerosal-containing vaccines (prior to the preservative's removal in 1999) and autism. Directly at stake is whether autism should be included among diagnoses for which compensation can be awarded through the federal government's Vaccine Injury Compensation Program. Advocates of vaccination warn that a ruling in favor of the plaintiffs could bankrupt the compensation program, resulting in dire consequences for U.S. vaccination efforts.

The overwhelming consensus among the medical community remains that no link can be found between thimerosal and autism. (Here's the CDC site on mercury and vaccines.) Critics of this view -- many of whom have close links to children or families affected by autism -- respond that these conclusions are based on flawed or inadequate research, or worse, are the product of a medical and vaccination community with unacceptably close ties to the pharmaceutical industry.

Official information along with audio and transcripts of the proceedings can be found here.

An excellent preview of the proceedings appeared in this story by Shankar Vedantam in last Sunday's Washington Post.

Gardiner Harris of the New York Times reported here on the first day of testimony last Monday, as did this AP story. Over at Slate, Arthur Allen previewed the hearing, and the New Scientist reports on it as well. Both focus on the widely criticized research of Dr. Mark Geier -- undoubtedly the most controversial proponent of a thimerosal-autism link.

Sharyl Atkinson of CBS News offered some very provocative opinions in a web column titled, "Autism: Why The Debate Rages." In the Boston Globe, Paul Offit weighed in via an op-ed titled, "At risk: vaccines -- How a legal case could cripple one of modern medicine's greatest achievements". Offit's op-ed generated a number of critical letters which the Globe printed here.

An interesting sidebar to these proceedings is the reported rift among the autism advocacy community regarding the merits of thimerosal-based explanations for the rise in autism rates vs. other potential explanations. Both the New York Times ("Autism debate strains a family and its charity") and ABC News ("Emotions run high over autism's causes") highlighted the disagreement between members of the Wright family, founders of Autism Speaks, perhaps the most prominent and well-connected autism organization. At The Huffington Post, Robert F. Kennedy, Jr., takes issue with these portrayals of Katie Wright, who believes strongly in a thimerosal-autism link.

The hearing in Washington is scheduled to continue for another week and a half; a decision may take a year.

Caplan on autism and vaccines

Our own Art Caplan weighs in on the increasingly hard to discount evidence rejecting a link between thimerosal (once included in vaccines) and the increasing prevalence of autism in children. (The short explanation: autism rates continue to rise years after thimerosal's removal from vaccines, suggesting very strongly -- if not proving -- that other factors are responsible.)

In today's Philadelphia Inquirer, Caplan writes in an op-ed titled "Fact: No link of vaccine, autism":

"This nation's future, its national security, the safety of its health-care institutions, and the safety of its citizens depends upon vaccination. It is way past time that message got heard by parents, teachers, nurses, doctors, hospital administrators, the media and politicians. If there has been a more harmful urban legend circulating in our society than the vaccine-autism link, it is hard to know what it might be. At a time when vaccines may be our last best hope in facing some of the greatest challenges we and our children face, this legend needs to be put to rest. Vaccination, not vaccine-bashing, is what this nation needs."

The continued focus on a vaccine link to autism (at the expense of other research directions) has long been a source of tension among many in the autism advocacy community. Even with this news, however, signs point to critics of U.S. vaccination policy continuing to argue that vaccines are still somehow linked to autism, via as an-yet-unknown alternate mechanism now that thimerosal is no longer a likely candidate. For more on this shift in strategy, see this post by Barbara Loe Fisher.

"Autism controversy eats at credibility of CDC"

Thursday's Atlanta Journal-Constitution (registration required) has a very good story detailing some of the recent developments in the continuing vaccines and autism controversy. As to the validity of such a link, there's no news and still no evidence to support it, according to the American Academy of Pediatrics and the CDC, among many others. But renewed interest and support from members have Congress have redirected attention to the topic, which by itself has an impact on vaccination, as the story explains...

"As the debate and controversy increasingly finds its way into pediatricians' offices, average parents of healthy children are questioning whether vaccines are safe, sometimes even refusing inoculations.

The CDC and other public health officials insist such questions lack a basis in fact or science. Their greatest concern is that the broadening debate holds the potential to put a new generation of children at certain risk of deadly diseases if confidence in the safety of vaccines is lost and they don't receive recommended shots.

'I think it's huge,' said Dr. Julia McMillan, a member of the American Academy of Pediatrics committee that makes vaccine recommendations. 'There's no pediatrician in practice that doesn't confront this on a weekly basis: families who are questioning the need for – and in some cases refusing — vaccines for their children.'"

Yesterday's USA Today featured a full page ad paid for by several autism advocacy groups which cites Robert F. Kennedy's comments on the CDC last month (which we wrote about here) and links to the website www.putchildrenfirst.org. That site, which includes links to numerous CDC documents, memoranda, and e-mails, describes its mission as follows...

"In our efforts to share the truth with other parents, we have been frustrated by the amount of misinformation in the press stating that the connection between mercury and autism has been disproven. This website was constructed to share the truth about what 'proof' actually means.

The National Immunization program (sic) is at risk. The CDC through the choices made, has eroded public trust. Autism is a national emergency and a national shame. We need independent journalists and members of Congress to take action now and put our children first."

In the AJC, the CDC responds... "CDC spokesman Glen Nowak said many of the documents on the site have been in the public domain for years, and are presented out of context and in ways that may 'look quite ominous' – when they're not." Regarding the USA Today advertisement, the CDC released this response, expressing 'disappointment' at how their (and others') efforts were characterized.

Finally, the Vaccine Education Center at the Children's Hospital of Philadelphia recently updated its page on "Thimerosal and Autism."

More on thimerosal...

With a headline sure to amaze those who don't read the full story, the MetroWest Daily News (part of the Boston Herald family) proclaims, "Study links autism, vaccine." If this were even the least bit true, one suspects the MetroWest Daily News wouldn't be the only media outlet covering the story.

Rather, the story here is in reference to a paper published in the Journal of American Physicians and Surgeons titled "Early Downward Trends in Neurodevelopmental Disorders Following Removal of Thimerosal-Containing Vaccines."

The story explains:

"Autism diagnoses have dropped nationwide since mercury was removed from most childhood vaccines, according to a new study that some say lends credence to charges that vaccinations were responsible for a huge increase in autism cases. "

The paper in questions uses state and federal databases that track autism prevalance as well as VAERS, the Vaccine Adverse Event Reporting System. All of these sources have significant data reliability concerns, which, to the newspaper's credit, are noted in the story.

For example, adverse events can be reported to VAERS by anyone and are not verified for accuracy. This paper in Pediatrics (subscription required) -- Goodman, M.J., and Nordin, J. "Vaccine Adverse Event Reporting Source: A Possible Source of Bias in Longitudinal Studies." Feb. 2006; 117: 387-390 -- finds that most thimerosal-related reports to VAERS were directly related to pending litigation. The authors specifically warn researchers attempting to use VAERS data for studies such as the one above about the serious questions regarding its reliability.

RFK Jr.'s latest on thimerosal

Over at The Huffington Post, Robert F. Kennedy Jr. declares that it's "Time for the CDC to Come Clean" about the events leading to the decision in 1999-2000 to remove thimerosal from childhood vaccines. An excerpt:

"But newly released documents show that behind the scenes CDC was quietly discouraging Thimerosal's removal. In a July 1999 letter, vaccine producer SmithKline Beecham tells CDC that it is ready to produce non-Thimerosal DTP (Diptheria/Tetanus/Pertussis) vaccines immediately and has sufficient inventories to supply the entire U.S. market during the remainder of 1999 and the first half of 2000, by which time other vaccine manufacturers would have their Thimerosal-free DTP vaccines on line.

Thimerosal-laden DTP vaccines containing 25 micrograms of mercury apiece were then being administered to American infants at two months, four months and six months -- far exceeding EPA's recommended safe level for mercury. Had CDC accepted SmithKline's offer, it could have immediately reduced the mercury exposures to vaccinated six-month-old children by 40%.

However, in November, CDC mysteriously sent a letter back rejecting SmithKline's offer. Then, on July 14, 2000 CDC published a deceptive press release promising to require that all vaccines be Thimerosal-free as soon as "adequate supplies are available." This was a full 12 months after the agency had denied SmithKline's proposal.

"If CDC were basing its decision on safety alone, it would have taken SmithKline up on its offer. That's a no-brainer," said a federal health official who requested anonymity. "So there were other considerations beside safety that were guiding their decision making."

Among these "other considerations" were CDC's important concerns for the preservation of the vaccine program, a bureaucratic impulse for self-preservation, and protecting the economic interests of its vaccine industry friends."

While the thimerosal/autism stories have generally faded from the media spotlight (except for a few places, such as Imus, etc.), RFK Jr.'s post and many of the comments that follow it illustrate how strong the passions remain among those certain that a link exists and that the government and vaccine industry covered it up for financial gain.

There's little use reviewing here the arguments of both sides in this debate. What all could probably agree on is that the CDC decision to remove thimerosal in 2000 sent a mixed signal, since the evidence then (and now) cited by the medical community continues to show zero evidence of a link to autism. 'If the evidence is so clear, why call for its removal?' is a reasonable question to ask. What seemingly was an attempt to end the controversy by removing a non-essential ingredient has actually had the reverse effect, increasing skepticism and thoughts of conspiracy among those inclined to think in such a way. Years later, the controversy continues to simmer in many, as RFK Jr.'s comments illustrate.