WASHINGTON, Feb. 9 (UPI) -- As doctors and health authorities fight state bans on mercury in vaccines and keep giving it to kids and pregnant women, one fact stands out: their certainty.
The image of pediatricians and public officials as valiant defenders of mercury takes a bit of getting used to, given their longstanding efforts to keep the toxic element out of our food, our bodies and the environment.
No reasonable person -- let alone health professional -- would advocate keeping mercury in childhood vaccines unless they were absolutely certain it was an exception to this lethal legacy.
That's especially so because vaccines can be made without the mercury preservative, called thimerosal. You can take it out and still protect the health of American children through vaccination, and if you had a shred of doubt about its safety, surely you would.
If you keep it in, you had better be right.
But what is the real degree of certainty that thimerosal is safe? Is it absolute? Beyond a reasonable doubt? A preponderance of the evidence -- the lesser standard that applies in civil cases but not when someone's freedom (or life) is at stake?
Here's the kind of thing that makes doctors -- most of whom have no more ability than you or I to investigate the safety of vaccines for themselves -- feel so certain. It's a paper titled "Vaccine Safety Controversies and the Future of Vaccination Programs," and it appears in the November 2005 issue of The Pediatric Infectious Disease Journal.
The authors are from the U.S. Centers for Disease Control and Prevention, which recommends the childhood immunization schedule; the United Nations World Health Organization, which oversees the vaccination of tens of millions of people worldwide every year, and several big universities. The report was supported by "unrestricted grants from GlaxoSmithKline Biologicals, Sanofi Pasteur MSD, several universities and other institutions."
"Thimerosal has been used for (more than) 60 years in infant vaccines and in other applications and has not been associated with adverse health effects in the general population, except when persons have been exposed to amounts many orders of magnitude greater than found in vaccines or pharmaceuticals," the authors write.
That's a ringing endorsement of safety (whether it's supported by the data is an issue I'll address in upcoming columns). But keep reading: "It should also be borne in mind that the risks of thimerosal-containing vaccines to the fetus, premature infant and low-weight infant have insufficiently been studied."
Whoa. "Insufficiently studied" -- after more than 60 years of giving thimerosal to pregnant women and babies of every size and shape? Nonetheless, the CDC recommends flu shots for pregnant women and 6-to-23-months-olds and won't recommend thimerosal-free versions. As a result, most flu shots still contain mercury.
Another new study is condescendingly titled, "When science is not enough -- a risk/benefit profile of thimerosal-containing vaccines," by Australians C. John Clements and Peter B. McIntyre in the journal Expert Opinion on Drug Safety:
"Thimerosal is safe as a vaccine preservative, and should continue to be used in settings where accessibility and cost require that multi-dose vials of vaccine are available."
Clements advises the WHO on vaccine policy; McIntyre is director of Australia's National Center for Immunization Research and Surveillance of Vaccine-Preventable Diseases.
"The overwhelming weight of scientific opinion rejects the hypothesis that neurodevelopmental abnormalities are causally related to the use of thimerosal in vaccines," they point out.
This is the kind of ammunition public health officials and the American Academy of Pediatrics are firing back at proponents of mercury bans --"overwhelming" evidence that thimerosal is safe. In Illinois, the state AAP vigorously opposed the ban.
"Though well intended, these bills do not advance public health and could inadvertently diminish our state's efforts at fighting influenza," the AAP said. "Though it is a mercury-containing compound, thimerosal does not pass from the bloodstream into the brain to any significant degree."
The state legislators listened politely to that dubious assertion -- and voted to limit thimerosal in childhood vaccines anyway. But that was not the last word.
As reported by R. L. Nave in the Illinois Times last month: "Citing cost concerns and a potential shortfall for the upcoming flu season, the Illinois Department of Public Health filed for a 12-month exemption to the Mercury-Free Vaccine Act, passed last summer to limit the use of vaccines containing mercury. However, child-health-care advocates who lobbied for the bill's passage are upset by what they believe was a premeditated attempt by IDPH to circumvent state law."
This is what you call chutzpah -- public health authorities thwarting the express will of the people, certain that flu shots will save humanity and mercury never hurt anybody. Does the governor never fire anyone?
Almost lost in this crossfire is the simple fact that in 1999, these selfsame health authorities -- the CDC, the Public Health Service, the pediatricians, the family physicians -- urged drug companies to remove thimerosal from childhood immunizations in the United States as soon as possible.
Most childhood vaccines -- in the United States, not overseas -- are now thimerosal-free. But that's hardly a blanket reassurance, because most flu shots do contain thimerosal.
Yet the CDC is still studying whether thimerosal causes autism.
"We do agree the preponderance of evidence to date suggests there is no association between thimerosal and autism," CDC spokesman Glen Nowak told us last month. But he said CDC Director Dr. Julie Gerberding is committed to exploring all possibilities until the cause or causes of the disorder are identified.
"Dr. Gerberding has made it clear the CDC has not ruled out anything as possible causes of autism, including thimerosal," Nowak said. "Science is a dynamic process. We have continued to fund studies to look at the role, if any, of thimerosal."
Given these caveats, what would you do? Well, there are two maxims of medicine that might apply. "First, do no harm," is the obvious one.
The second, related concept is the precautionary principle which, according to wikipedia.org, "is the idea that if the consequences of an action are unknown, but are judged to have some potential for major or irreversible negative consequences, then it is better to avoid that action."
So: Vaccines don't need mercury. Even government experts acknowledge some possible risks -- to the fetus, for example -- are insufficiently studied 60 years on. A link to autism has not been ruled out. They're continuing to investigate, as they should.
But the doctors and their public and private allies are battling state by state to stop mercury bans, and the CDC won't recommend a thimerosal-free flu shot for kids and pregnant woman. There's a phrase for this approach: