Vaccination opponents intentionally try to confuse parents over the one type of mercury found in fatty fish and the other type found in thimerosal. But now scientists are saying even the type in fish may not be as worrisome as once thought.
Thimerosal, used in vaccines since the 1930s, comprises about 50 percent ethyl mercury. It neither contains nor degrades into the pollutant methyl mercury that pregnant mothers are warned about in fatty fish. (That said, the Maternal Nutrition Group, a coalition of nutrition groups and experts including several federal agencies, has just released a report calling on pregnant women to eat far more fatty fish than they do, citing in part a low risk from methyl mercury.)
The thimerosal fearmongers comprise three groups.
The first is the far left as represented the Environmental Working Group and individuals like environmental crusader Robert F. Kennedy Jr. Second, there is the old anti-fluoridation far right, as represented by the Association of American Physicians and Surgeons, Inc (AAPS). Third are parents of autistic children. Strange bedfellows, indeed!
In this latest study, Centers for Disease Control and Prevention researchers evaluated more than 1,000 children between the ages of seven and 10 who were exposed to various levels of thimerosal at various early stages in life. They made almost 400 different statistical comparisons.
"We assessed children on 42 neuropsychological outcomes and found few significant associations with exposure to mercury from vaccines and immune globulins administered prenatally or during the first 7 months of life... The associations that we detected were small, almost equally divided between positive and negative effects, and mostly sex-specific."
It was not a study of autism, but a multitude of earlier studies have specifically looked for a thimerosal-autism link and found none. In a 2004 214-page summary of them, the Institute of Medicine concluded: "The evidence favors rejection of a causal relationship between thimerosal-containing vaccines and autism."
Unfortunately, back in 1999 federal health officials caved into activist demands. While reaffirming that evidence indicated thimerosal was safe, they nonetheless "urged" the removal of anything but trace amounts of the preservative from childhood vaccines. This was accomplished in 2001 although the last of the stocks werent used up until January 2003. (Flu shots still contain the ingredient.)
Nevertheless, this has allowed an interesting way of assessing the thimerosal-autism connection, in that ending use of such vaccines should be followed by a drop in cases.
California has become a statistical battleground, presumably because of data collected from the states Department of Development Services and provided online in its FactStats quarterly reports. Blogged David Kirby at the Huffington Post in 2005, "If the numbers [of autism cases] in California and elsewhere continue to drop – and that still is a big if – the implication of thimerosal in the autism epidemic will be practically undeniable."
Problem is, they werent dropping.
Playboy Playmate Jenny McCarthys authority on autism would appear to stem from her 38 C IQ.
Health professionals (and often federal courts) have harshly dismissed the Geiers work, with the American Academy of Pediatrics condemning them for "numerous conceptual and scientific flaws, omissions of fact, inaccuracies, and misstatements." Further, California isnt our only test case. Published studies have also shown a continued increase in autism after thimerosals removal from vaccines during the 1990s in Sweden, Denmark, and Canada.
But the general public is essentially ignorant of all this. "It doesnt seem to matter what the studies and the data show," Kristen Ehresmann, a Minnesota Department of Health official told The New York Times. "And thats really scary for us because if science doesnt count, how do we make decisions? How do we communicate with parents?"
One reason for the public ignorance, unfortunately, is that precautionary "ban." Many health professionals now regret it. "The removal of thimerosal created the impression of risk, where none existed," Dr. Paul Krogstad professor in the departments of pediatrics and medical pharmacology at the David Geffen School of Medicine at UCLA, told ABC News Online.
But a much more important reason is deliberate disinformation. There are over 150 anti-vaccine web sites. And who cares what a multitude of studies say when former Playboy Playmate Jenny McCarthy claims on Oprah and in the new book shes hawking that her son got autism from a vaccine?
Activists also fiercely target the MMR vaccine (measles-mumps-rubella), insisting it, too, causes autism – though MMR never contained thimerosal. (This is the vaccine Jenny McCarthy blamed.) Like fluoridated water, theres a segment of our society that sees childhood vaccines as some sort of black magic.
The AAPS claims to only oppose ”mandatory vaccines, ” even as its efforts scare parents away from having their children vaccinated voluntarily.
Moreover, only mandatory programs can confer ”herd immunity, ” meaning that immunization rates in the wider population are high enough (for example, 85 percent for diphtheria) to protect those not immunized.
Those who encourage parents to avoid vaccinating their kids are telling them to become free riders, relying on those parents who do vaccinate. But if enough people try to free ride, then herd immunity is lost and what follows is the return of childhood diseases we hardly think about anymore. Diseases like pertussis have made comebacks in countries as diverse as Australia, Japan, and Sweden after anti-vaccinationist scares.
Better known as ”whooping cough, ” pertussis is a highly contagious bacterial disease that causes uncontrollable, violent coughing. You can hear it here. Pertussis cases went from fewer than 8,000 in the U.S. in 2001 to over 25,000 in 2005.
Any vaccine will cause some side effects if given to tens of millions of people. But theres no evidence that any vaccine has ever caused a single case of autism. Scaring parents – including when its parents scaring parents – is unconscionable. "Suffer the little children" should not become a working principle.