Friday, April 01, 2005

A shot to the Hull

Posted by Craig Westover | 4:33 PM |  

In the March 29 Pioneer Press, Minnesota state epidemiologist with the Minnesota Health Department Dr. Harry Hull responds to a couple of my columns on the possible vaccine/mercury/autism connection. Below is his column fisked with my response.


Twice in recent months (Feb. 9 and March 16), columnist Craig Westover has done your readers a great disservice by alleging mercury in childhood vaccines causes autism. The sources he has cited have been far from as "objective" and "unbiased" as he has claimed. Westover clearly has not looked at all the facts and available information on the subject. While the actual causes of autism are unclear, the overwhelming body of scientific research says mercury in childhood vaccines does not cause autism.

So, what is Dr. Hull's evidence that my sources are not objective and unbiased? They have looked at the facts and drawn a conclusion. Is that the new definition of biased? To make a judgment?

No, I have not looked at all the information, but I have looked at the boxes full of information that litter my office -- information on both sides of the issue, for, as I wrote, I was very skeptical going into the research that there was a connection outside the mind of a few conspiracy theorists.

No, not all, but I have looked at enough to know that there is good science that has forced even the Institute of Medicine (IOM) to admit there is “biological plausibility" for a connection and there is virtually no hard scientific evidence and certainly no overwhelming body of scientific research that disproves a connection between mercury and childhood vaccines and autism. What there is are a plethora of denials and studies attempting to discredit the science of honest researchers painstakingly working along the path from hypothesis to theoretical justification to hard science plausibility to (and not there yet) definitive causal connection.

One of the clearest pieces of evidence that we have is that in Denmark, when thimerosal (the mercury-containing compound previously used as a preservative in vaccines) was removed from all childhood vaccines 10 years ago, autism rates continued to rise sharply, even among children 2 to 4 years old who received only mercury-free vaccines.

Let’s examine Hull’s statement before we look at the Danish study. If thimerosal were safe, why did the Danes remove it from vaccines in 1992, seven years before it was suggested that it be removed in the United States? That aside, some important considerations of the Danish study.

First, I had the opportunity to spend almost two hours with Dr. Boyd Haley when he was here to testify before the Minnesota Senate Health and Family Security Committee. Dr Haley is chairman of the Department of Biochemistry in the College of Pharmacy at the University of Kentucky Medical Center. He researches and lectures on the relationship between mercury exposures and neurological diseases like Autism and Alzheimer’s Disease. He has authored and published numerous articles on the effects of mercury toxicity and its link to autism and is on the scientific advisory board of the National Autism Association.

Speaking of the Danish study, Dr. Haley pointed out that to compare the situation in Denmark in 1992 with that of the United States in 1999 was just plain bad epidemiology. To wit: Dr. Mark Geier and his son David, who did initial analysis on the possible relationship between mercury dosages and autism using CDC data, also analyzed the Danish data. They found that the amount of thimerosal in the vaccines used in Denmark in 1992 and the number of vaccinations given to each child produced significantly less mercury exposure than received by children in the United States. In combination, it was the amount typically injected into infants in the United States in the 1970s, before the beginning of the dramatic increase in autism diagnosis.

Further analysis by Safe Minds, a private nonprofit organization founded to investigate and raise awareness of the risks to infants and children of exposure to mercury from medical products, including thimerosal in vaccines, found problems with the Danish database. The data was collected such that it was biased toward younger children, which skewed the results in favor of the interpretation of non-linkage of thimerosal and autism.

Safe Minds reanalyzed the Danish registry data, eliminating the bias, and found 2.3 times as many autism cases among the 1992 thimerosal exposed group than among the 2002 non-thimerosal exposed group. The autism incidence rate for the thimerosal-exposed group was approximately 1 case in 500 births, three times greater than for the 2002 cohort, but more important to the question of credibility, right in line with the 1 in 500 ratio in the UK and the 1 in 250 ratio calculated for the United States when compared to similar cohorts receiving similar dosages of mercury.

It may be argued that Safe Minds data is tainted by its perspective, which certainly the organization did not try to hide. It’s interesting (even to us conspiracy theory skeptics) that the Danish study and studies done in the United Kingdom, even though they had no apparent CDC funding connection, the CDC was covertly influencing the funding of these studies that, in theory, they had nothing to do with. I have a copy of a letter from the CDC that supports expediting publication of these studies in the Journal of Pediatrics.

Despite all that, I would not dispute that there might be validity in the Danish study worth examining. The point is, Dr. Hull wants to call it a “clear piece of evidence,” which it clearly is not. He expresses the very non-scientific attitude that all questions are answered and there is no further need for research, which is the “ineffectual bureaucratic response” that is referenced below.

Westover asserts that those in public health are "unresponsive bureaucrats" with their feet stuck in the mud who don't care about the suffering of people. Nothing could be further from the truth. The people who I have the great fortune to work with every day in public health are driven by their compassion and concern for the well-being of others. Their work is guided and informed by the best available science, and they are constantly reassessing their work based on new evidence.

If Dr. Hull’s science is as confused as his reading of plain English, then it is little wonder that he regards the Danish study as clear evidence. Here is what I wrote in my column --

But the parents' fight is more than just another David versus Goliath story. There is a third level on which one can read "Evidence of Harm." Regardless of one's belief or even interest in a mercury-autism connection, "Evidence of Harm" is a devastating picture of ineffectual bureaucratic response to urgent concerns of the very people the system is intended to serve.
Indeed, the thimerosal/autism story is one of “ineffectual bureaucratic response.” But nowhere have I written or implied the characterization of any individual as having “their feet stuck in the mud who don't care about the suffering of people.” In fact, what I wrote about individuals was --

The notion that vaccines might cause harm, even to a minority of kids, "threatens the very core of what these bureaucrats believe in," Kirby quotes the father of an autistic child as saying. "The whole apparatus is there to do good. . . .The notion that [vaccinations] are harmful is unthinkable [to them]."
In other words, these are (in general, for I am coming around to the belief that there are some bad guys here) good people trying to do the right thing. So strong is their belief in the rightness of their actions, that they can’t imagine their actions leading to a bad result -- that’s not evil nor even stubbornness; it’s simply misguided. The system is what’s at fault here, not the people.

Westover's accusation of unresponsiveness is hard to fathom because all but the tiniest traces of mercury were removed years ago from the vaccines routinely given to infants. There is even a mercury-free version of influenza vaccine for children older than 6 months of age. Mercury-free vaccines were developed because of our concerns that parents' fears of the mercury in the vaccines, however unfounded, would lead them to not immunize their children.

Unresponsiveness? We’ve already mentioned the fact that Denmark removed thimerosal from childhood vaccines in 1992. (I am assuming that "tiniest traces" is a precise scientific measurement with which I, a mere layman, am not familiar. It was mere "small amounts" that when added together produced dosages of mercury in children many times the EPA average for safe exposure.)

Let’s look at some other dates on the thimerosal timeline as compiled from various sources including David Kirby and Mother Jones Magazine.

1950 -- A New York Academy of Science article, “Mercurials as Antiseptics” says merthiolate (thimerosal) “is toxic when injected peremptorily and cannot be used in chemotherapy.”

1967 -- Eli Lilly’s Medical Science department requests that the claim “non-toxic” on thimerosal labels be deleted in the next print run.

1972 -- Lilly received information that merthiolate in vaccines caused six deaths suggestive of mercury poisoning.

1974 -- Lilly stops manufacturing vaccines with thimerosal, but continues to manufacture thimerosal for resale.

1976 -- Lilly objects to Rexall Drug Company’s efforts to place a warning on thimerosal regarding mercury poisoning claiming that it contains organically bound ethyl mercury that is non-toxic in nature.

1980 -- FDA begins review of over-the-counter (OTC) products containing thimerosal.

1982 -- FDA proposes a ban on thimerosal in OTC ointments citing possible toxicity and ineffectiveness.

1983 -- Warning to pregnant and nursing women added to some labels of thimerosal-containing products.

1991 -- Lilly ceases manufacture and sale of thimerosal. Licensing guarantees profits until 2010.

1991 -- The CDC’s Advisory Committee on Immunization Practices adds Haemophilus Influenzae B (Hib) to its recommendations for childhood immunization. Ten months later, the CDC recommends Hepatitis B vaccinations for children. Both use thimerosal as a preservative.

1991 -- Merck Pharmaceutical executives aware of increased exposure to mercury from additions to childhood vaccination schedule, but do not make the information public.

1997 -- Congress passes the Food and Drug Administration Modernization Act that requires the study of mercury content in FDA-approved products. The review reveals the previously unrecognized high levels of ethylmercury in the recommended vaccination schedule.

1998 -- FDA’s proposed ban on thimerosal in OTC products takes affect.

1999 -- Some public-health experts publicly advocate the removal of thimerosal from vaccines based on studies of neurological problems in babies whose mothers ingested mercury while eating whale blubber during pregnancy. Study is source of EPA recommend limit for exposure to mercury.

1999 -- Public health officials announce that thimerosal will be phased out of vaccines, insisting the move is only precautionary.

1999 -- Congressman Dan Burton (R-Ind), then chairman of the House Committee on government Reform, begins hearings for what will become a three-year investigation into autism and its possible causal link to vaccines. Federal agencies confirm that autism affects 1 in 500 children in the United States.

1999 -- CDC researcher Thomas Verstraeten’s unpublished analysis of CDC Vaccine Safety Datalink records finds a relative risk of 7.6 for autism in children that receive thimerosal-containing vaccines. (Note: Generally a relative risk of 3.0 is considered the threshold to demonstrate causality. For comparative purposes, the best relative risk I have seen for a Government-sponsored study of secondhand smoke as a cause of cancer is 2.69, which people take as “conclusive.”)

2000 -- First reanalysis of Verstraeten’s data yields a relative risk of 2.48. Verstraeten discloses his results to vaccine advisory committee at Simpsonwood meeting and the relative risk drops to 1.69. The committee decides not to state a preference against thimerosal-containing vaccines.

2000 -- Safe Minds forms to "investigate and raise awareness of the risk to infants and children of exposure to mercury through medical products, including thimerosal in vaccines."

2001 -- Sallie Bernard and Lyn Redwood (Safe Minds) publish "Autism: A Novel Form of Mercury Poisoning" in the journal Medical Hypotheses. The paper makes the case for a causal link between mercury and autistic spectrum disorders.

2001 -- The CDC's vaccine advisory committee again decides not to state a preference for thimerosal-free vaccines. By this date, diptheria-tetanus-pertusis (DTaP), Hepatitis B, and Hib vaccines manufactured for the U.S. market no longer contain thimerosal. Thimerosal-containing vaccines that have not yet expired may remain on doctors' shelves.

2001 -- A second IOM report finds insufficient evidence to either accept or reject a causal relationship between thimerosal-containing vaccines and neurological disorders, but says the "hypothesis is biologically plausible."

2002 -- Proceedings looking into the causal link between thimerosal and autism begin in the federal vaccine court. This is the first step in the legal process for parents seeking compensation for alleged adverse effects of vaccines on their children.

2002 -- The FDA has estimated this as the final expiration date for thimerosal-containing HepB, Hib, and DTaP vaccines. A California study finds that a three-fold increase in classic autism diagnoses in the state between 1987 and 1998 is real, and cannot be explained as a result of improved diagnostic techniques and case-finding.

2002 -- Congressional Republicans insert language into the 475-page homeland security bill that would prevent parents from suing vaccine makers. After public outcry, the proposal is scrapped in January 2003.

2003 -- A CDC study finds a ten-fold increase in autism rates in Atlanta between the 1980s and 1996. Some researchers now estimate 1 in 150 children have autistic spectrum disorders.

2003 -- An analysis of CDC vaccination data finds that children who received thimerosal-containing had a higher risk of autism.

2003 -- The House Committee on Government Reform's report on its investigation assails public-health officials and pharmaceutical companies for failing to remove ethylmercury, "a potent neurotoxin" from medical products. The report concludes: "Our public health agencies' failure to act is indicative of institutional malfeasance for self-protection and misplaced protectionism of the pharmaceutical industry."

2003 -- Verstraeten's analysis is published in a peer-reviewed journal, Pediatrics, setting off a new wave of controversy and accusations of statistical manipulation. Congressman Dave Weldon (R-Fla.) writes to CDC Director Julie Gerberding to open up the agency's vaccination database to independent researchers.

2003 -- A national autism summit is held in Washington D.C. to discuss an interagency effort to researching the causes and possible treatments for autism.

2004 -- A joint statement by the AAP, American Academy of Family Physicians, the CDC vaccination advisory committee, and the Public Health Service maintains that "there remains no convincing evidence of harm caused by low levels of thimerosal in vaccines."

2004 -- A panel sponsored by the Institute of Medicine announces there is no link between vaccines and autism.

I have left out a number of studies by Dr. Boyd Haley of the University of Kentucky, Mady Hornig, M.D., Columbia University, New York, NY, Richard Deth, Ph.D., Northeastern University, Boston, MA , Dr. Jeff Bradstreet, Palm Bay (Orlando), FL, and Bernard Rimland, Ph.D, San Diego, CA that advance both the theoretical and the hard science supporting a possible connection between thimerosal in vaccines and autism and other neurological disorders.

Take all of that together and even to a layman, doesn’t it seem that at some point trained professionals such as Dr. Hull would recognize that 1) autism has reached epidemic proportions (and there is no such thing as a genetic epidemic), 2) that just perhaps government agencies were “asleep at the switch” in policing the amounts of mercury being injected into children and 3) if thimerosal is not a contributing cause to the epidemic, then perhaps it might be wise to try and hypothesize what might be?

If anything “unresponsive” is too mild a description.

The greatest potential damage from Westover's arguments is that parents might forgo vaccination, increasing the risk of disease not only for their children, but also their friends and classmates. When immunization rates fall, these preventable diseases return with a vengeance — diseases like measles or rubella that can leave children mentally retarded, blind and deaf. Not vaccinating against childhood diseases carries a very real and demonstrable risk of serious illness, disability or even death.

Indeed, some parents might forgo vaccinating their children (not something I or any of the responsible proponents of the possible autism connection have advocated), but is that because of my columns raising valid concerns, or is it because of bureaucratic inaction that did not respond promptly and adequately to genuine concerns? Mr. Hull’s remarks put him squarely in the camp of “What you don’t know may hurt you, but if you don’t know, then you don’t have to worry about it.”

I do not think that is a healthy attitude for a public health official, and certainly not for his "public."

When it’s been over four years (how many vaccinated kids?) since the IOM found insufficient evidence to either accept or reject a causal relationship between thimerosal-containing vaccines and neurological disorders, but said the "hypothesis is biologically plausible," the onus for any doubts about the safety of vaccines lies not with those who question, but those who refuse to answer.

I urge readers to look at other, credible sources of information to reach their own conclusions. Links to several reliable sources can be found at

So do I. Readers might also check out and David Kirby’s site at as well. Do look at both sides of the issue and decide for yourself where the credibility lies. A hint -- it’s in the science, not in necessarily in initials like FDA, CDC, IOM or even MDH.