All posts on autism and thimerosal in vaccines

May 28, 2002. How do you defend yourself against the charge that you have caused an illness, despite the fact that the illness could have several origins, none of which might be sufficient to do harm by itself? This is the very difficult position that coal-burning power companies, pharmaceutical firms, dentists, producers of fungicides or fluorescent lights or thermostats all find themselves in because they use or transmit mercury or compounds of mercury.

Those who use mercury in their products are being blamed for many illnesses, including autism. Leading the fight is Lyn Redwood, whose son Will is autistic. She blames mercury emitted by Georgia Power company and thimerosal in vaccinations for her son's disorder. Even though there is no significant cluster of similar cases in her neighborhood, which might indicate an environmental cause, she blames them and others because her son is "especially sensitive" to mercury. Their attorney, who is representing six families, claims "In a fetus or in an infant, their saturation point is reached. They're born with a very, very high level of mercury relative to their ability to process it." This is an assumption. The mercury level of infants is not something that is usually measured. Of course, the only way a fetus can get mercury is through the mother. So, her vaccinations may be to blame for the assumed high levels of mercury in the fetus. However, maybe the mother ate contaminated fish or ate vegetables tainted with a mercury-based fungicide. Maybe. That seems to be the key word here. And perhaps and possibly.

It is fruitless to point out that many people who are not autistic were exposed to much higher levels of mercury as infants and children than those diagnosed with autism. Concern over those "especially sensitive to mercury" begs the question. "Special sensitivity to mercury" is an assumption. On the other hand, there is a very real concern that should be emphasized: balancing the benefits to society of vaccinations versus the known harm that will be done. For the millions who would have died of disease had there not been a vaccination program in effect, there are hundreds who will die because of the vaccine itself. The smallpox vaccine has eradicated smallpox worldwide and saves millions of lives a year.* "Over 80% of the world's children are now being immunized against the polio virus, and the annual number of cases has been cut from 400,000 in 1980 to 90,000 in the mid-1990s."* Over a million children a year die of measles in those countries where vaccinations are not available. Immunization may save more than 20,000,000 lives of children worldwide every year. Nevertheless, some children will die because of the vaccinations because they are "especially sensitive." It is hard to calculate exactly how many deaths each year are due to vaccines, but it is in the hundreds, not millions.* It is impossible to calculate the number of cases of autism that are due to vaccinations, or pollution, or dental amalgam, etc., since the current data do not support a causal connection between mercury and autism, much less between vaccinations and autism.

The Redwoods' argument is that even if no single source of mercury caused their son's autism, the accumulation of mercury from several sources did. So, all sources should share in the blame. Thus, there are two separate issues in the Redwoods' suit. One, does mercury cause autism? And two, if it does, should those who deliver mercury within the legal and scientific boundaries of safety be held accountable for a harmful effect due to accumulation from several "safe" sources?

the causal connection

Dr. Andrew Wakefield sounded the alarm a few years ago about a possible connection between the MMR vaccine and autism and bowel disease in children. Most scientists have dismissed Wakefield's work as inadequate and dangerous, but he is unrepentant and now claims that two new studies will prove him right. A measles epidemic in Ireland has been blamed on Wakefield. Fears of an epidemic in Scotland (where Wakefield operates) and England are also feared because of Wakefield's claims.

We now know that Wakefield was paid more than £400,000 by lawyers trying to prove that the vaccine was unsafe. The payments were part of £3.4m distributed from the legal aid fund to doctors and scientists who had been recruited to support a now failed lawsuit against vaccine manufacturers.*

Thimerosal has been used since the 1930s, but it has never been used in the MMR vaccine.* One would think that if thimerosal were so harmful, we might have detected it before now. It is used in vaccinations as a preservative to prevent contamination by microbes. "The amount of mercury a typical child under two years receives from vaccinations equates to 237.5 micrograms...."* For comparison, consider that a "6-ounce can of tuna fish contains an average of 17 micrograms of mercury."*  The daily mercury uptake from amalgam fillings is estimated to be about 3 micrograms.* (A microgram is one millionth of a gram. There are about 28 grams in an ounce.) "With the newly formulated vaccines, the maximum cumulative exposure during the first six months of life will now total to no more than 3 micrograms of mercury."* This small amount is most probably harmless in itself. However, Redwood claims that it is not harmless to those who are "especially sensitive." She and many others want the mercury out of all vaccines. No doubt, they will soon get their wish. But there can be no guarantee that whatever replaces thimerosal as a preservative may not eventually prove harmful to some who are "especially sensitive" to the substitute. That will be the problem of another group of parents, I suppose. If no preservative is used, any childhood bacterial infection may be blamed on the vaccination by some parents.

Is this just another sad case of people desperate to blame someone for their misfortune? Not quite. There are a number of scientists who support the Redwoods' claims. Some of these scientists look at the effects of mercury poisoning and compare them to the effects of autism. The parallels are striking. They also note that "Autism spectrum disorders have increased from 1 in 10,000 in 1978 to 1 in 300 in some US communities in 1999."*  And, while the rate of vaccination has not increased by 3000 percent, the number of vaccinations a child now receives during the first two years of life has increased. In any case, some scientists and many laypeople think that the increase in autism detection parallels the increase in vaccinations and that this correlation indicates a causal connection. (Correlations are notoriously slippery when it comes to establishing causal connections. The crime rate may have gone down at the same rate as the vaccination rate went up over the past twenty years, but no one would claim that one caused the other just because of a correlation.)

Nobody doubts the dangers of mercury poisoning. And it may be that one of the causal factors in autism is mercury. But proving that the mercury in thimerosal is not a crucial factor seems impossible, since even though studies indicate it is not a major source of mercury, one can always claim that anyone who had a vaccine and is autistic is "especially sensitive" to cumulative effects from various sources.

sources of mercury

What do we really know about how much mercury is harmful and how many delivery systems of mercury there are to be concerned about?

Mercury is a naturally occurring mineral that can be found throughout the environment. Mercury forms can be found as the elemental metal or in a wide variety of organic and inorganic compounds. There is a constant biogeochemical cycle of mercury. This cycle includes: release of elemental mercury as a gas from the rocks and waters (degassing); long-range transport of the gases in the atmosphere; wet and dry deposition upon land and surface water; absorption onto sediment particles; bioaccumulation in terrestrial and aquatic food chains.*

Mercury....occurs naturally and is found in very small amounts in oceans, rocks and soils. It becomes airborne when rocks erode, volcanoes erupt and soil decomposes. It then circulates in the atmosphere and is redistributed throughout the environment. Large amounts of mercury also become airborne when coal, oil or natural gas are burned as fuel^[*] or mercury-containing garbage is incinerated. Once in the air, mercury can fall to the ground with rain and snow, landing on soils or water bodies, causing contamination.*

Elemental and inorganic mercury salts can be transformed into organic mercury by the bacteria in the bottom mud in water bodies. Unlike elemental mercury, organic mercury (often referred to as "methylmercury") can be readily absorbed in humans. The most likely source of methylmercury is eating contaminated fish.^[*] Human exposure to methylmercury can result in long-lasting health effects, especially on fetal development during pregnancy. In addition, mercury poisoning has been linked to nervous system, kidney and liver damage and impaired childhood development. Nervous system disorders include impaired vision, speech, hearing and coordination.*

The Redwoods claim that the mercury from vaccines and power plants don't affect most people, but cause autism in the "especially sensitive" by adding to other sources of mercury beyond some "critical point" of safety. They may be right, and the claim seems impossible to disprove. It will be interesting to see what juries think--if it ever gets that far--since courtroom standards of scientific evidence are notoriously low. [update (11/19/2007): juries won't be likely to decide the more than 4,900 cases pending in 2007. An Autism Omnibus Court of Federal Claims has been set up.] It will also be interesting to see what those sued will do. Will they give up and pay off the suers? Will they decide that it will probably be cheaper to settle than to go to court and win? Or will they try to fight it out, knowing how the media and the public love an Erin Brockovich-type story?

mercury and autism

The Redwoods' concern about mercury being tied to autism began when they read a report in 1999 from the Food and Drug Administration (FDA) that said babies who receive multiple doses of vaccines with thimerosal "may be exposed to more mercury than recommended by federal guidelines."*  The Environmental Protection Agency (EPA) says "five parts per million is diagnostic for mercury toxicity."* But, they recommend taking action if the mercury level reaches one part per million. When he was four or five, the Redwoods' son had "mercury levels in his hair" of "4.8 parts per million," according to his mother. However, "the amount of mercury in hair does not reflect the concentration in the rest of the body."* According to Dr. Robert Baratz, "analyzing hair for mercury is a waste of time and money and cannot be used to diagnose mercury poisoning. A competent practitioner would easily know this."* According to Dr. Stephen Barrett, hair analysis is a common sign of quackery.

Mrs. Redwood says she had two injections while pregnant and one while breastfeeding that contained thimerosal.

However, the EPA's reference dose, or RfD, was truly cautious, based on a single episode of methylmercury poisoning in Iraq in which 81 children were exposed to high levels of mercury in utero. The EPA calculated the RfD by determining the dose that produced a 10% prevalence of adverse neurological effects in the affected children, including late walking, late talking, and abnormal neurological scores. The agency then placed a 95% confidence interval around this dose and divided the lower bound of the interval by an "uncertainty factor" of 10 to arrive at the RfD.*

Thimerosal is metabolized in humans to ethylmercury, not methymercury, but guidelines for safe mercury intake relate only to methylmercury. The FDA's Center for Biologics Evaluation & Research, the source of the Redwoods' information about the potential dangers of vaccinations, assumed that "the toxicity of the ethyl compound was equivalent to the methyl compound."* Why? There is very little known about the toxic effects of ethylmercury. Having insufficient knowledge regarding the dangers of ethylmercury, the FDA treated it as if it were methylmercury. This may seem like erring on the side of caution, but it isn't. For all the FDA knew, the ethyl compounds could be significantly more dangerous than the methyl compounds. Then again, the ethyl compounds might not be very dangerous at all.

Further complicating matters is the fact that, even if mercury is a causal agent in autism, genetic and other biological functions might be involved. Infections might weaken detoxification capabilities (like the production of glutathione) in some infants or young children.* This complicates matters as far as identifying what may be a significant causal factor in an individual's autism, but it simplifies matters for those who claim their children are "especially sensitive." Their child may be born with a genetic predisposition to autism, or a weakened immune system, or a defective ability to detoxify. Ethylmercury may have triggered autism. On the other hand, their child may have been born with no such predisposition or weaknesses. But, an infection may have weakened the immune system or the ability to detoxify. Or, it could have been methylmercury that triggered the autism and the source could have been a mother's fondness for tuna fish. Perhaps. Possibly. Maybe.

update: November 22, 2003. The New England Journal of Medicine has recently published a retrospective study done in Denmark that involved over 500,000 children. The study provides "strong evidence against the hypothesis that MMR vaccination causes autism."
[thanks to Harrison Bolter]

further reading

• A controlled study of mercury levels in hair samples of children with autism as compared to their typically developing siblings

• Surprise, surprise! Andrew Wakefield was paid by lawyers to undermine the MMR vaccine Jan. 1, 2007

• Why can't doctors be more scientific? Hugh Pennington, London Review of Books, July 8, 2004

• A Population-Based Study of Measles, Mumps, and Rubella Vaccination and Autism New England Journal of Medicine Volume 347:1477-1482 November 7, 2002 Number 19

• The Not-So-Crackpot Autism Theory

• Government: Mercury in dental fillings still safe - CNN - Nov. 15, 2002

• National Network for Immunization Information

• Evaluating Immunization Info on the Web

• Vaccines and Mercury from HealingArts

• Infant Immune System Stronger than Many Parents Think

• Addressing Parents’ Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant’s Immune System?

• Abstract: "Concentrations of blood, serum and urine components in relation to number of amalgam tooth fillings in Swedish women." Ahlqwist M, Bengtsson C, Lapidus L, Lindstedt G & Lissner L.  Comm Dent Oral Epidem 23(4):217-221 (1995) (In a study of 1,462 women, amalgam fillings were not found to be associated with impairment of kidney function or immunological status.)

• shots in the dark New Yorker, October 11, 1999

• Amalgam-related illness FAQ

• Autism: A Unique Type of Mercury Poisoning

• Why Is Mercury Important?

• Mercury in vaccines leads to wave of suits

• The Dark Side of Erin Brockovich By Michael Fumento

• Why Autism Is More Common in Males: Testosterone Affects Gene

September 3, 2003.  A new study published in Pediatrics magazine claims that there is strong evidence from a study in Denmark that thimerosal, the mercury-containing preservative that used to be commonly used in vaccines, is an unlikely contributor to the development of autism.

Danish researchers examined data on 956 children diagnosed with autism from 1971 to 2000. They said the autism incidence rate climbed steadily from less than one child per 10,000 in 1990 to nearly 5 per 10,000 in 1999, seven years after thimerosal was removed from vaccines in Denmark.*

"Thimerosal has been eliminated from childhood vaccines in most industrialized countries," said lead author Dr. Kreesten Meldgaard Madsen. "If indeed thimerosal was an important cause of autism, (autism rates) should soon begin to decline in these countries."

Dr. Robert Byrd of the University of California, Davis, who has studied a surge in autism cases in California, said the Danish study won't settle the question because it used only data on hospitalized autistic children until 1995 and then added outpatients after that. According to Dr. Byrd, this change in data collection confuses the issue of whether there were any changes in the autism rate itself. Even so, Bryd is well aware that autism rates continue to rise around the world while the use of mercury-based vaccines decreases.

Mark Blaxill of Safe Minds (Sensible Action for Ending Mercury-induced Neurological Disorders) goes much further than Bryd and accuses the authors of the study of manipulating "the incidence of autism in an attempt to clear thimerosal-containing vaccines of any role in the etiology of the disease."* Why would these scientists intentionally manipulate data to exonerate thimerosal? Because, says Blaxill, pediatricians, the ones who read Pediatrics, administer vaccines and he thinks they want to stop the movement to eliminate thimerosal from vaccines. Many pediatricians are no longer administering thimerosal-based vaccines because such vaccines are being phased out on the off-chance that the mercury in such vaccines is harmful. However, Blaxill believes that it is damning that two of the authors of the study work for the Danish manufacturer of thimerosal vaccines and Pediatrics didn't mention this. Nor did they mention that it gets advertising revenue from manufacturers of vaccines. Personally, I think it most appropriate that someone who works for a manufacturer of a product that has been claimed to be harmful would be involved in a study on the effects of that drug. I could understand Blaxill's complaint if  the researchers had found that as thimerosal decreased so did autism but they refused to publish the study. Also, the fact that manufacturers of vaccines advertise in Pediatrics seems to be a pretty lame reason for only publishing articles that support the claim that vaccines are detrimental, which is what Blaxill seems to be suggesting. As to the point about disclosure, I think Blaxill is right and I contacted his organization for the names of the two doctors and the company they work for. Melissa Sneath of Safe Minds informed me that the two doctors are Anne-Marie Plesner, M.D., Ph.D. and Peter H. Andersen, M.D. They work for Statens Serum Institute. I contacted Statens Serum Institute and Dr. Peter Andersen, of the Department of Epidemiology, responded. He claims that Statens hasn't used thimerosal in their vaccines for children for over ten years.

Since 1992 our own vaccine production has been free of thimerosal, i.e. since 1992 no Danish child has received a thimerosal-containing vaccine recommended within the childhood vaccination program. The vaccine used against hepatitis B contained thimerosal until 2000, but this vaccine is not a part of the recommended schedule and has been given to very few children at risk.

Dr. Andersen also informed me that Dr. Plesner was a consultant in the Dept. of Medical Affairs at Statens at the time of preparing the paper. She has since left the Institute and now has a position in the County Medical Office within the municipality of Copenhagen.

Dr. Andersen also sent me a copy of a paper recently published in the American Journal of Preventive Medicine (2003; vol. 25, no. 2, pp. 101-106) that concluded:

The body of existing data, including the ecologic data presented herein, is not consistent with the hypothesis that increased exposure to Thimerosal-containing vaccines is responsible for the apparent increase in the rates of autism in young children being observed worldwide ("Autism and Thimerosal-Containing Vaccines Lack of Consistent Evidence for an Association" by Paul Stehr-Green, DrPH, MPH, Peet Tull, Michael Stellfeld, MD, Preben-Bo Mortenson, DrMedSC, Diane Simpson, MD, PhD).

According to the authors of the study, they compared "the prevalence/incidence of autism in California, Sweden, and Denmark with average exposures to Thimerosal-containing vaccines" for the period covering the mid-1980s through the late-1990s. (If you would like a copy of this article, write to me at rtcATskepdic.com, replace the AT with the @ sign.)

It would be impossible to calculate how many lives have been saved by the products of Statens Institute and similar laboratories that manufacture vaccines. It is also impossible to discover who might be "especially sensitive" to thimerosal. However, the number of lives lost to diseases like measles because of parental fear of vaccinating children is calculable. For example, there were over 1,500 reported cases of measles in an epidemic in Ireland in 2000. Because of not being vaccinated, three children died.*

further reading

• Immunizations: Life saving or harmful to children? Parents, health care providers weigh benefits and risks of vaccines By Jennifer Weaver
   

May 19, 2004. An examination of scientific studies worldwide has found no convincing evidence that vaccines that contain thimerosal cause autism.

Mark Blaxill, the father of an 8-year-old girl with autism, is the current leader of the Coalition for Safe Minds, a group that sponsors research specifically designed to find a connection between vaccines and neurological disorders. He says that the new report from a committee of experts appointed by the Institute of Medicine is "premature."

Even though the evidence for a link between thimerosal and neurological disorders such as autism is lacking, manufacturers of vaccines stopped using mercury-based preservatives in 2002. So far there has been no noticeable significant drop in the rates of autism.

Today's New York Times article by Sandra Blakeslee provides a bit of the history of this issue.

September 9, 2004. Dr. Michael Fitzpatrick, author of MMR and Autism (Routledge 2003), has a very interesting article in the Guardian regarding parents of autistic children who believe their personal experience and research--most of which has been guided only by the desire to prove what they already believe, namely, that their children's autism was caused by vaccinations--qualify them as experts on both autism and vaccination. As the parent of an autistic child, Fitzpatrick sympathizes with the desire to find something to blame for the autism. But, as Dr. Fitzpatrick notes, being a parent of an autistic child does not give him "any special insights into the question of what causes autism, or into any other aspect of the condition."

There are several anti-immunization websites and some of them are posting inaccurate information about the evidence of a causal connection between vaccinations and autism. Fitzpatrick's concern, however, is not just with the misinformation but that

Any parent who looks to the anti-immunisation campaigns for information will readily find strident condemnations of the government, the medical establishment and the drug companies. Anybody who defends immunisation can expect abuse and allegations of corruption or conspiracy. The basic thrust of much of it is that the pro-vaccination party has commercial links with drug companies. Yet, perhaps not surprisingly, these anti-vaccination groups often have their own links with commercial interests.

He notes that a group that goes by the swell name of Jabs (Justice, awareness and basic support) has been in litigation against MMR for more than a decade. The legal firm of Alexander Harris

cleared around £5m out of the total of £15m of legal-aid funding spent before the Legal Services Commission pulled the plug last October. Jabs' encouragement of parents to join this ill-conceived quest for compensation has had a demoralising effect, not only on the families involved, but on the parents of children with autism, who have been made to feel guilty that by giving their children MMR they may have caused their condition.

According to Fitzpatrick, the anti-immunization websites provide links to private clinics offering alternative vaccines to MMR and to "mercury-free" MMR vaccines. "These clinics have been major beneficiaries of popular anxieties about immunisation, making 'substantial' profits by providing inferior vaccines at inflated prices, to parents whose fears have been inflamed by misinformation and scare-mongering journalism." One such beneficiary was Dr. David Pugh, whose clinics in Sheffield and Elstree, Hertfordshire, were closed down after allegations of unsanitary and fraudulent practices. Pugh, who faces trial on criminal charges, has been endorsed by a number of parent groups.

update: March 15, 2006

A Review of “Early Downward Trends in Neurodevelopmental Disorders Following Removal of Thimerosal-Containing Vaccines” by Interverbal
 

April 19, 2006. A study published in the Journal of the American Medical Association found no significant difference in adverse neuropsychological or renal effects between children with mercury dental fillings and those with non-mercury fillings. Even so, because of fear that mercury fillings might be dangerous, there are some 70 million dental amalgam restorations done annually in the United States. That's a lot of unnecessary dental work.

March 21, 2006. The headline over the story in this morning's Sacramento Bee reads: Thimerosal linked to immune system ills. There should have been two more words in the headline: "in mice."

The subhead may have mitigated some of the aha! I told you so! reaction from the thimerosal-causes-autism crowd: The vaccine component has been suspected in autism, but study is no 'smoking gun' to UCD expert.

Still, it is likely that this study at UC Davis, which found that thimerosal disrupts the normal biological signals occurring in dendritic cells in mice,  will be seen by some as vindicating the belief that thimerosal in vaccines caused their children's autism. (Dendritic cells are responsible for triggering the body's immune response to bacteria, viruses, or other antigens.) Adding fuel to this belief is the fact that many autistic children suffer from immunological disorders "including gut disorders, allergies and frequent infections."*

"This is not a smoking gun," said Isaac Pessah, the University of California, Davis, toxicologist who led the study. "We now understand one of the ways in which thimerosal could adversely impact the immune system," Pessah said.

Future studies must be done to discover "whether dendritic cells from children with autism are particularly sensitive to the effects of thimerosal, various forms of mercury, and other environmental toxicants."*

Previous studies have not found a correlation between vaccines with thimerosal and autism.

Update: July 18, 2006

Another study has found that "There is no relationship between the level of exposure to MMR vaccines and thimerosal-containing vaccines and rates of autism."* The Canadian study was published in the journal Pediatrics.

See also:

• Autism Watch

• Frequently asked questions about thimerosal: provided by the National Institute of Allergy and Infectious Diseases

Kennedy's rant

July 9, 2005. Sounding like a demagogue intent on spreading fear and loathing among voters, Robert F. Kennedy Jr. has spun a yarn about a grand government/pharmaceutical conspiracy. The co-conspirators met in private in the year 2000 at "the isolated Simpsonwood conference center in Norcross, Georgia," and were motivated by greed and indifference to the suffering of little children. Yet, they masquerade as benefactors bearing the gift of lifesaving vaccines. According to Kennedy, public health officials have conspired with drug makers to "poison a generation of American children." He makes this and other unfounded claims in an article published in Rolling Stone magazine and online at Salon.com.

Kennedy claims that "top government scientists and health officials" and drug industry representative met five years ago "to discuss a disturbing new study that raised alarming questions about the safety of a host of common childhood vaccines administered to infants and young children." And what study is he referring to? He claims there was an analysis of the medical records of 100,000  children done by Tom Verstraeten (TV), a Center for Disease Control epidemiologist. According to Kennedy, TV found that thimerosal, a mercury-based preservative that was removed from childhood vaccines beginning in 1995 because of political pressure fueled by fear rather than science, "appeared to be responsible for a dramatic increase in autism and a host of other neurological disorders among children." This would be quite a scoop, if true, because several studies have been published that strongly support the position that there is no causal link between childhood vaccines and autism or other diseases. Unfortunately for Kennedy, the co-conspirators have published a 286-page account of their "private" meeting.

According to Kennedy, TV told the co-conspirators that he "was stunned by what he saw, citing the staggering number of earlier studies that indicate a link between thimerosal and speech delays, attention-deficit disorder, hyperactivity and autism." Actually, TV says that he went back through the literature  and "was actually stunned by what I saw because I thought it is plausible." "It" refers to the biological mechanism of mercury causing autism. TV goes on to say, after a brief review of the literature, that "basically to me that leaves all the options open, and that means I cannot exclude such a possible effect." Kennedy would have us believe that TV thinks the evidence supports this alleged link. TV says no such thing.

According to Kennedy,

Dr. John Clements, vaccines advisor at the World Health Organization, declared that "perhaps this study should not have been done at all." He added that "the research results have to be handled," warning that the study "will be taken by others and will be used in other ways beyond the control of this group."

According to the published report of the co-conspirators, what Dr. Clements actually says makes him appear to be clairvoyant, for he seems to have predicted what characters like Kennedy would do with anything the group had to say about the issue. Here is what Clements said:

My message would be that any other study, and I like the study that has just been described here very much. I think it makes a lot of sense, but it has to be thought through. What are the potential outcomes and how will you handle it? How will it be presented to a public and a media that is hungry for selecting the information they want to use for whatever means they have in store for them?

Dr. Robert Brent, a pediatrician at the Alfred I. duPont Hospital for Children in Delaware, followed up Dr. Clements's comments with more of the same and suggested not a cover-up but that more research be done:

...no matter what you come up with somebody on one side will accuse you of doing something to get a negative result. Then if you come up with a positive result using the same data, the person on the other side will say see, we were right, it is causal. So I really encourage the investigators to get other populations to study because of the fact that I do not think reanalysis of this data is going to be as helpful as we would hope.

Kennedy writes:

But instead of taking immediate steps to alert the public and rid the vaccine supply of thimerosal, the officials and executives at Simpsonwood spent most of the next two days discussing how to cover up the damaging data.

The fact is that this meeting occurred in 2000. By 1995, thimerosal in vaccines was beginning to be phased out worldwide. By 1999 it was being phased out in the United States. "Today, with the exception of some flu vaccines, none of the vaccines used in the U.S. to protect preschool aged children against 12 infectious diseases contain thimerosal as a preservative."* Some pediatric vaccines have never had thimerosal in them (e.g., the MMR vaccine).

Several studies have been published that demonstrate Kennedy doesn't know what he's talking about.

Kennedy seems to have been sucked into this maelstrom by fanatical advocates such as Mark Blaxill, whose daughter is autistic, of Safe Minds. Kennedy tells us:

I devoted time to study this issue because I believe that this is a moral crisis that must be addressed. If, as the evidence suggests, our public-health authorities knowingly allowed the pharmaceutical industry to poison an entire generation of American children, their actions arguably constitute one of the biggest scandals in the annals of American medicine. "The CDC is guilty of incompetence and gross negligence," says Mark Blaxill, vice president of Safe Minds, a nonprofit organization concerned about the role of mercury in medicines. "The damage caused by vaccine exposure is massive. It's bigger than asbestos, bigger than tobacco, bigger than anything you've ever seen."

This horse should be dead by now but as long as there is some political benefit to scaring people into thinking Big Government is conspiring with the Big Drug Cartel this horse will continue to be dragged back on stage for an encore performance by knights in tarnished armor claiming to be defending our children against outrageous abuses.

Is there any truth in Kennedy's article? There may well be but I am not going to waste my time tracking down every claim he makes since I already know that he has distorted some very important data and twisted facts to serve his purpose. There is no way to close this issue of mercury and autism. Whatever data is available can always be mined for some gem that supports the conspiratorial theory and there is always hope that some future study will provide some support for the causal belief. No study will ever be able to show with absolute certainty once and for all that thimerosal or any other substance does not cause autism in some people some of the time.

In the meantime, we must ask ourselves what is the likelihood that the Centers for Disease Control and Prevention (CDCP), the Food and Drug Administration (FDA), the World Health Organization (WHO), the Institute of Medicine (IOM), and the American Academy of Pediatrics have joined a drug cartel to dupe the public by agreeing that there is no evidence linking thimerosal and autism? Are we to believe, for example, that the WHO made it all up when they published the results of a study that examined the health records of 109,863 children born in Britain from 1988 to 1997 and found that children who had received the most thimerosal in vaccines had the lowest incidence of developmental problems like autism?* Or are we to believe the parents of autistic children who are desperately seeking a villain?

It seems that Kennedy has been used by leaders of the anti-vaccine lobby to promote their cause, while at the same time fueling an unnecessary distrust of vaccination. His article will not save any lives but it could well cost a few. He put his credibility on the line by beating on this dead horse. It will probably cost him plenty.

I can't begin to calculate the irony in Kennedy's concluding statement:

It's hard to calculate the damage to our country -- and to the international efforts to eradicate epidemic diseases -- if Third World nations come to believe that America's most heralded foreign-aid initiative is poisoning their children. It's not difficult to predict how this scenario will be interpreted by America's enemies abroad. The scientists and researchers -- many of them sincere, even idealistic -- who are participating in efforts to hide the science on thimerosal claim that they are trying to advance the lofty goal of protecting children in developing nations from disease pandemics. They are badly misguided. Their failure to come clean on thimerosal will come back horribly to haunt our country and the world's poorest populations.

Yes, it is hard to calculate the damage to our country and to millions of children around the world should their parents or governments come to believe that vaccines are intended to harm them thanks to the demagoguery and fearmongering of sincere, even idealistic but misguided environmental lawyers.

further reading

• Sticking Up for Thimerosal Read the studies—it's safe by Arthur Allen (Slate, April 2005)

• ABC's critique of Kennedy's article (video)

• Mistrust rises with autism rate by Anita Manning, USA Today, July 6, 2005

• On Autism's Cause, It's Parents vs. Research by Gardner Harris and Anahad O'Connor, New York Times, June 25, 2005

• Top 10 Myths and Truths about MMR

• If you think it's just about mercury when it comes to vaccines, you're wrong

• Panel Finds No Evidence to Tie Autism to Vaccines by Sandra Blakeslee, NY Times, May 19, 2004

• Robert F. Kennedy Junior’s completely dishonest thimerosal article

• Lies, damn lies, and quote mining

• Salon.com flushes its credibility down the toilet

• Robert F. Kennedy adds more evidence that people with critical thinking skills are an endangered species

• Mercury, Autism, and Imus

• The Man Behind The Vaccine Mystery, CBS, Dec. 12, 2002

July 13, 2005. In my July 9 post I asked whether there might be some truth in Robert F. Kennedy Jr.'s article claiming a massive conspiracy between the government and drug companies to "poison a generation of American children." I admitted that there might be but said that I was not going to waste my time tracking down every claim he makes since I already know that he has distorted some very important data and twisted facts to serve his purpose. I'm not going to try to respond to every claim he makes, but one in particular ought to be addressed: the claim that protecting drug companies in the Homeland Security Act from lawsuits claiming thimerosal causes autism is the smoking gun for the conspiracy hypothesis. Here is what Kennedy writes:

The drug companies are also getting help from powerful lawmakers in Washington. Senate Majority Leader Bill Frist, who has received $873,000 in contributions from the pharmaceutical industry, has been working to immunize vaccine makers from liability in 4,200 lawsuits that have been filed by the parents of injured children. On five separate occasions, Frist has tried to seal all of the government's vaccine-related documents -- including the Simpsonwood transcripts -- and shield Eli Lilly, the developer of thimerosal, from subpoenas. In 2002, the day after Frist quietly slipped a rider known as the "Eli Lilly Protection Act" into a homeland security bill, the company contributed $10,000 to his campaign and bought 5,000 copies of his book on bioterrorism. The measure was repealed by Congress in 2003 -- but earlier this year, Frist slipped another provision into an anti-terrorism bill that would deny compensation to children suffering from vaccine-related brain disorders. "The lawsuits are of such magnitude that they could put vaccine producers out of business and limit our capacity to deal with a biological attack by terrorists," says Andy Olsen, a legislative assistant to Frist.*

I want to make it clear that I do not know what Bill Frist's motives were, but I am willing to assume they were selfish and greedy and part of payback for contributions to Republicans. Others may also be involved and they, too, may have ulterior motives. For example, a CBS story reports that House Majority Leader Dick Armey claimed that he was the one who put the Lilly protection clause in the 2002 Homeland Security act. "I did it and I'm proud of it," he said. Why? He claimed that he did it to keep vaccine-makers from going out of business under the weight of mounting lawsuits. "It's a matter of national security," he said at the time. "We need their vaccines if the country is attacked with germ weapons." Furthermore, Armey claimed that he was asked to put in the protection clause by the White House.

Regardless of the real motivations of Frist or Armey or anyone else for that matter, the argument that Lilly and other drug companies should be given protection from thimerosal lawsuits as a matter of national security must be considered on its own merits. People with good motives can make bad arguments and people with evil motives can make good arguments. The important question here is whether the national security argument is cogent or not.

Of course, as soon as I present my case that the argument is cogent, I know my motives will be questioned. So be it. However, if you know nothing else about logic you should at least know that attacking a person's motives rather than the person's argument is fallacious. For those who don't already know, it's called the ad hominem fallacy.

The national security issue is not bogus. There is a real threat from bio-terror and bio-error (remember the deadly flu virus sent to labs around the world by mistake?). We do not have socialized medicine. All drugs and vaccines are produced by private enterprises. The same is true for most weapons. I would like to live in a country where no weapons of mass destruction are allowed to be produced. But I can't deny that the government has an obligation to protect its citizens and therefore has an obligation to protect those industries that are essential to protecting its citizens. On the other hand, the duty to protect these vital industries has limits. A protected industry should not be allowed to run roughshod over citizens' rights or cause intentional harm to citizens without being held accountable. For example, no arms industry company should go unpunished if it were to test its weapons on innocent civilians. No drug company should go unpunished if it were to infect innocent people with smallpox in order to test its vaccines.

But some protection of vital industries is warranted. People should be allowed to sue weapons manufacturers in some circumstances but not every time somebody is killed accidentally or intentionally with a gun, otherwise the industry would go bankrupt and be unable to supply the military with needed weaponry. If lawsuits without much merit became a threat to a vital industry, the government would have a duty to prohibit those lawsuits.

There are two questions that need to be answered regarding government protection of drug companies from lawsuits claiming thimerosal caused autism. First, are these lawsuits probably without merit? Second, do these lawsuits threaten to bankrupt a vital industry?

If you read my post of July 9, you know that I believe a strong case has been made that the answer to the first question is a resounding YES. Thus, I would say that there is nothing intrinsically wrong with lawmakers protecting drug companies from such lawsuits. However, this protection comes in the Homeland Security Act. Thus, the second question, even though more difficult to provide a slam-dunk argument for, must be answered.

One question we must ask is how much money are we talking about in these lawsuits? Is it enough to threaten to shut down or intimidate drug companies to the point that they could not provide needed drugs and vaccines in the case of bio-terror or bio-error? Another thing we might consider is whether any big company has ever been closed down by fear rather than scientific evidence through lawsuits. The second question is easy to answer. It happened to Dow Corning with silicone breast implants.

On January 9, 1997, I wrote

The two experts who testified for the lawyers who sued Dow Corning over breast implants were seemingly reputable scientists. They testified to the causal connection between breast implants and such things as connective tissue disease. Dow paid off millions and filed for bankruptcy. Jenny Jones and Oprah had programs featuring women who'd had breast implants and were suffering from painful disorders. The general public would reasonably conclude from such behavior that there must be strong evidence that breast implants caused these disorders. Yet, the rest of the medical scientific community maintains that given the more than one million women who have had breast implants, it would be expected by chance, if there were no causal connection between the implants and disease, that about 1% or 10,000 women would be ill, because that is the percent of women in the general population who suffer from these problems. That is what the studies have found. If there were a causal connection, the percentage of women who'd had breast implants suffering from diseases such as connective tissue disease should be significantly higher than that for women who do not have breast implants. It isn't.

It is hard not to be moved by anyone's suffering, but lawyers, scientists and jurors have a responsibility to get at the truth. Unfortunately, all too often interest in the whole truth, necessary to achieve justice, is suppressed in favor of finding a perpetrator, guilty or not, who can be blamed for causing such pain and suffering.

Here is what I wrote on October 28, 2003:

Boston Globe Columnist Alex Beam has an interesting article today in praise of Marcia Angel, former executive editor of the New England Journal of Medicine. Angel brought the wrath of feminist hell upon herself in 1992 when she wrote an editorial challenging the Food and Drug Administration's decision to ban the manufacture of silicone breast implants. She dared to challenge the FDA, even though nobody had done any medical studies on the issue. It didn't matter. The lawyers extorted a $4.25 billion settlement against the implant manufacturers without needing any scientific evidence that the implants were harming women. Angel got a book out it: Science on Trial: The Clash of Medical Evidence and the Law in the Breast Implant Case. Recently, an FDA advisory panel voted to lift the ban on silicone implants.

"The whole sequence was upside-down," Angel says. "First we had the lawsuits, then the FDA ban, and then the announcement of the largest class-action settlement in history. Only two months later did we get the first scientific study of the issue in question. What causes this is the use of expert witnesses. The expert gives an opinion, and that becomes the evidence. Since they are hired by the adversaries, they get the most extreme people they can find. In science it's the opposite. It doesn't matter who you are; what matters are what your data say."

The data didn't support the lawyers or the feminists.

But it didn't matter. And it is likely that it won't matter if lawyers go on the attack in pursuit of settlements for alleged damage done by vaccines.

Kennedy quotes Dr. Robert Brent as saying: "We are in a bad position from the standpoint of defending any lawsuits." What Kennedy doesn't mention is that Brent was not concerned about the merit of the lawsuits, but the cost given past "major tragedies with statistical associations."* Brent noted that it took 19 years and millions of dollars spent in several thousand lawsuits before the FDA removed an unnecessary warning about congenital heart disease and progestational agents. I don't know how many lawsuits have been filed against the makers of vaccines with thimerosal. One report I read claimed there are over 150. Kennedy writes of 4,200 lawsuits. There is also a class action lawsuit. Do these suits constitute a large enough threat to justify the fear that if allowed to go forward they could severely weaken or  destroy by bankruptcy the Lilly company, a company that produces vaccines that may be needed in large quantities in case of a major bio-error or a bio-terrorist attack? There's no way to know for sure, but the consequences could be so disastrous that erring on the side of national security seems clearly justified, even if it wasn't the real motive for the Lilly protection. What's happened in the past doesn't necessarily have to happen again in the future. But it could. Is the threat of bio-error or bio-terror real enough to warrant such concern. You bet it is. If you doubt it, take a few minutes to read Our Final Hour -  A Scientist's Warning: How Terror, Error, and Enviornmental Disaster Threaten Humankind's Future in this Century--On Earth and Beyond by Martin Rees.
 

Oprah and the mother warriors against science

"Being a parent of an autistic child does not give one "any special insights into the question of what causes autism, or into any other aspect of the condition." --Dr. Michael Fitzpatrick, parent of an autistic child

September 26, 2007. Ignorance combined with benevolent intentions by celebrities with access to mass media outlets can cause untold harm to countless numbers of people. For all the good that Oprah Winfrey has done with her money and influence, she has done an awful lot of harm by treating celebrities as if they were scientists and treating victims as if they were experts. Giving authority to uninformed celebrities posing as victims and passing off their magical thinking as truth may be Oprah's worst sin. Oprah's viewers trust her and that trust translates into faith in what her guests say, especially when Oprah validates them as she did Jenny McCarthy (Playboy Miss October 1993 and MTV star) and Holly Robinson Peete (actress and wife of former NFL player Rodney Peete). For their defiance of medical science and for their faith in "the mommy instinct" regarding autism, Oprah called these celebs "mother warriors." She might just as well have called them mother killers. McCarthy's "mommy instinct" tells her that the MMR vaccine caused her son's autism. And even though she didn't advise mothers to not vaccinate their children, some viewers will undoubtedly take away that message, especially if they follow their "mommy instinct" instead of sound medical advice.

On July 18, 2006, I noted that children are dying of measles again because mothers were not having their children vaccinated for fear of causing autism in their children. Children who aren't being vaccinated endanger other children they come in contact with, especially those with weakened immune systems. Throughout Europe, many parents stopped bringing in their children for the MMR vaccination. Cases of measles in England are at a 20-year high following the collapse in MMR immunization rates.* The panic is due to at least two things: Andrew Wakefield and widespread belief that governments are conspiring with pharmaceutical firms to hide the truth about vaccines. I wrote about Wakefield in 2002. You can read about Dr. Wakefield and other mothers with strong "mommy instincts" about autism and vaccines here.

Despite the fact that there is no compelling scientific evidence that the MMR vaccine or the ethylmercury (not methylmercury) that used to be used as a preservative in the vaccine has caused any case of autism anywhere in the world, many people still buy into the myth that, as McCarthy put it, the MMR vaccination is "the autism shot." The evidence is very strong that there is no causal connection at all between the MMR vaccine and autism. When your "mommy instinct" conflicts with overwhelming scientific evidence contrary to your instinct, if you are a rational person you will begin to mistrust your mommy instinct and admit that you are probably wrong. However, we all know that emotionally based beliefs are hard nuts to crack and convincing a person that evaluating one's own experience is sometimes a treacherous enterprise will often fall on deaf ears.

I didn't see the Oprah show with McCarthy and Peete, but I read the transcript of the show called "Mothers Battle Autism." I heard about the Oprah program from Dr. Steven Novella while listening to the Skeptic's Guide to the Universe podcast #113. Dr. Novella mentioned that some of the harm that will be done to children because their mothers won't have them vaccinated will show up later in life when the children grow up to be blind. In 1941, an Australian ophthalmologist found that many children are born with congenital cataracts and that blindness followed an outbreak of rubella. This was the first evidence that rubella could permanently damage the developing fetus.* We now know that not only blindness but deafness, heart defects, and retardation can result in children born to mothers infected with rubella.*

So, thank you Oprah, for hosting and supporting these "mother warriors." Thanks to you we'll have fewer mouths to feed in the future and some of those who survive won't be able to see what a mess we've made of things or hear people complain about it. And thank you for encouraging your millions of viewers to have more faith in the opinions of a former Playmate of the month and an actress than in the evidence produced by years of research by highly educated scientists. Thank you for encouraging mistrust of pediatricians and for reminding us that parents know better since they're, well, parents! Your "ask the experts" (Jenny and Holly) is a gift to us all. Finally, thank you for not subjecting us to the opinions of scientists and the opinions of parents like Dr. Michael Fitzpatrick. Mommy intuitions trump science any day. Still, I would have been more impressed had Jenny and Holly worn white lab coats and held clipboards. Anyway, I look forward to your program on magical thinking where you expose the fatal flaws in scientific methods and awaken the world to the superiority of personal experience, instinct, and intuition.

follow-up

The day after the above was posted, Los Angeles Times reporter Denise Gellene published an article on a seven-year study of 1,047 children who received mercury-containing vaccines as infants. This study, funded by the Center for Disease Control and Prevention, focused on looking for effects such as learning difficulties and developmental delays, and did not assess autism-spectrum disorders. The researchers studied forty-two neuropsychological outcomes. The authors of the study write:

Our study does not support a causal association between early exposure to mercury from thimerosal-containing vaccines and immune globulins and deficits in neuropsychological functioning at the age of 7 to 10 years.

The study was published today (September 27, 2007) in The New England Journal of Medicine.

In a classic example of pseudosymmetry, Gellene writes: "some scientists and advocacy groups have argued" that mercury causes autism, "the issue is contentious," and "several thousand parents are seeking legal compensation on behalf of children who developed autism after receiving vaccinations." (The human body metabolizes thimerosal, used as a preservative in the MMR vaccine until several years ago, as ethylmercury.) Gellene doesn't mention, of course, that these scientists (like Andrew Wakefield) and advocacy groups (whose beliefs are based mostly on the mommy instinct) have no credibility within the larger scientific community, which does not consider the issue contentious at all. The larger scientific community considers the issue an annoyance that hinders doing research in other areas that might lead to some fruitful discoveries that could improve treatments for autism. As evidence of the harm these contrarians are causing, the CDC, which spent $5.3 million on this study, is sponsoring two large epidemiological studies exploring the possible link between thimerosal and autism, despite the fact that there have already been several large studies that have found no link between the two. This money is being wasted. For one thing, because of all the fear generated by Wakefield and the parents' advocacy groups that have taken their case directly to the media and to the courtroom, MMR vaccines no longer have mercury in them. For another thing, the evidence is already overwhelmingly supportive of the position that there is no causal link between thimerosal and autism. These new studies are not replications so much as redundancies.

Another example of pseudosymmetry in Gellene's article concerns the space she gave to the comments of Sallie Bernard, the executive director of SafeMinds, an advocacy group dedicated, in part, to proving that mercury causes autism. Bernard was one of dozens of people who were consulted by the CDC or the authors of the study. In fact, of all those consulted and listed in the study by the authors, she is the only one who is listed as a "dissenting member." In the article I read in the Sacramento Bee, Bernard was given two full paragraphs, nearly an eighth of the entire article, to say that the study was flawed and that her view that mercury in vaccines causes all kinds of childhood disorders is equally plausible with the view that the differences found, some positive and some negative, were due to chance not thimerosal.

The flaw Bernard noted is mentioned by the authors of the study:

A majority of the selected families declined to participate or could not be located, and we were able to enroll only 30% of the subjects included for recruitment. Therefore, our findings may have been influenced by selection bias.

However, rather than bias the study against Bernard's favored belief, lead author William W. Thompson thinks it would bias the study in the other direction. "Any biases would favor an association between thimerosal and harm because parents who believed their children were hurt by vaccines would be more likely to enroll them." I don't know about that. If parents are willing to believe that their pediatricians are knowingly harming their children with vaccines, they might think that the study was a sham. I hope that the 70% who did not enroll in the study weren't afraid to do so because of what harm they wondered scientists, doctors, and drug companies might do to their children.

reader comments

September 27, 2007. My letter is prompted by your response to Oprah's utterly irresponsible and idiotic "Mothers Battle Autism" show. Your response to the MMR-causes-autism theme of the show was succinct and intelligent, as usual. However, after reading the transcript of the show (excessive teeth-grinding required), I thought it relevant to bring up another theme found in most discussions of autism: the relentless portrayal of autism from the perspective of the inconvenience, embarrassment, and anguish of the parents of autistic children, and the unspoken assumption that autistics are empty shells to be cracked open and filled, rather than actual people with functional but different minds.

One aspect of the often hysterical anti-autism movement is the glaring absence of any input from the autistic community. Autism is often portrayed by parents and "advocates" as a fate worse than death, a disease that must be stamped out at all costs. Autism can certainly be a major impairment to social functioning and independent living, but some of the arguments made for curing it sound more like attempts at quality control on the kinds of minds that should be allowed to exist. The attitude of these well-meaning, but perhaps not very empathetic, people is evident in the My Name is Autism essay. The message that this sends to the autistic community is:

 "You are defective."
"You are not human."
"You have no place in our society."
"You people only exist because we haven't found a way to get rid of you yet, but we're working on it."

The effects of these attitudes go beyond making autistic people feel angry and ashamed. They contribute to the barriers faced by autistics in society by maintaining narrow and rigid popular beliefs about the "correct" and "proper" way that people should think, process sensory data, and interact with the world. These beliefs assume that a person is "suffering" from the burden of having a mind that is different from others.

When hysterical anti-autism crusading parents and quacks are engaged by skeptics and scientists, the attitudes of the anti-autism crowd towards autistics is never addressed. The continued failure of non-autistics to question these attitudes has produced anger and exasperation in the autistic community, producing retaliations such as the tongue-in-cheek Institute for the Study of the Neurologically Typical and Michelle Dawson's more serious The Misbehavior of Behaviourists. The skeptic community does an excellent job engaging the anti-autism activists when presented with the vaccination-hysteria fringe of this group, but the root cause of this hysteria, the continued sub-humanization of autistics by these "advocates," remains unaddressed.

Name withheld at author's request

Links on this topic for those who are interested:

• Our Names Are Autism, Too (a response to the My Name is Autism essay, signed by dozens of "proud autistics" and allies)

• Autism and hate speech in the Toronto Star

• Another Parent's Take on ABA and its "Defense"

• Don't mourn for us

• Autism Network International