Esa, on Autism and Vaccines

May 1, 2009

The anti-vaccination movement has been in existence nearly as long as people have been receiving vaccinations. When the cowpox immunization to smallpox was discovered by Edward Jenner at the end of the eighteenth century, the “germ theory” of disease had not yet been established. Therefore, it is not surprising that vaccine contaminations occurred from improper production and handling, nor that a number of immunization-related deaths resulted at a rate outrageous by today’s standards, warranting the public outcry that ensued. Nonetheless, the potential benefits of this new technology far outweighed the risks, especially when compared to contemporary medical practices, making vaccination the new gold standard in medicine and earning funding support from governments across Europe (Stern & Markel, 2005).

It took eighty years for another effective vaccine to be produced, but, once the theory behind the process of vaccination was understood, the practice expanded rapidly to encompass increasing numbers of diverse diseases. In 1902, Congress passed the Biological Control Act, which established the Center for Biologics Evaluation and Research, headed by the surgeon general, after a number of children died from a diphtheria vaccine contaminated with tetanus. Since then, the responsibility for ensuring safe and effective vaccines has shifted to the National Institute of Health in 1948, followed by the Food and Drug Administration in 1972, where it remains (Junod, 2002). The widespread use of vaccines, coupled with improved sanitation and nutrition over the past two centuries, has lead to a dramatic decrease in the infant mortality rate and an increased life expectancy. In spite of this evidence of benefit, the anti-vaccination movement has persevered, often ignoring or marginalizing the impact of vaccines on these phenomena.

In 1998, Wakefield, et al. published a study in which they associated the autism and gastrointestinal symptoms of eight children with those children’s measles, mumps, and rubella (MMR) vaccinations. As this was a small, non-blinded study, which lacked a control population, it can hardly be called conclusive. Nonetheless, to allay public fears, several epidemiological studies were undertaken to address this topic, most of which repeatedly failed to confirm a causal connection between the MMR vaccine and autism (Gerber & Offit, 2009). After the publication of many of these studies, 10 of the 12 authors on the 1998 Wakefield paper issued the following statement: “We wish to make it clear that in the [1998] paper no causal link was established between MMR vaccine and autism, as the data were insufficient. However, the possibility of such a link was raised and consequent events have had major implications for public health. In view of this, we consider now is the appropriate time that we should together formally retract the interpretation placed upon findings in the (1998) paper, according to precedent. (Murch et al., 2004, p. 748)”

This statement was issued under rather disturbing circumstances. Just days before, information was uncovered by UK journalist Brian Deer that the twelve subjects in the 1998 paper had been referred to Wakefield by lawyers trying to put together a case against the pharmaceutical company that manufactured the MMR vaccine—lawyers who, it was later discovered, funded the study with over £400,000. It was also reported that Wakefield had applied for a patent for a new measles vaccine prior to the publication of his 1998 paper, given the results of which, he advocated for breaking the MMR vaccine into its components to improve safety. Most recently, evidence was presented to the United Kingdom’s General Medical Council that Wakefield fixed his data; the allegations are currently under review in a “fitness to practice” hearing.

Nevertheless, anti-vaccinationists continue to routinely cite this and other papers by Dr. Wakefield as evidence supporting their claims. What is worse is that they do so while decrying large epidemiological studies funded by the Centers for Disease Control and Prevention and the National Institute of Health (NIH) because they feel that any government agency must inextricably be tied to pharmaceutical company lobbyists. One particularly egregious example of this is Generation Rescue’s new website, fourteenstudies.org, which provides a list of studies often cited by scientists as evidence of the failure to link vaccines and autism. It then proceeds to denounce these studies, not based on their science, which is sound, but rather on the basis of perceived conflict of interest. Meanwhile the site holds up Wakefield’s 1998 study as the pinnacle of honest science by displaying it on the “our studies” page without criticism.

Interestingly, present-day anti-vaccinationists rarely subscribe exclusively to the hypothesis that autism is caused by the MMR vaccine. Instead, they choose to present whatever they consider concrete evidence, ignoring the fact that their statements are sometimes in direct contradiction, of any specious link between vaccines and autism. Of more interest still, is the fact that they will gladly point to preliminary scientific studies that seem to go their way, but dismiss larger, well-controlled studies that show the initial finding to be a statistical anomaly. Apparently, they want to usurp the credibility of science while denying the value of the scientific method. Similarly, the anti-vaccination movement has been known to hold up various government policies to defend its position, even though that same position is rife with conspiracy theories about a continuing string of cover-ups that disguise the government’s willingness to place the interests of industry above human health.

In 1997, congress passed the FDA Modernization Act, a correlate of which involved a review of the risks associated with known toxins found in food and drugs. Included on this list of items to review was thimerosal, a mercury compound used as a preservative in some vaccines. In 1999, a conglomeration of various national health and science organizations issued a joint statement with the American Academy of Pediatrics. In this statement, they discussed a number of important conclusions, including that there was no evidence of thimerosal causing harm beyond localized redness and irritation. The committee also stated the amount of thimerosal given in vaccines in infancy exceeded Environmental Protection Agency (EPA) guidelines, but reiterated that these guidelines have a built in safety factor to protect those who may be predisposed to hypersensitivity (Ball, Ball, & Pratt, 2001). Nonetheless, the committee advocated for the removal of thimerosal from vaccines, giving the following rationale: “…reducing exposure to thimerosal from vaccines is merited given the goal of reducing human exposure to mercury from all sources, the feasibility of removing thimerosal as a vaccine preservative, and the desirability of ensuring public confidence in the safety of vaccines.” (Ball, Ball, & Pratt, 2001, p. 1152)

Ironically, the statement actually served to decrease public confidence in vaccine safety. It should be mentioned that, as the thimerosal level in vaccines exceeded only the EPA’s limits and not the limits of international organizations, such as the World Health Organization, the United States was a minority when it chose to remove thimerosal from all routine childhood vaccines, which occurred in 2001. Furthermore, as the ethylmercury derivative of thimerosal had not been sufficiently studied before the FDA review, the committee based its guidelines on data from available information about methylmercury. Studies have since shown that ethylmercury is excreted from the body much more quickly than was originally thought, and thus can be tolerated in higher levels (Clarkson, 2002).

Due to continued public concern over vaccine safety, and accusations that the government agencies involved in the initial review had too much vested interest in maintaining the public perception of vaccine safety to remain objective, independent scientific institutions, the National Academy of Science and the Institute of Medicine, were asked to conduct their own review of thimerosal safety. These groups established a committee to study the issue and concluded that the “evidence is inadequate to accept or reject a causal relationship between thimerosal exposures from childhood vaccines and the neurodevelopmental disorders of autism, ADHD, and speech or language delay” in 2001. This, of course, led to a new round of parent outcry and the funding of a number of major studies of the topic.

In light of the results of these new studies, the great majority of which found no link between immunization with thimerosal-containing vaccines and autism, a second Immunization Safety Review Committee was formed in 2004 to address the topic. It concluded “the evidence favors rejection of a causal relationship between thimerosal-containing vaccines and autism”. Given this statement, one would have expected this branch of the autism controversy to fade, but, like the MMR vaccination controversy, this issue has its champion scientists who can do no wrong in the eyes of the anti-vaccination movement. Their names are Mark and David Geier.

This father-son research team provides the literature with its primary source of epidemiological data that seems to support the hypothesis that thimerosal in vaccines cause autism (Geier & Geier, 2004). Their data, however, did not sway the Immunization Safety Review Committee’s decision. After examining the Geiers’ study, the committee concluded that, not only did they improperly analyze data from the Vaccine Adverse Event Reporting System (VAERS), which was the primary source of information for their study, they also confused statistical techniques in their paper and refused to provide their data to other groups to analyze. Nonetheless, the Geiers’ original research paper continues to be cited in current anti-vaccination literature. Furthermore, Mark Geier is routinely called as an expert witness for parents seeking compensation for their “vaccine-injured” children. In at least one instance, his testimony was stricken from the record because, as a geneticist and obstetrician, he was unfit to provide testimony on questions of neurology, though he happily did so, getting the science wrong nearly every step of the way.

Of course, parents continue to seek out and follow the advice given by the Geiers. This is likely because their theories provide parents with both a cause for their child’s autism and a potential mode of treatment. If autism actually was a form of mercury poisoning caused by the thimerosal in vaccines, then it is possible that a treatment called chelation therapy, which, when used properly, removes heavy metals from the body, could alleviate the symptoms of autism. Unfortunately, this is not standard medical practice because standard medical theory does not include thimerosal as a cause for autism. Therefore, parents seeking chelation therapy for their child tend to receive it from some alternative medical practitioner and, on occasion, the procedure is not followed properly and severe side effects, including death, result (Atwood, Woeckner, Baratz, & Sampson, 2008).

Worse still, if that is possible, the Geiers have continued to perform research on this issue. They have expanded and revised their hypotheses and now explain the different prevalence rates between the sexes by claiming that males continue to be exposed to increased levels of mercury beyond what is seen in females because it binds to testosterone and cannot be processed and removed by the body. This has the added benefit of explaining why, except in a few anecdotal stories, chelation therapy does not cure a child of autism—the chelating agent cannot remove the mercury that remains bound to testosterone in the body. Working within this paradigm, the Geiers are now advocating the use of the drug Lupron, a gonadotropin-releasing hormone agonist, in combination with chelation therapy (Geier & Geier, 2006). The use of this therapy in children effectively amounts to chemical castration.

Obviously, a position this extreme cannot be the face of the “vaccines cause autism” anti-vaccination movement. Instead, the media appearances of late have been handled by Jenny McCarthy and Jim Carrey on behalf of the group Generation Rescue, which was appropriately renamed “Jenny McCarthy and Jim Carrey’s Autism Organization” just days ago. Of course, their positions really are nearly as extreme, but they are more tactful in presenting their arguments and know when they have gone too far. For example, when on Larry King Live for “Autism Awareness Day” this year, Jenny emphasized that no one has ever asked that children not be vaccinated, but rather the movement advocates for a return to the 1989 vaccination schedule, in which fewer shots were given. Unfortunately, she seems to miss the point that hundreds of parents are now refusing to get their children vaccinated in light of the propaganda presented by groups like Generation Rescue and Defeat Autism Now, and that measles rates are now the highest they have been in over a decade, largely due to spread in unvaccinated individuals.

With science having debunked the thimerosal and MMR controversies, it seems that this idea of “too many, too soon” that Jenny has expressed will be the new line of the anti-vaccination movement. This position, of course, is much more difficult to study scientifically. Furthermore, many of the anti-vaccinationists are currently saying that the only evidence they will accept as sufficient to refute their claims is a study of autism occurrence in vaccinated compared to unvaccinated individuals. This statement highlights the scientific illiteracy present in the movement, as, in the face of current scientific knowledge of the safety and effectiveness of vaccines, a randomized study of this sort would be unethical.

Given the state of scientific consensus and the potential ramifications of therapies given within various anti-vaccination paradigms, (i.e. leaving your children unprotected in the face of preventable disease, or subjecting them to dangerous chemical treatments) it is no small wonder that the movement has maintained popularity and remained in public consciousness. Indeed, for those without a personal interest in autism, the disorder is all too often equated with vaccines, even in otherwise well-informed individuals. Why is this? Those on the anti-vaccination fringe will tell you it is because the truth is finally coming out in spite of attempts by government and science to cover it up. Conspiracy theories, such as this, are traditionally fringe positions and likely remain so in the case of the anti-vaccination movement. However, when examined critically, the anti-vaccination position falls apart in the face of overwhelming scientific evidence without the conspiracy crutch. Why, then, does the position continue to stand?

Parents with no scientific background have seen their children get immunizations and autism diagnoses too close together too many times. It is human nature to look for patterns and, unfortunately, the Jenny McCarthies of the world are all too glad to prolong their time in the limelight to provide parents with correlational patterns they may otherwise never have seen. Furthermore, it is, of course, in the nature of parents to want to help their children. Therefore, they are willing to listen to anyone with a suggestion without considering the science behind it. They walk uncritically into pseudoscience holding the phrase “What’s the harm?” as a talisman in their hearts, completely unaware of the harm that the movement has done.

~ Esa

And yes, this was a school paper.

Advertisements

One Response to “Esa, on Autism and Vaccines”

  1. Esattezza Says:

    I thought you all might like the full citations:

    Atwood, K. C., Woeckner, E., Baratz, R. S., & Sampson, W. I. (2008). Why the NIH Trial to Assess Chelation Therapy (TACT) should be Abandoned. Medscape Journal of Medicine, 10(5), 115.

    Ball, L.K., Ball, R., & Pratt, R.D. (2001). An Assessment of Thimerosal Use in Childhood Vaccines. Pediatrics, 107(5), 1147–1154.

    Berger, A. (2004). MMR: What They Didn’t Tell You. BMJ, 329(7477), 1293.

    Clarkson, T.W. (2002). The Three Modern Faces of Mercury. Environmental Health Perspectives, 110,11-23.

    Geier, D.A., & Geier, M.R. (2004). A Comparative Evaluation of the Effects of MMR Immunization and Mercury Doses from Thimerosal-containing Childhood Vaccines on the Population Prevalence of Autism.” Medical Science Monitor, 10(3), 33-9.

    Geier, D.A., & Geier, M.R. (2006). A Clinical and Laboratory Evaluation of Methionine Cycle-Transsulfuration and Androgen Pathway Markers in Children with Autistic Disorders. Hormone Research, 66(4), 182–8.

    General Medical Council (2009, March 30). Press Release: Wakefield. Retrieved from http://www.gmcpressoffice.org.uk/apps/news/events/index.php.

    Gerber, J.S., & Offit, P.A. (2009). Vaccines and Autism: A Tale of Shifting Hypotheses Vaccines, 48, 456-461.

    Immunization Safety Review Committee, Board on Health Promotion and Disease Prevention, Institute of Medicine. (2001). Immunization Safety Review: Thimerosal-Containing Vaccines and Neurodevelopmental Disorders. Washington, DC: National Academy Press.

    Immunization Safety Review Committee, Board on Health Promotion and Disease Prevention, Institute of Medicine. Immunization Safety Review. (2004). Vaccines and Autism. Washington, DC: The National Academies Press.

    Junod, S.W. (2002). Biologics Centennial: 100 Years of Biologics Regulation. Update, the bimonthly publication of the Food and Drug Law Institute, Nov/Dec 2002.

    Murch, S.H., Anthony, A., Casson, D.H., Malik, M., Berelowitz, M., Dhillon, A.P., et al. (2004). Retraction of an interpretation. Lancet, 363(9411), 747-9.

    Stern, A.M., & Markel, H. (2005). The History of Vaccines and Immunization: Familiar Patterns, New Challenges. Health Affairs, 24(3), 611-621.

    Wakefield, A.J., Murch, S.H., Anthony, A., Linnell, J., Casson, D.M., Malik, M., et al. (1998). Ileal-lymphoid-nodular Hyperplasia, Non-specific Colitis, and Pervasive Developmental Disorder in Children. Lancet, 351, 637–41.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: