Exposing the Vaccine-Autism Myth
Total Page:16
File Type:pdf, Size:1020Kb
Mercury Rising Exposing the Vaccine-Autism Myth MATTHEW .N._O_.A__¥_-A N p a ji_cl J _E S_ S _E D_A_ L L E RY ON JUNE 11, 2007. NEARLY 5,000 PARENTS OF thimerosal and autism; (2) a number of well con- autistic children filed a lawsuit against the federal trolled studies have failed to uncover any correla- government, claiming that childhood vaccines tion between the delivery of the vaccines and the (specifically the mercury-containing thimerosal in oaset of autism; (3) even if some correlation the vaccines) caused their children's autism. The existed there are a number of alternative expla- previous year the New York Times ran a col- nations for the correlation that do not assume umn that was skeptical of the alleged link any causal relationship between the vacxine and between autism and vaccines. It generated autism; (4) much anention has !:)een given to a the following comment on an Internet mes- possible goveniment cover up, which is certainly sage board, typical of the anecdotal analyses of concern if tnje but is otiierwise independent that perpetuate the claim; of the problems witli claims of a link lieriveen thimerosal and autism; and (5) the type of public You say, "There is no pn:i\^en link" between mercury hysteria manifested in the current controversy Ls and autism. There also is "no proven link" between not new and we would l^e well served to leam going outside in the rain and cold without a hat or ftom similar controversies of recent times. coat and getting the sniffles. Look at the data: the epidemic of autism mirrore tfie adminisiration of vacdnes with mercury. Now tfiat they are off the RAercury, Thimerosal, and the Potential for Harm shelves (more or less), the cases are going doun. Sdence lias tokl us uiiequi\ix:ally tliat mercury is bad for our bodies. In sufficient doses, mercury Here we see how the writer dismisses sdentif- kills cells that it contacts, causes neurological ic evidence that fails to support a link Ixjtween damage in humans and other animals, and gen- cold and illness and vacdnes and autistn in favor erally wreaks havoc on living things. Yet since of her personal experiences. And tlie vaccine- tlie 1930s, thimerosal has been used as a preser- autism cxjntroversy is not constrained to a small vative in vacdnes.^ One of the breakdown pRxi- fringe group of parents or advocates. Increasingly, ucts of thimerosal Ls ethylmercury, wMch is an people of position and power are leaping into oi^anic compound of mercury. Public concern the fray, spurred on by vocal groups demanding about thimerosal Ls certainly understandable, but action. For example, an article by Robert F. does this mean that concern about a link Kennedy, Jr. appeared in a June 2005 issue of between vacdnes and autism is justified as well? Rolling Stone magazine^ that alleged thimerosal- In a word, no. Mercury miglit do a number of containing vacdnes were at the heart of the nasty things to the human body, and concern autism epidemic and, moreover, that the govern- about it is therefore justified, but that does nc« ment was aware of this and actively enj^ged in mean it causes autism. a cover-up. Ethylmercury is not tlie same thing as its This article makes five points concerning the cousin, metliylmercury. Cumulative and high relation between thimerosal-containing vacdnes doses of metliylmercury can produce renal and and autism: (1) the dangers of mercury are well neurologic damage. It can build up in the brain established, but tliis does not lead inexorably to and stay in the body for a long time. a relationsliip between vaccines containing Ethylmercury is more, well, mercurial. It is f VOLUME 13 NUMBER 3 2007 expelled riipidly from the bcxly and it in the U.S., ba.sed on a request from does not accumulate. Nevertheless, guide- tlie Food and Drug Administration lines for the ingestion of ethylmercury (FDA) (it remains in some influenza vac- were based on those for methylmercury. dnes and in some vacdnes outside of Around the same time these guidelines the U.S.). The request was made as a were formalized, children were receiv- preaiLitionary measure, and not ing more vaccines that contained lTecau.se there was evidence to accept thimerosal. For example, in tlie early or rejeci a causal relatioaship hietween 1990s the Haemopliilus influenzae b thimerosal and autism. (Thimerosal is and hepatitis B became staple features still used during manufacture of some of the vaccine schedule for vaccines to ensure sterility, but infants, which already included the trace amounts remaining another thimerosal-ajntaining are 50 times lower than when vaccine (diphtheria tetanus and thimerosal is used as a pre- variants). Based on tlie very conser- servati\'e.) Since the FDA decision, a vative guidelines established by the numlxjr of research reports published Environmental Protection Agency in some of tlie most esteemed peer- (EPA), it was concluded that by age reviewed journals in the world have two some children might be receiv- failed to find any relation Ixftween ing excessive levels of ethylmercury ttiinierosixl and autism. Despite tliese when cx)nsidered in the context of negative findings and the removal known risks of methylmercury expo- of thimerosal from vaccines, par- sure.^ ents, politicians and health profes- sionals remain alarmed that chil- Agaiast this backdrop enter sky- dren are at risk. rocketing rates of autism diagnoses. In California, the Department of Much is at stake in this debate. Developmental Services reported a Based on the assumption that metals 273% increase from 1987 to 1998 in such as mercTjry are causing autism, the number of individuals served some parerus are avoiding vacdna- under the category of autism.** Surely ti(5ns altogetlier. Otliers have sought tliis increase in rates was caused by treatments like chelation tlierapy, an environmental source, right'' In which uses spedal chemicals to rid 2001, the Instimte of Medicine (IOM) tlie Ixxiy of heavy metals following Immunization Safety Review acute poisoning. However, chelation Committee held a public meeting to is not a risk-free procedure and address the link between one envi- should not be undertiiken lightly. In ronnient:il source—thimerasal—^and August of 2005, a Pittsbuigh, PA area autism. At tlie meeting, Mark Blaxill, a newspaper reported that a 5-year old board member of a nonprofit organi- boy with autism died following zation dedicated to investigating the chelation therapy. Finally, there are risks of mercury exposure, presented a ongoing class action lawsuits again^ graph showing the estimated cumula- the manufacturei^ of vacdnes. These tive dose of thimerosal to the estimated lawsuits could potentially endanger the prevalence of autism in California.^ The production and distribution of effective vac- increasing trend lines during the early 1990s dnes according to well-established prato- were right on top of each other, about as cols, putting scores of yoLing cMdren at risk. dose as you can get to perfect correlation in ecological data, Such oRierly correlations are Evidence of Harm all that it takes to convince the uncritical Let's begin with the hyjxjthesis that eye. thimerasal is one of the causes of autism Even before the IOM meeting, thimerosal and that it is the main culprit in the was removed as a preservative in vaccines increased incidence of autism during the 1990s. This is a plausible hypothesis, but as Karl healtli-care professional, p)arent, or even some- Popper taught tjs, a good sdentific hypothesis one tr>'ing to prove a point "^ can enter data into mast be falsifiable. That is, it must be possible to the VAERS. There is no way to verify diagnases, conceive of evidence that would prove it v.Tong. identify mistakes in filing, or sul^stantiate causal What evidence might suggest that tiie thimerosal h>potlieses. hypotliesls is false? For obvious ethical reasons, The inseparably flawed studies by the Geiers we can't perform the kind of gold-standard prompted a strong relxike from the Centers for experiment—^a randomized double-blind study— Disease Control (CDC) and by tlie American which would most con\'incingly indicate the lack Academy of Pediatrics." Simply put, the VAERS of a causal relation. We must rely on natural data may be useHil to raise some potential ques- experiments. One such experiment was occa- tioas about a phenomenon, but it certainly cannot sioned by the removal of thimerasal in Denmark be used to prove a hypothesis. Studies tliat use in 1992. If the thimerosal hypothesis were false, methods ajnsistent with well-established sdentific we would not expea to see dianges in the rates standards have failed to find any association of autism following tlie removal of tfiimerosal. In between tliinierasal and autism. In 2004, tlie fact, the results were more robust: despite the Institute of Medicine conduded, "Given the lack removal of thimerasal, the rates of autism contin- of direct evidence for a biological mechanism and ued to climb. And not only in Denmark but in Sweden, too, where thimerosal was removed at the faa that al! well-designed epidemiologjcal about the same time.^ studies provide evidence of no association between thimertsal and autism, the committee Another way the thimerosal hypothesis could tecommencLs that cost-benefit assessments regard- \je falsified Is if it could be shown that tliere is ing the use of thimerosal-a^ntaining veisus no link between the amount of thimerosal expo- tliimerosal-free vacdnes and odier biological or sure and the likelihood of autism. That is, we l^hiirmaceutical products, whetlier in the United would ask if tliere is a dose-response relation States or other countries, should not include between thimerosal exposure and developmental autism as a potential rlsk,"'^ problems.