History Thiomersal controversy

reports of autism cases per 1,000 children grew dramatically in u.s. 1996 2007. unknown how much, if any, growth came changes in autism s prevalence.

although intended increase public confidence in vaccinations, decision remove thiomersal instead led parents suspecting thiomersal cause of autism. concern on vaccine-autism link grew confluence of several underlying factors. first, methylmercury had decades been subject of widespread environmental , media concern after 2 highly publicized episodes of poisonings in 1950s , 1960s in minamata bay, japan industrial waste , in 1970s in iraq fungicide contamination of wheat. these incidents led new research on methylmercury safety , culminated in publication of array of confusing recommendations public health agencies in 1990s warning against methylmercury exposure in adults , pregnant women, ensured continued high public awareness of mercury toxicity. second, vaccine schedule infants expanded in 1990s include more vaccines, of which, including hib vaccine, dtap vaccine , hepatitis b vaccine, have contained thiomersal. third, number of diagnoses of autism grew in 1990s, leading parents of these children search explanation apparent rise in diagnoses, including considering possible environmental factors. dramatic increase in reported cases of autism during 1990s , 2000s largely attributable changes in diagnostic practices, referral patterns, availability of services, age @ diagnosis, , public awareness, , unknown whether autism s true prevalence increased during period. nevertheless, parents believed there growing autism epidemic , connected these 3 factors conclude increase in number of vaccines, , mercury in thiomersal in vaccines, causing dramatic increase in incidence of autism.

advocates of thiomersal-autism link relied on indirect evidence scientific literature, including analogy neurotoxic effects of other mercury compounds, reported epidemiologic association between autism , vaccine use, , extrapolation in vitro experiments , animal studies studies conducted mark geier , son david geier have been cited research parents advocating link between thiomersal , autism. research geier has received considerable criticism methodological problems in research, including not presenting methods , statistical analyses others verification, improperly analyzing data taken vaccine adverse event reporting system, either mislabelling or confusing fundamental statistical terms in papers, leading results uninterpretable .

publicity of concern

several months after recommendation have thiomersal removed vaccines published, speculative article published in medical hypotheses, non-peer-reviewed journal, parents launched parental advocacy group safeminds promote theory thiomersal caused autism. controversy began gain legitimacy in eyes of public , gained widening support within elements in autism advocacy community in political arena, u.s. representative dan burton openly supporting movement , holding number of congressional hearings on subject.

further support association between autism , thiomersal appeared in article robert f. kennedy, jr. in magazines rolling stone , salon.com alleging government conspiracy @ cdc meeting conceal dangers of thiomersal protect pharmaceutical industry, , book written david kirby, evidence of harm, dramatizing lives of parents of autistic children, both authors participating in media interviews promote work , controversy. although allegations kennedy denied , senate committee investigation later found no evidence substantiate serious allegations, story had been publicized leveraging kennedy s celebrity. salon magazine subsequently amended kennedy s article 5 times due factual errors , later retracted on january 16, 2011, stating works of critics of article , evidence of flaws in science connecting autism , vaccines undermined value of article editors.

meanwhile, during time of increased media publicity of controversy, public health officials , institutions did little rebut concerns , speculative theories being offered. media attention , polarization of debate has been fueled personal injury lawyers took out full-page ads in prominent newspapers , offered financial support expert witnesses dissented scientific consensus there no convincing evidence link between thiomersal , autism. paul offit, leading vaccine researcher , advocate, has said media has tendency provide false balance perpetually presenting both sides of issue when 1 side supported evidence , thereby giving platform spread of misinformation.

despite consensus experts there no link between thiomersal , autism, many parents continue hold belive such link exists. these parents share viewpoint autism not treatable, curable through biomedical interventions , have been frustrated lack of progress more mainline scientists in finding cure. instead, have supported alternative community of like-minded parents, physicians , scientists promote belief. mindset has taught these parents challenge expertise mainstream scientific community. parents have been influenced large number of online anti-vaccination websites present alternative source evidence using pseudoscientific claims. these websites use emotional appeals gather support , frame controversy adversarial dispute between parents , conspiracy of doctors , scientists. advocates thiomersal-autism link have relied on celebrities model jenny mccarthy , information presented on don imus imus in morning radio show persuade public cause, instead of relying on dry scientific papers , scientists. mccarthy has published book describing personal experience autistic son , appeared on oprah winfrey show promote hypothesis of vaccines causing autism. bitterness on issue has led numerous threats made against cdc researchers offit, increased security placed cdc in response these threats.