Lentis/Social Resistance to Vaccination: Thiomersal and Autism


Compulsory vaccination has faced widespread resistance in the U.S. since its introduction in the 1900's, largely based on claims that vaccines have negative health effects. Even after these claims have been scientifically rejected, as in the case of thiomersal and autism, the initial fear that these allegations incited still hold fast in the public psyche.

An in depth understanding of vaccination requires a level of scientific knowledge above that of the average citizen. This lack of full understanding creates a sense of doubt about the safety and efficacy of vaccination. The innate inability of scientific research to make definitive claims adds to this sense of doubt and lowers confidence in positive research findings. There is additional uncertainty surrounding the vaccination and autism debate because there is very little known about the cause of autism.

As previously prevalent diseases such as measles and polio are now managed through vaccination, people have become less concerned with the personal and public health benefits of vaccination and more concerned with the possible side effects. While the proponents of vaccination present their claims in a technical format, the opponents of vaccination use emotionally charged arguments and the media to voice their beliefs. This dynamic combination of factors makes the case of thiomersal in vaccines one example of when scientific data alone does not carry enough weight to generate social acceptance of a technology.

History of Vaccination AcceptanceEdit

The first inoculation is believed to have occurred in China in 1000 CE when the son of a Chinese statesman was inoculated against smallpox via powdered smallpox scabs blown into his nostrils.[1] The first traditional vaccine was made against smallpox as well, approximately 800 years later in 1796. When the smallpox vaccine was developed by Edward Jenner, the mortality rate of smallpox patients was approximately 30%.[2] Although there was a high risk of infection, many were initially reluctant to be inoculated because the existing medical methodology favored treatment over prevention and the original vaccines contained live cowpox virus.[3] As vaccine manufacturing improved and people began to see the immense health benefits, public acceptance grew rapidly. By 1979 the World Health Organization deemed smallpox eradicated, a huge milestone for public health.[4]

Since 1796, more vaccines have been developed for many dangerous diseases, from diphtheria to measles to mumps. In the 1990s, the number of vaccines recommended for the childhood vaccination schedule doubled.[5] Today, children can be given as many as 21 immunizations in the first 15 months of life.[6]

As vaccines continue to lower the incidence of infectious diseases, citizens have become less interested in the consequences of preventable illnesses and more concerned about potential risks associated with vaccines. Because all patients must legally be made aware of potential side effects, no matter how rare, any illness following immunization is often associated with the vaccine. Although there are always risks attributable to vaccination, many perceived side effects are unrelated and occur after vaccination by coincidence.

Thiomersal and Autism DebateEdit

Thiomersal is a mercury-based preservative used to prevent the growth of bacteria and fungi in multi-dose vials of vaccines by inactivating organisms and toxins and desterilizing the vaccine.[7] The necessity for preservatives like thiomersal became clear in Australia in 1928, when Dr. Ewing George Thomson injected 21 children with previously used vials of diphtheria vaccine serum in Australia. Twelve of the 21 children given the vaccination in this round of doses died of staphylococcus infection, which could have been prevented by the use of a preservative. Following this incident, the Royal Commission recommended that all multi-dose vials should contain preservatives.[8]

As their use has increased since then, preservatives have faced scrutiny due to their chemical content. In 1998, a paper by Andrew Wakefield was published in The Lancet claiming to have found a distinct correlation between autism and the measles, mumps, and rubella (MMR) vaccine.[9] Wakefield and his colleagues claimed that autism-like symptoms were observed within two weeks of the MMR vaccination. The Centers for Disease Control and Prevention (CDC) and American Academy of Pediatrics (AAP) responded by recommending the reduction of thiomersal in children's vaccines as a precautionary measure.[10] As resistance continued to grow, thiomersal was removed from or reduced in all vaccines manufactured for the U.S. in 2001.[11] However, multiple studies published in peer reviewed journals found no evidence associating autism and the MMR vaccine containing thiomersal; highly respected scientists were unable to replicate Wakefield’s data.[12]

This created a sense of doubt leading to a federal investigators of Wakefield’s credibility. Soon thereafter, the 1998 Wakefield study was deemed to be fraudulent and investigations found that Andrew Wakefield had abused the children.[13] Although Wakefield's research was falsified and the government has continued to assure the public that thiomersal-containing vaccines are safe, parents of children with autism continue to rally around the idea that the disease was induced by vaccination.

Opposition to ThiomersalEdit

The opponents of vaccination argue that thiomersal and other vaccine impurities can directly cause autism. Despite the lack of scientific evidence backing this claim, they continue to press for the elimination of these toxins from vaccines. Another faction in the opposition believes that children receive too many vaccines; they advocate for a change in youth vaccination schedules. The anti-vaccination movement has emerged as a result, bringing the issue to the public eye through the use of the media and publicity campaigns.

Generation RescueEdit

Jenny McCarthy

Generation Rescue is a nonprofit organization dedicated to researching causes of autism and helping children receive treatment. The organization is comprised of scientists, physicians, and parents who believe that autism is caused by environmental toxins, including those found in vaccines. Its purpose is to educate parents about autism prevention techniques and how to improve their children’s conditions through proper treatment.[14]

Jenny McCarthy, a leader in the anti-vaccination movement and the current president of Generation Rescue believes that children receive “too many vaccines, too soon, many of which are toxic.”[15][16] In an interview, McCarthy claimed there is a direct link between thiomersal and autism, noting that, “In 1983 the shot schedule was 10. That’s when autism was 1 in 10,000. Now there are 36, and autism is one in 150. All arrows point to one direction."[17] Through her involvement in Generation Rescue, she hopes to raise awareness about dangerous vaccine impurities.[18]

In March 2008, Generation Rescue joined other national autism advocacy groups and led the ‘Green Our Vaccine’ march in Washington D.C., with the hopes of bringing public attention to the issue.[19] The Green Our Vaccines rally voiced that if there is any possibility that autism is associated with vaccine impurities, then the toxins must be eliminated.[20] The frequent appearances of McCarthy on talk shows and at rallies has kept the issue in the public eye and overshadowed the scientific evidence that has discredited the opposition altogether.

Moms Against MercuryEdit

Moms Against Mercury (MAM) is a nonprofit organization lead by mothers dedicated to bring awareness while educating the public of the dangers of thiomersal.[21] They advocate for the elimination of thiomersal in vaccines to make them safer and mercury-free.[22] MAM was founded by Amy Carson, who has an autistic son. Carson claims that her son was born a healthy child until he received multiple vaccines growing up.[23] When he began to show symptoms of autism, Carson concluded that her son had been poisoned by mercury from the vaccinations. Carson organized MAM to increase public awareness of the issue and educate parents about the harms of vaccines containing mercury preservatives.[24]

MAM has met with Congressmen, Senators, and activists across the country to spread the word about thiomersal and other dangerous vaccine components.[25] The organization has appeared in many newspapers and local network news stories, continuing to proliferate the media with anti-vaccine sentiments.[26] MAM's determination is obvious in their motto, “Fight for truth and justice for our children… And yours."[27]

Federal Support of VaccinationEdit

There is a growing body of evidence rejecting the correlation between thiomersal in vaccines and the development of autism in children. Although opposition groups have continued to publicize their claims in spite of this research, many groups continue to work towards addressing these concerns and proving that vaccinations are safe. Government agencies such as the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) are two such groups that aim to inform the public of the truth about the hazards of vaccination and their important benefits. These organizations are one driving force behind the ongoing scientific research attempting to determine whether or not there is a causal link between thiomersal and autism.

Federal AgenciesEdit

Centers for Disease Control

Currently, about 1 in every 50 children has autism, a number which has risen since 1990's. While there are many who believe that this rise can be attributed to the use of thiomersal as a preservative in vaccinations for children, numerous studies prove this to be untrue.[28][29] The CDC is one agency with expertise on the topic of vaccinations and their negative effects, with teams of scientists and researchers conducting studies on the nation’s top health concerns.

The CDC is primarily responsible for analyzing the scientifically proven health effects of thiomersal use in vaccines. With a core value of protecting the health of all Americans, the CDC has run studies and scientific reviews to determine whether there is a causal relationship between thiomersal and autism.[30] One such study, the Immunization Safety Review, concluded that “the body of epidemiological evidence favors the rejection of a causal relationship between the MMR vaccine and autism."[31] Another report issued by the CDC in November 1999 stated that “the demonstrated risks for not vaccinating children far outweigh the theoretical risk for exposure to thimerosal-containing vaccines during the first 6 months of life.”[32]

In 1999, the FDA also conducted a review of thiomersal in childhood vaccines, which failed to find any evidence of a correlation with autism. This review was undertaken as part of the FDA Modernization Act (FDAMA) of 1997, which included an analysis of overall childhood exposure to ethylmercury (in thiomersal) in the first six months of life, since to date only methylmercury had been studied. This study found that in some cases, the levels of ethylmercury were higher than the recommended levels for methylmercury put out by the Environmental Protection Agency (EPA). Following this, the CDC and FDA, among other public health agencies, urged for the removal of thiomersal from vaccines while further studies were undertaken. Later studies, however, found no negative health effects from ethylmercury.[33]

National Vaccine Injury Compensation ProgramEdit

The Vaccine Injury Compensation Program (VICP) was created on October 1, 1988 through the National Childhood Vaccine Injury Act of 1986 by the Department of Health and Human Services (HHS) Health Resources and Services Administration. Although VICP also works to regulate the supply and cost of vaccines, the program is mainly recognized as being the no-fault alternative way to give compensation to patients and the families of those injured by vaccines.[34]

The money used for compensating victims under VICP is kept in the Vaccine Injury Compensation Trust Fund and managed by the Department of the Treasury. A $0.75 excise tax on each dose of routine vaccines recommended by the CDC maintains this fund. When a claim is filed, the U.S. Court of Federal Claims decides if the family has enough evidence to receive compensation. Throughout the claims review process, the Department of Justice and HHS are also involved.[35]

VICP is a critical component of the thiomersal and austism debate because all claims arguing that thiomersal caused injury or death must be made with VICP before civil litigation. Approximately 5,000 families have filed claims of vaccine-induced autism, even though there is no scientific evidence of this relationship. VICP has never ruled in favor of a claim that argues the autism-vaccine link.[36]


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