User:Karliegh.Miller/Vaccines and autism

vaccines

Extensive investigation into vaccines and autism spectrum disorder has shown that there is no relationship between the two, causal or otherwise, and that vaccine ingredients do not cause autism. The American scientist Peter Hotez researched the growth of the false claim and concluded that its spread originated with Andrew Wakefield's fraudulent 1998 paper, and that no prior paper supports a link.

Despite the scientific consensus for the absence of a relationship and the retracted paper, the anti-vaccination movement at large continues to promote theories linking the two. A developing tactic appears to be the "promotion of irrelevant research [as] an active aggregation of several questionable or peripherally related research studies in an attempt to justify the science underlying a questionable claim."

Claimed mechanisms

Up close explanation of a vaccine.

The claimed mechanisms have changed over time, in response to evidence refuting each in turn. The CDC published updated statistics on autism in children for the year 2020. It states that in the year 2000, there were 1 in 150 children who were born in 1992 diagnosed with autism. In 2020, they found 1 in 36 children born in 2012 were diagnosed with autism. Anti-vaccination groups believe this to be the increased number of vaccines in children. Although there has been an increase in vaccines, there has been an increase in autism screenings. It is clear from the literature and the CDC the increased number of children diagnosed with autism is due to the increase in ways to diagnose it. The anti-vaccine groups credit ingredients in the vaccines to be the connection to autism. Some of the most mentioned ones are thiomersal, aluminum adjuvants, and formaldehyde. The MMR vaccine will be explained as well. Celebrity and social media involvement seem to play a role in the anti-vaccine movement.

Autism Screening History

• In the early 2000s, evidence-based tools were being used for children as early as 36 months to help with the diagnosis of autism, and parents of children were able to identify signs of autism by the time the child turned 2.
• In 2001, the Modified Autism Checklist for Toddlers (M-CHAT) was used and could diagnose children with signs of autism at 24 months.
• In 2006, the American Academy of Pediatricians mandated screening, specifically for autism, at a child's 18-month checkup and later mandated for the 24-month visit as well.
• As of May 2024, the CDC mentioned that healthcare workers, community members, and even schools can screen for autism. The diagnosis of autism in a child by the age of 2 conducted by a professional is evaluated as very reliable.

Vaccine overload

[edit] Further information: Vaccine hesitancy § Vaccine overload

Following the belief that individual vaccines caused autism was the idea of vaccine overload, which claims that too many vaccines at once may overwhelm or weaken a child's immune system and lead to adverse effects. The Children's Hospital of Philadelphia Vaccine Education Center compiled a list of vaccines recommended to children throughout history. They found that from 1985-1994, the recommended number of vaccines totaled to eight. The schedule for 2011 to 2020 revealed the recommended number of vaccines totaled to fourteen. Vaccine overload became popular after the Vaccine Injury Compensation Program in the United States accepted the case of nine-year-old Hannah Poling. Poling had encephalopathy, putting her on the autism spectrum disorder, which was believed to have worsened after getting multiple vaccines at nineteen months old. There have been multiple cases reported similar to this one, which led to the belief that vaccine overload caused autism. However, scientific studies show that vaccines do not overwhelm the immune system. In fact, conservative estimates predict that the immune system can respond to thousands of viruses simultaneously. It is known that vaccines constitute only a tiny fraction of the pathogens already naturally encountered by a child in a typical year. Common fevers and middle ear infections pose a much greater challenge to the immune system than vaccines do. Other scientific findings support the idea that vaccinations, and even multiple concurrent vaccinations, do not weaken the immune system or compromise overall immunity and evidence that autism has any immune-mediated pathophysiology has still not been found.

Impact of vaccines on Diphtheria, Meningococcal, Polio, Haemophilus Influenzae type B, Measles, and Pertussis.

Vaccines recommended from 1985-1994

• Diphtheria
• Tetanus
• Pertussis
• Measles
• Mumps
• Rubella
• Polio
• Hib
• Hepatitis B (1991)

Vaccines recommended from 2011-2020

• Diphtheria
• Tetanus
• Pertussis
• Measles
• Mumps
• Rubella
• Polio
• Hib
• Hepatitis B
• Varicella
• Hepatitis A
• Pneumococcal
• Influenza
• Rotavirus

Diphtheria, Tetanus, and Pertussis were given together as the DTap. Measles, Mumps, and Rubella were given together as MMR.

Thiomersal

Thiomersal is an antifungal preservative used in small amounts in some multi-dose vaccines (where the same vial is opened and used for multiple patients) to prevent contamination of the vaccine. Thiomersal contains ethylmercury, a mercury compound that which is related to, but significantly less toxic than, the neurotoxic pollutant methylmercury. Despite decades of safe use, public campaigns prompted the CDC and the American Academy of Pediatrics (AAP) to request vaccine makers to remove thiomersal from vaccines as quickly as possible on the precautionary principle. Thiomersal is now absent from all common United States and European Union vaccines, except for some preparations of influenza vaccine. (Trace amounts remain in some vaccines due to production processes, at an approximate maximum of 1 microgramme, around 15% of the average daily mercury intake in the US for adults and 2.5% of the daily level considered tolerable by the World Health Organization [WHO].) The action engendered concern thiomersal could have been responsible for autism.

The idea that thiomersal was a cause or trigger for autism is now considered disproven, as incidence rates for autism increased steadily even after thiomersal was removed from childhood vaccines. The cause of autism and mercury poisoning being associated is improbable because the symptoms of mercury poisoning are not present and are inherently inconsistent with the behaviors or symptoms of autism. There is no accepted scientific evidence that exposure to thiomersal is a factor in causing autism. A study by the CDC exploring mercury poisoning in vaccines concluded no signs of poisoning were present.

Under the U.S. Food and Drug Administration (FDA) Modernization Act (FDAMA) of 1997, the FDA condcted a comprehensive review of the use of thiomersal in childhood vaccines. Conducted in 1999, this review found no evidence of harm from the use of thiomersal as a vaccine preservative, other than local hypersensitivity reactions. Despite this, starting in 2000, parents in the United States pursued legal compensation from a federal fund arguing that thiomersal caused autism in their children. A 2004 Institute of Medicine (IOM) committee favored rejecting any causal relationship between autism and vaccines containing thiomersal and rulings from the vaccine court in three test claims in 2010 established the precedent that thiomersal is not considered a cause of autism.

Aluminium Salts Adjuvants

As mercury compounds in vaccines have been definitively ruled out as a cause of autism, some anti-vaccine activists propose aluminium salts adjuvants as the cause of autism. Aluminium adjuvants, simulates immune receptors and causes a strengthened response to the antigen in a way that is natural to the body. Aluminium adjuvants can be used in the form of soluble salts, alumina, and hydroxl. This is based in part on the erroneous popular belief that aluminium salts cause Alzheimer disease. There is no substantial scientific evidence that aluminium salts adjuvants are linked to autism. When confirming that aluminium adjuvants are not dangerous in vaccines, it was concluded that there was no traces of aluminium in the children's hair or blood over the minimum level of risks according to the Agency for Toxic Substances and Disease Registry. but Anti-vaccination activists commonly cite a number of papers which claim that there is in fact a link. These are mainly published in predatory open access journals, where peer-review is virtually non-existent. Work conducted by Christopher Shaw, Christopher Exley and Lucija Tomljenovic has been funded by the anti-vaccination Dwoskin Family Foundation. The work published by Shaw et al. has been discredited by the World Health Organization.

Formaldehyde

Formaldehyde is another assumed link between vaccines and autism. Even though the assumption still circles around, formaldehyde has been used safely in the diphtheria vaccines to detoxify the bacteria used to make the vaccine. Another way it can be used is to inactivate the disease to be used in the vaccine. Formaldehyde can be found naturally in the body and environment. The human body uses formaldehyde to build amino acids and to generate the energy we need. Formaldehyde is all around us in daily life activities. It can be found in preservatives, materials used to build, and many products in homes. There is no safety concern for formaldehyde in vaccines. The most concerning repercussion is cancer after exposure to high levels of formaldehyde in the air. The amount of formaldehyde in some vaccines is less than what the body naturally produces.

Vaccine-derived measles virus Measles Virus

Measles Case Reports 1940-2007

The Centers for Disease Control and Prevention (CDC), the IOM of the United States National Academy of Sciences, and the National Health Service have all concluded that there is no link between the MMR vaccine and autism. A systematic review by the Cochrane Library concluded that there is no credible link between the MMR vaccine and autism, that the MMR vaccine has prevented diseases that still carry a heavy burden of death and complications, that the lack of confidence in the MMR vaccine has damaged public health, and that the design and reporting of safety outcomes in MMR vaccine studies are largely inadequate. Further, an epidemiology study concluded that even children labeled high risk for autism, due to an older autistic sibling, that received the MMR vaccine resulted in no causal connection between the vaccine and autism or the increased risk of being diagnosed with autism. The assumption that MMR vaccines cause autism is not isolated to the United States. A seven-year study was done in Denmark from 1991 to 1998 following children who received the MMR vaccine. The results of the study found that when comparing the vaccinated children to the unvaccinated children, the risk of autism in the vaccinated group was 0.92. Also, the risk of another autism disorder was 0.83. The study concluded there was no association between the MMR vaccine and autism. The result held even when exploring the age of the child when the vaccine was given, the vaccination date, or the amount of time after the vaccine.

Celebrity involvement Celebrities and Social Media

[edit] Some celebrities have spoken out on their views that autism is related to vaccination, including: Jenny McCarthy, Kristin Cavallari, Robert De Niro, Jim Carrey, Bill Maher, and Pete Evans.

McCarthy, one of the most outspoken celebrities on the topic, has said her son Evan's autism diagnosis was a result of the MMR vaccine. She authored Louder than Words: A Mother's Journey in Healing Autism and co-authored Healing and Preventing Autism. She also founded Generation Rescue, an organisation organization which provides resources for families affected by autism.

In a September 2015 U.S. presidential debate, Republican Party candidate and future United States President Donald Trump stated he knew of a 2-year-old child who had recently received a combined vaccine, developed a fever, and subsequently autism.

Robert F. Kennedy, Jr. is one of the most notable proponents of the anti-vaccine movement. Kennedy published the book Thimerosal: Let the Science Speak: The Evidence Supporting the Immediate Removal of Mercury--A Known Neurotoxin--From Vaccines. He is also chairman of the board of Children's Health Defense, a group and website widely known for its anti-vaccination stance.

A study conducted through Facebook explored the results of anti-vaccine ads and pro-vaccine ads. The study found that even with a similar number of anti-vaccine ads and pro-vaccine ads, the middle point in the data set of ads per buyer was higher in anti-vaccine ads. Another difference the study revealed was that the anti-vaccine ads were primarily targeted toward women and young adults who possibly had children. The pro-vaccination ads were presented evenly to different ages.

Public opinion

[edit] In December 2020, a poll of 1,115 U.S. adults found 12% of respondents believed there is evidence vaccinations cause autism; 51% believed there is no evidence; and 37% did not know.

An updated survey, conducted in March of 2023, concluded that adults think the MMR health benefits are high/very high, at 72%, and the risk of side effects is low/very low, at 64%. There has also been a drop from 2019 in United States adults who believe students in schools should be fully vaccinated. The 2023 survey showed that a decrease to 70% of U.S. adults agree that children should be vaccinated for school but an increase to 28% believe that it is the parent's right to choose if the child is vaccinated for school.

References

I added the paragraph about the Denmark study in the Vaccine-derived Measles Virus section and added the citation for it. Under the Celebrities and Social Media section, I added the study on Facebook ads, the results, and cited. Both of these updates were recommended by Asbounds in their peer review. They did suggest that I remove the first poll in the Public opinion section. I did not do this because I think it is good to show how the statistics have changed over the three-year gap between the studies.

For Pemonroe's review, I reworded, "Further, an epidemiology study concluded that even children labeled high risk for autism because of an older autistic sibling, the MMR vaccine had no causal connection to autism or the increased risk of being diagnosed with autism." I replaced "It is all around in daily life activities." with "Formaldehyde is all around us in daily activities." I did not change the updated survey paragraph in the Public opinion section. I did not change it because I did not think it was hard to read, and I am not sure how to reword it. Some feedback from you on that would be great.

I have added more information at the top of the Claimed Mechanisms section. The recommendation was given by Hannlane. She mentioned trying to explain why people believe the associations between vaccines and autism. I am worried I added too much right there, and I need to break it up. If you could give me some feedback on that portion that would be great.

I did not have a review from Fnguyen.

10/21/24

- I added images and linked the M-CHAT, formaldehyde, Agency for Toxic Substances and Disease Registry, and Children's Hospital of Philadelphia.