Check out this answer from Consensus:
The overwhelming consensus from multiple large-scale studies and meta-analyses is that there is no evidence to support the claim that vaccinating infants causes autism. Vaccines are crucial for preventing serious diseases, and the benefits far outweigh the minimal risks. Parents should feel reassured by the robust body of scientific evidence that supports the safety of vaccines.
The question of whether vaccinating infants causes autism has been a topic of significant debate and concern among parents and healthcare professionals. This article aims to review the scientific evidence available on this topic, drawing from multiple research studies to provide a comprehensive understanding of the relationship between vaccinations and autism.
Background
The controversy surrounding vaccines and autism began with a now-retracted study published in 1998, which suggested a link between the Measles, Mumps, and Rubella (MMR) vaccine and autism. Despite the retraction and subsequent studies disproving this link, the fear persists, leading to decreased vaccination rates and outbreaks of vaccine-preventable diseases.
Evidence from Meta-Analyses
A meta-analysis conducted by Taylor et al. reviewed data from five cohort studies involving 1,256,407 children and five case-control studies involving 9,920 children. The analysis found no relationship between vaccination and the development of autism or autism spectrum disorders (ASD). Specifically, the odds ratios (OR) for autism and ASD were 0.99 and 0.91, respectively, indicating no increased risk1.
Large-Scale Cohort Studies
A nationwide cohort study in Denmark involving 537,303 children also found no association between MMR vaccination and autism. The study reported a relative risk of 0.92 for autistic disorder and 0.83 for other ASD, further supporting the conclusion that MMR vaccination does not cause autism2 3.
Specific Vaccine Components
Concerns have also been raised about specific components of vaccines, such as thimerosal, a mercury-containing preservative. A study examining prenatal and infant exposure to thimerosal found no increased risk of ASD, autistic disorder, or ASD with regression. The adjusted odds ratios for these conditions were not statistically significant, indicating no association between thimerosal exposure and autism6.
Prenatal Vaccination and Autism
Another study investigated the impact of prenatal influenza vaccination on the risk of ASD in offspring. The study included 84,739 mother-child pairs and found no association between prenatal influenza vaccination or infection and ASD. The hazard ratios were 1.04 for vaccination and 1.12 for infection, neither of which were statistically significant4.
Vaccination Patterns and Autism
Research has shown that children diagnosed with ASD and their younger siblings are less likely to be fully vaccinated compared to the general population. This under-vaccination increases their risk of vaccine-preventable diseases but does not support a causal link between vaccines and autism7.
Does vaccinating infants cause Autism?
Prof Mark Pepys has answered Extremely Unlikely
An expert from University College London in Immunology
There is absolutely no single shred of evidence that vaccination, of any type, causes autism.There is also absolutely no shred of scientific evidence about either vaccination or autism suggesting any possible mechanism that could be responsible for such an association.
The whole story about MMR vaccination and autism was concocted and promulgated fraudulently, as reported in the most comprehensive, in depth, precisely detailed and documented investigation by Brian Deer, an eminent, prize winning journalist (http://briandeer.com/mmr-lancet.htm). Unfortunately the impact was greatly magnified and perpetuated by the egregious conduct of the formerly reputable British medical publication, The Lancet, which behaved disgracefully badly in this matter. Also, very sadly, the regrettable conflation of association and causality, led many otherwise well-meaning non-scientific and non-medical people in the general population, to accept the false connection and to promote it. This happened despite the irrefutable fact that the purported association between vaccination and autism did not and does not exist, let alone any causal relationship between them.
Most tragically, the reduction in uptake of MMR vaccination resulting from the Wakefield scandal has directly caused the well documented sickness, maiming and death of thousands of children from measles, and continues to do so up to the present. Outbreaks of measles causing severe illness and some deaths continue to occur in the developed world while, catastrophically, in the developing world the lethal consequences of insufficient MMR vaccination are even more severe.
Does vaccinating infants cause Autism?
Richard Zimmerman has answered Extremely Unlikely
An expert from University of Pittsburgh in Vaccinology, Epidemiology
I have an autistic child. Thus, understanding the causes of autism and preventing other children from contacting autism is important to me.
I have reviewed the scientific evidence about vaccines and autism and reject any association between the two. One of those who proclaims such an association is Andrew Wakefield whose work has been discredited in mainstream medical and scientific circles and who is reported to have received funding from litigants.
The preservative thimerosal contains mercury and some are concerned that it caused autism. There are no confirmed data to support this allegation. Out of caution, thimerosal has been removed from US childhood vaccines (only multidose vials of influenza vaccine have it as a preservative; single dose syringes do not have thimerosal). Yet, the rates of autism have risen in the US after the thimerosal was removed, further supporting the safety of the vaccines; something else must be causing autism if children are getting it despite thimerosal’s removal.
My child’s autism was not caused by vaccines and I have my family vaccinated.
Does vaccinating infants cause Autism?
Michael Fitzpatrick GP has answered Extremely Unlikely
An expert from Barton House Health Centre in Medicine
MMR does not cause autism.
There are four links in the proposed chain of causality connecting MMR to autism:
- MMR immunisation leads to chronic measles infection (and immune dysfunction). The MMR vaccine contains an ‘attenuated’ strain of the measles virus which has been specially developed to diminish its capacity to cause disease, while conserving its capacity to provoke an antibody reaction that will protect against further exposure to the wild measles virus. (The fact that, though attenuated, this is still a live virus means that MMR has NEVER contained thimerosal or any form of mercury, which would render it inactive.) By contrast with the wild measles virus, the attenuated strain reproduces sluggishly, does not cause disease and provokes a much lower immune response. MMR has never been shown to cause either measles or immune dysfunction.
- ‘Autistic enterocolitis’ or ‘new-variant inflammatory bowel disease’ results from measles infection. In the 20 years since his (now discredited and withdrawn) Lancet paper suggested that MMR caused bowel inflammation, neither Andrew Wakefield nor any of his supporters has produced evidence that has been accepted as supporting his hypothesis.
- A ‘leaky bowel’ resulting from ‘autistic enterocolitis’ allows toxic opioid peptides to enter the blood stream. Wakefield and his collaborators have also failed to demonstrate the existence of either increased gut permeability or toxic peptides following MMR. Children who suffer from inflammatory bowel disease or immune deficiency states do not have increased rates of autism.
- ‘Opioid excess’ causes ‘regressive’ or ‘atypical’ autism. Neither the existence of toxic opioids nor the mechanism by which they might cause autism has been substantiated. This theory is inconsistent with the widely accepted contribution of genetic factors to the development of autism. Large scale epidemiological studies conducted in different countries have failed to reveal any link between MMR and any form of autism.
Does vaccinating infants cause Autism?
Dwight German has answered Extremely Unlikely
An expert from UT Southwestern Medical Center in Neuroscience
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in communication (verbal and nonverbal), social interactions, and stereotyped behaviors/interests. The etiology of ASD is not well understood, though it involves both genetic and environmental factors. Immune system dysfunction has been reported in many ASD studies. Systemic immunologic alterations in ASD individuals often have been associated with autoimmunity; in particular, the generation of antibodies reactive against brain and CNS proteins. ASD symptoms become apparent during the time period when children are given vaccinations, leading some people to think that the vaccines and/or the mercury preservative (thimerosal) play a role in symptom onset. We recently studied the brains and behavior of non-human primates, exposed to the same human childhood vaccination schedules to determine whether neurodevelopmental changes occur. This work was done in collaboration with the National Primate Research Center at the University of Washington Medical School. We found that the vaccines/thimerosal caused no behavioral or brain abnormalities that are characteristic of ASD. Please read more about the study here: http://www.pnas.org/content/112/40/12498
Does vaccinating infants cause Autism?
David M Ojcius has answered Extremely Unlikely
An expert from University of the Pacific School of Dentistry in Immunology, Cell Biology, Microbiology
The claim that there is a link between MMR vaccines and autism was extensively studied and found to be false.
Does vaccinating infants cause Autism?
Amelia Warren has answered Extremely Unlikely
An expert from Bond University in Behavioural Science, Neuropsychology
Vaccination, particularly the administration of Measles/Mumps/Rubella (MMR) vaccines, has been implicated in the aetiology of autism spectrum disorder (ASD) for three primary reasons: (1) the administration of the measles, mumps, and rubella vaccines simultaneously may damage the lining of the intestine permitting potential brain-damaging proteins into the intestine (Wakefield, 1998), (2) the immune system may not be able to manage the multiple vaccine in one, causing it to weaken and fail (Gerber & Offit, 2009), and (3) MMR contains elevated doses of thimerosal, which when metabolised forms an organic-mercury toxic to the nervous system (Dorea, Farina, & Rocha, 2013). The initial hypothesis was presented by Wakefield et al. in 1998 who found eight participants displayed autistic symptoms less than a month after being vaccinated. Additionally, they all presented with gastrointestinal issues. This led to the conclusion MMR caused intestinal inflammation allowing the entrance of nonpermeable peptides into the bloodstream and altering brain development. This hypothesis was congruent with public opinion who understood symptom occurrence for autism occurred around the same time of MMR administration, leading to the causal connection between the MMR vaccine and autism development. However, it has been discredited for several reasons including: (1) small sample size, (2) lack of control subjects, (3) incomplete and biases data collection, (4) the viruses caused by MMR vaccines have not been found to significantly overwhelm the immune system, (5) potential brain-damaging nonpermeable peptides have not been identified, and (6) the gastrointestinal symptoms did not occur prior to ASD symptoms in some children. Moreover, a myriad of subsequent studies with sound methodology (including ecological, case-control double-blind, retrospective cohort, and prospective cohort studies) failed to show any association between MMR and ASD (Gerber & Offit, 2009). The level of thimerosal hypothesis may have credence due to the known toxicity of the related toxin methylmercury, which is considered a toxic substance even in the low doses found in seafood (Dorea et al., 2013). When comparing the toxicity of methylmercury and ethylmercury (the thimerosal metabolite), it was found in vitro studies revealed similar toxicokinetic profiles on cell destruction, whereas in vivo studies indicate that ethylmercury has a shorter proliferation in the bloodstream and is more readily eliminated that methylmercury (Dorea et al., 2013). This suggests that although these compounds are not favourable in even low doses, the risk of toxicity is higher in methylmercury. Both are not favourable for child development, but in perspective, the amount of organic mercury found in a single serving of tuna (e.g., one can) is equivalent to the amount found in a single vaccination shot (Oken & Bellinger, 2008). This notwithstanding, it may be that the multiple vaccinations simultaneously early in infancy (before 6 months) are sufficiently bio-accumulative to result in neurologic abnormalities often associated with ASD. Other symptoms that correlate with ASD but are not necessary for a diagnosis (e.g., gastrointestinal issues) may also be sensitive to the immune weakening resultant of the three-virus injection. ASD is an extremely heterogenous neurodevelopmental disorder characterised by socialisation and communication impairments, as well as rigid and repetitive behaviours (APA, 2013). The heterogeneity of these symptoms manifesting has led to the development of multiple aetiological explanations. Moreover, the high heritability of ASD (estimates range from 60-90%) have largely ruled out vaccines as a cause for autism. There is evidence to suggest numerous factors that contribute to ASD development, such as genetics (Badcock & Crespi, 2006), epigenetics (Hall & Kelly, 2014), neurotransmitter dysfunction (Tansey et al., 2010), gastrointestinal problems (Cubala-Kucharska, 2010), vitamin deficiencies (Cannell, 2010), and in-utero (Baron-Cohen et al., 2011) and environmental influences (Hallmeyer et al., 2011). Vaccines may contribute to these factors, but much of the evidence suggests that vaccines are not sufficient to cause autism. This notwithstanding, as a practitioner as well as a researcher, I have heard to the pain of parents who live under the guilt of believing a vaccination caused ASD in their child, who was developing normally prior to their vaccination. This has been both heartbreaking and compelling, and the account of development from the parent’s perspective should not be discounted. More research need be undertaken into vaccine ramifications, particularly given the recent social movements against vaccinations aided by documentaries like Vaxxed and the political figures such as Donald Trump and Pauline Hanson.
Does vaccinating infants cause Autism?
David Hawkes has answered Extremely Unlikely
An expert from University of Melbourne in Virology, Gynaecology
Vaccination does not cause autism.
There are a wealth of long term, higher quality, large cohort studies that demonstrate this. Additionally there is not biological mechanism by which vaccination could cause autism or autism spectrum disorders.
I response to the other ‘expert’ Ms Warren presents three arguments which appear to infer that there is some basis for vaccination to be causationaly associated with vaccination;
- the administration of the measles, mumps, and rubella vaccines simultaneously may damage the lining of the intestine permitting potential brain-damaging proteins into the intestine (Wakefield, 1998)- A paper retracted for reasons stated as “Following the judgment of the UK General Medical Council’s Fitness to Practise Panel on Jan 28, 2010, it has become clear that several elements of the 1998 paper by Wakefield et al1 are incorrect, contrary to the findings of an earlier investigation.
- In particular, the claims in the original paper that children were “consecutively referred” and that investigations were “approved” by the local ethics committee have been proven to be false. Therefore we fully retract this paper from the published record.” There have been several large scale (>500,000 children) studies including https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1173183/ 2. the immune system may not be able to manage the multiple vaccine in one, causing it to weaken and fail (Gerber & Offit, 2009). If this was correct then we would observe immunocompromised children following vaccination – which is not the case. In fact the vaccine schedule given to children in 2017 has less antigens than the schedule given to children in 1977, mostly due to the substitution of the whole cell pertussis vaccine with the acellular version.
- MMR contains elevated doses of thimerosal, which when metabolised forms an organic-mercury toxic to the nervous system (Dorea, Farina, & Rocha, 2013). The problem with this claim is that MMR, and all vaccines in Australia and many countries internationally, had thimerosal removed in 2000 – since then we have seen an increase in autism spectrum disorder (ASD) which most experts attribute to the change in diagnostic criteria and an awareness, and social acceptability of an ASD diagnosis over other developmental conditions such as ‘mental retardation’. It is also worth noting that mercury poisoning is a recognized condition (http://emedicine.medscape.com/article/1175560-differential ), but one that has little in common with ASD (https://www.cdc.gov/ncbddd/autism/signs.html ). There is also no evidence that MMR ‘weakens the immune system’ as Ms Warren claims. We know what a weakened immune system looks like as there are a wide range of immunocompromised people for a range of reasons – none of which are vaccination. Ms Warren’s claim that ‘Vaccines may contribute to these factors, but much of the evidence suggests that vaccines are not sufficient to cause autism’ is simply incorrect. The factors she suggests are: genetics, epigenetics, neurotransmitter dysfunction, gastrointestinal problems, vitamin deficiencies , and in-utero and environmental influences. How exactly does she propose that vaccination alters the genetic make up of children? or how does vaccination cause vitamin deficiencies? What is the evidence that vaccination , particularly MMR, is associated with epigenetic changes, neurotransmitter dysfunction, in-utero influences or even environmental influences? The (often professional) anti-vaccination movement is responsible for putting so much additional stress on parents by making them feel guilty for their childs condition. There is no evidence that vaccination is associated with autism/ASD. As someone who claims to be an expert surely Ms Warren could help educate these parents that their decision to vaccinate their child and therefore protect them from a range of diseases that kill and main hundreds of thousands of children a year, played no role in their child having autism/ASD.
In terms of social movements, Pauline Hanson and Donald Trump do not have any research experience, education or any other professional experience which would make their views on the subject informed. As for Vaxxed, it was made by a range of people who are professional anti-vaccinationists – for many of the people associated with the film included Andrew Wakefield and Polly Tommey who runs (and appears to earn income) a charity called the Autism Trust which has been roundly criticised by those in the autism community in the UK. Whilst there could certainly be a case made for improving communication to vaccine hesitant parents, that doesn’t detract from a massive body of work which shows that vaccination is not associated with autism.
Does vaccinating infants cause Autism?
Gabriela Segal has answered Extremely Unlikely
An expert from University of Melbourne in Immunology, Microbiology, Microscopy, Cancer
This is absolutely untrue there is no scientific evidence for this claim except for this one retracted paper. There has been plenty more studies proving there is no correlation between autism and vaccinations.
Does vaccinating infants cause Autism?
Jerry Tsang has answered Extremely Unlikely
An expert from Edinburgh University in Medicine, Biological Materials, Anatomy, Microbiology
The link between vaccinations and autism was first proposed in 1998 by Andrew Wakefield. The study on which his claims were based on has now been retracted following a GMC fitness to practise review of Dr Wakefield in 2010. One of the many concerns that the GMC had was the failure of Dr Wakefield to declare that he and several of the children in the study were involved in a lawsuit attempting to show that MMR was linked to autism.
Further larger studies investigating this potential relationship have found no evidence to support Dr Wakefield’s claims (Taylor et al 1999 and Dales et al 2001)
Does vaccinating infants cause Autism?
Paul Ernsberger has answered Extremely Unlikely
An expert from Case Western Reserve University in Pharmacology, Nutrition, Cardiology, Nephrology, Endocrinology, Obesity
The lack of adverse effects of vaccines has been proven in numerous trials.
Does vaccinating infants cause Autism?
John Molinari has answered Extremely Unlikely
An expert from University of Detroit Mercy in Immunology, Dentistry
Multiple long term clinical studies have been conducted and published in peer reviewed journals showing vaccines do not cause autism. The 2011 Institute of Medicine report entitled “Adverse Effects of Vaccines: Evidence and Causality” reaffirmed this conclusion after reviewing and analyzing the scientific evidence. In addition to stating that there are relatively few health problems associated with commonly recommended vaccines, the report also concluded that there was no evidence to support a connection between the MMR vaccine and autism. This erroneous claim was first made by a British physician in the late 1990’s in an article later shown to be fraudulent.
Does vaccinating infants cause Autism?
Franca Ronchese has answered Extremely Unlikely
An expert from Malaghan Institute of Medical Research in Immunology
There is no evidence, from any study, that infant vaccination causes autism. The answer to this question is “No”.