What Causes Autism?

This infographic presents some of what we know about immune activation events causing autism and states the vaccine-autism hypothesis.

Given the close association between the immune system activations and autism, supported by animal testing, the vaccine-autism hypothesis is highly plausible.

After all, the purpose of vaccines is to activate the immune system, which is something we know can trigger autism.

Sources are listed and linked below, and I have copied a line from the abstract of each study for the convenience of the reader.


  1. Hallmeyer, 2015: Autism heritability was estimated to be 38% and the shared environmental component to be 58% https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4440679/
  2. Atladottir, 2010: admission to hospital due to maternal viral infection in the first trimester and maternal bacterial infection in the second trimester were found to be associated with diagnosis of ASDs in the offspring https://www.ncbi.nlm.nih.gov/pubmed/20414802
  3. Zerbo, 2015: women with infections diagnosed during a hospital admission, particularly bacterial infections, were at increased risk of delivering a child with ASD https://europepmc.org/articles/pmc4108569
  4. Vargas, 2005: The brains of people with ASD show a marked activation of microglia and astroglia, and cytokine profiling indicated that MCP-1 and TGF- β1, derived from neuroglia, were the most prevalent cytokines. Cerebrospinal fluid showed a unique proinflammatory profile of cytokines, including a marked increase in MCP-1. https://www.ncbi.nlm.nih.gov/pubmed/15546155
  5. Li, 2015: Neonatal vaccination of rats with bacillus Calmette-Guérin and hepatitis B vaccines modulates hippocampal synaptic plasticity https://www.ncbi.nlm.nih.gov/pubmed/26531688
  6. Wei, 2011: The cerebellum of the brains of people with ASD has increased IL-6, which alters neural cell adhesion, migration and synaptic formation https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3114764/
  7. Abdallah, 2013: The amniotic fluid of mothers of children with ASD showed elevated levels of inflammatory cytokines https://www.ncbi.nlm.nih.gov/pubmed/22175527
  8. Suzuki, 2013: In multiple brain regions in people with ASD there is excessive microglial activation https://www.ncbi.nlm.nih.gov/pubmed/23404112
  9. Jones, 2017: The serum of mothers of children with ASD with ID showed increased levels of maternal cytokines and chemokines during gestation https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5122473/
  10. Tsilioni, 2019: The brains of children with ASD have increase inflammatory cytokines https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6027314/
  11. Smith, 2007: Maternal immune activation (MIA) in mice alters fetal brain development through interleukin-6 https://www.ncbi.nlm.nih.gov/pubmed/17913903
  12. Malkova, 2012: MIA in mice results in offspring that show more autism-like behaviours https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3322300/
  13. Bauman, 2014: MIA in rhesus monkeys yields offspring with abnormal repetitive behaviors, communication, and social interactionshttps://www.ncbi.nlm.nih.gov/pubmed/24011823
  14. Choi, 2016: Either MIA or direct administration to the fetal brain of mice of inflammatory cytokine IL-17a promotes abnormal cortical development and ASD-like behaviors in offspring https://www.ncbi.nlm.nih.gov/pubmed/26822608
  15. Missig, 2018: Early-life immune activation in mice can lead to long-lasting physiologic perturbations that resemble medical comorbidities often seen in ASD and other neuropsychiatric conditions https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5770773/

MMR-Autism Association in DeStefano 2004 Study

William Thompson is the CDC whistleblower who revealed that he had been involved in a cover-up of a key result in the vaccine-autism debate.

He was referring to the DeStefano 2004 study of MMR and autism, on which Thompson was a co-author, conducting the statistical analysis. Thompson claimed that an association between MMR and autism in African American boys was identified in the data, but that the finding was omitted from the final paper. He cited the pressure to show no association between MMR and autism, and explained how they tried various statistical techniques to try to hide the association.

The infographic above presents the data behind the debate. Brian Hooker’s 2014 re-analysis of the data shows there is indeed an association between MMR and autism in African American boys in the data.

Forget the politics; the science here is telling us there is an association between a vaccine and autism.


Vaccine Autism Studies Inadequate

In 2012, the Institute of Medicine (IOM) released a comprehensive evidence review entitled “Adverse Effects of Vaccines: Evidence and Causality”.

They looked at 8 different vaccines and 76 different adverse events. One of these adverse events was autism.

  • For 1 vaccine (MMR), the IOM favored rejection of a causal relationship.
  • For 1 vaccine (DTaP), the IOM declared the evidence inadequate to accept or reject a causal relationship.
  • For the other 6 vaccines in the review, the IOM did not look for any evidence regarding a causal relationship.

Clearly then, the correct conclusion of this evidence is NOT that “vaccines do not cause autism”. There is not enough evidence to make that conclusion.

Even if a causal relationship between MMR and autism is rejected, it does not follow that “vaccine do not cause autism” because MMR is only one of 8 or more vaccines, and the evidence is inadequate to accept or reject a causal relationship for them. There have also been no studies looking for associations between cumulative vaccinations, or different timings, or different combinations of vaccines, and autism.

The CDC cites this IOM report for its claim that “vaccines do not cause autism” and yet this report does not support this claim.

Maternal Immune Activation and Autism

The diagram in the infographic above comes from:

The CDC Vaccine-Autism Studies

The studies cited by the CDC on their “Vaccine Do Not Cause Autism” page cannot possibly support that claim. The CDC’s conclusion is invalid.

See the infographic above for details about why that is.

The Vaccine-Autism Hypothesis

Here are the sources for each point in the above infographic.

Genetic / Environmental Etiology

The Claim: Autism is partly but not wholly genetic; it can be triggered in genetically susceptible individuals by environmental factors that alter neurodevelopment

The Sources:

Infections in Pregnancy

The Claim: A wide range of bacterial and viral infections during pregnancy are associated with autism, so one trigger is a serious immune activation event during a critical stage of neurodevelopment

The Sources:

  • Atladottir, 2010: admission to hospital due to maternal viral infection in the first trimester and maternal bacterial infection in the second trimester were found to be associated with diagnosis of ASDs in the offspring  https://www.ncbi.nlm.nih.gov/pubmed/20414802
  • Zerbo, 2015: women with infections diagnosed during a hospital admission, particularly bacterial infections, were at increased risk of delivering a child with ASD  https://europepmc.org/articles/pmc4108569

Immune Activations in Animals

The Claim: Immune activations in pregnant or newborn animals alter neurodevelopment and increase autistic-like behaviors in the pups and infants; multiple immune challenges multiply the effect.

The Sources:

Inflammation and Autism

The Claim: Inflammation is an immune system response to a challenge.  Inflammation is associated with autism.

The Sources:

Vaccines and Immune Activation

The Quote: “Immune activation is the objective of vaccines”

… is from Matheson vs. Schmitt, Plotkin Deposition, 16:27:56, 11 Jan 2018  https://www.cafepeyote.com/files/Plotkin_Deposition_-_Summary.pdf or https://youtu.be/DFTsd042M3o?t=24959

Here is the context of the quote:

  • QUESTION: Are you familiar with the study called “Maternal Immune Activation Alters Fetal Brain Development through Interleukin-6” [Smith, 2007]?
  • PLOTKIN: Vaguely, yes. Yeah.
  • QUESTION: Published in the Journal of Neuroscience?
  • PLOTKIN: Yeah, well, I don’t remember the journal.
  • QUESTION: Is that one of the journals you consider respectable?
  • PLOTKIN: Yes.
  • QUESTION: And this was out of the University of California Medical Center. This is from California Institute, CalTech. That institution did a number of studies regarding — that group did a number of studies relating to immune activation and neurological disorder, correct?
  • PLOTKIN: Yes.
  • QUESTION: And they found a connection between immune activation and neurological historical disorders, correct?
  • PLOTKIN: Yes.
  • QUESTION: Okay. And one of the study’s findings they had was that immune activation alters fetal brain development through interleukin-6, correct?
  • PLOTKIN: As I said before, IL-6 is an important cytokine. I would point out in relation to immune activation, that immune activation occurs as a result of disease and exposure to a variety of stimuli, not just vaccines.
  • QUESTION: But it can be caused by vaccines, correct?
  • PLOTKIN: Immune activation is the objective of vaccines.

The Claim: Challenges to the immune system can come from wild pathogens or from vaccines

This is confirmed by the quote above from Plotkin, as well as any immunology textbook.

The Claim: Vaccines must activate the immune system strongly in order to work

The Claim: Aluminum adjuvants are used in many vaccines specifically to increase the challenge to the immune system and boost the response

These two claims are basic to how vaccines work, as explained on the websites of the CDC and the CHOP:

 “An adjuvant is an ingredient used in some vaccines that helps create a stronger immune response in people receiving the vaccine. In other words, adjuvants help vaccines work better. Some vaccines that are made from weakened or killed germs contain naturally occurring adjuvants and help the body produce a strong protective immune response. However, most vaccines developed today include just small components of germs, such as their proteins, rather than the entire virus or bacteria. Adjuvants help the body to produce an immune response strong enough to protect the person from the disease he or she is being vaccinated against. Adjuvanted vaccines can cause more local reactions (such as redness, swelling, and pain at the injection site) and more systemic reactions (such as fever, chills and body aches) than non-adjuvanted vaccines.”

CDC https://www.cdc.gov/vaccinesafety/concerns/adjuvants.html

 “Aluminum is used in vaccines as an adjuvant. An adjuvant is a vaccine component that boosts the immune response to the vaccine. Adjuvants allow for lesser quantities of the vaccine and fewer doses. The adjuvant effects of aluminum were discovered in 1926. Aluminum adjuvants are used in vaccines such as hepatitis A, hepatitis B, diphtheria-tetanus-containing vaccines, Haemophilus influenzae type b, and pneumococcal vaccines, but they are not used in the live, viral vaccines, such as measles, mumps, rubella, varicella and rotavirus.”

CHOP https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-ingredients/aluminum

Unlock the VSD Goldmine

The Institute of Medicine (IOM) systematic review entitled “The Childhood Immunization Schedule and Safety: Stakeholder Concerns, Scientific Evidence, and Future Studies (2013)” confirmed there had been no studies of the vaccine schedule, and it called for such studies to be done.

It then tells us the most feasible way to carry out these urgently-needed studies:

The most feasible approach to studying the safety of the childhood immunization schedule is through analyses of data obtained by VSD. VSD is a collaborative effort between CDC and 9 managed care organizations that maintain a large database of linked data for monitoring immunization safety and studying potential rare and serious adverse events. VSD member sites include data for more than 9 million children and adults receiving vaccinations on a variety of immunization schedules.

The VSD (Vaccine Safety Datalink) is potentially a goldmine of data that could be decisive in the vaccine science debates, but the CDC keeps it locked up. It makes the data available only to select individuals; it is not publicly available for independent researchers to analyse.

Making anonymised VSD data available to everyone would be an easy and cheap way to enable epidemiological studies of all different vaccine schedules to be carried by anyone who has doubts about vaccine safety or efficacy and wants to verify the raw data.

Why doesn’t the CDC want independent researchers or parents to be able to compare health outcomes between populations vaccinated on different schedules or unvaccinated?


The Vaccine Schedule has Not Been Tested

The vaccine schedule has not been tested.

This is according to the Institute of Medicine (IOM) systematic review entitled “The Childhood Immunization Schedule and Safety: Stakeholder Concerns, Scientific Evidence, and Future Studies (2013)”, a report which is cited by the CDC.

Here is the full quote:

In summary, few studies have comprehensively assessed the association between the entire immunization schedule or variations in the overall schedule and categories of health outcomes, and no study has directly examined health outcomes and stakeholder concerns in precisely the way that the committee was charged to address in its statement of task. No studies have compared the differences in health outcomes that some stakeholders questioned between entirely unimmunized populations of children and fully immunized children. Experts who addressed the committee pointed not to a body of evidence that had been overlooked but rather to the fact that existing research has not been designed to test the entire immunization schedule.

Vaccines have been tested, but the vaccine schedule has not been.

A test of the vaccine schedule would entail comparing health outcomes between populations given different combinations of vaccines, including fully unvaccinated, selectively vaccinated, and fully vaccinated according to the recommended schedule (which is different in different countries). As the IOM quote above makes clear, there are no such studies.

Retrospective cohort and case-control studies comparing health outcomes between populations vaccinated using different schedules are urgently needed.


Aluminum from Vaccines and Diet

Let’s calculate how much aluminum babies are exposed to from each of the three main sources of aluminum exposure – diet, the air, and vaccines – in their first year.

Breast milk contains about 40mcg/L of aluminum [Keith, 2002].  Newborn babies drink an average of 0.5L/day, increasing over the first 30 days up to an average of 0.75L/day, which continues until they start replacing milk with solid foods [KellyMom].  A fully breastfed baby will therefore ingest 10.8mg of aluminum in breast milk over the first year.  Formula contains about 225mcg/L of aluminum [Keith, 2002]; by the same calculation, a baby will ingest 60.8mg of aluminum from formula in the first year.  About 0.78% of ingested aluminum lactate is absorbed through the gut into the bloodstream [Mitkus, 2011], for a total aluminum uptake of 84mcg from breast milk or 475mcg from formula.

We are also exposed to aluminum in the air we breathe; about 0.86 mcg/kg/day of aluminum enters our lungs [Krewski, 2007].  For an average weight newborn, that is 2.8mcg/day, increasing to 8.3mcg/day by the end of the year, for a total aluminum intake of 2.2mg for the first year.  About 2% is absorbed through the lungs into the bloodstream, for a total uptake of aluminium through the lungs of 44mcg for the year.

An unvaccinated baby will therefore absorb between 128mcg (breast milk) and 518mcg (formula) of aluminum into the bloodstream in the first year.  Most of this will be eliminated by functioning kidneys; the rest will accumulate in the bones and soft tissues.

Based on the 2011 ACIP vaccination schedule, the total amount of aluminum in all the vaccines given in the first year of life is 3,635mcg [Mitkus, 2011]; most is in the form of aluminum hydroxide, and the rest is in the form of aluminum phosphate. 

After being injected intra-muscularly, the aluminum slowly gets absorbed into the bloodstream; aluminum hydroxide is believed to be fully absorbed after 166 days and aluminum phosphate after 56 days [Flarend, 1997].  The latest vaccine in the first-year schedule is given at 6 months, so by the end of the first year all the aluminum from all the vaccines has had time to be fully absorbed, so 3,635mcg of aluminum from vaccines enters the bloodstream in the first year.

The total intake and uptake of aluminum, and the percentages from each source, are shown in the tables below.

Vaccines are the major source of aluminum exposure in the first year: between 87% and 97% of the aluminum absorbed into the bloodstream comes from vaccines, with only a very small proportion from the diet and air.  If breast-fed, the amount of aluminum absorbed from vaccines is 40x more than the amount absorbed from diet and air; if formula-fed, it is 5x more. 

As a result of the increased exposure to aluminum, the accumulation of aluminum in the bones and soft tissues will be far higher in a vaccinated baby than in an unvaccinated baby.


How We Conquered Measles

In 1915, in England & Wales, there were 16,455 deaths from the measles; 70% of measles deaths were children aged 1-4. Measles was the biggest killer of toddlers, responsible for 20% of all toddler deaths.  It was also the 2nd biggest killer (behind diphtheria) of children aged 5-9. Although 1915 was a peak year, the average at the time was around 10k total measles deaths per year. 

In 1994, there were no measles deaths at all. From then until now, there have been few years where we have had more than one measles death.

How did we achieve this? How did we conquer measles? 

The answer can be found in this chart that shows the number of measles deaths (black) between 1901 and 2016, and the number of measles notifications (red) between 1940 and 2016.

1915 to 1955: Dramatic Reduction in CFR

From 1915 to 1955, measles deaths reduced by 99%, from over 10,000 deaths per year to below 100 deaths per year.

Most of the decline happened between 1915 and 1935.  In 1935, there were only 1,346 deaths from measles, a reduction of 92% over a 20-year period.  The measles death rate fell even faster than the overall infant mortality rate; it was now responsible for only 7% of deaths of children aged 1-4 (now only the 3rd biggest killer), and only 2% of deaths of children aged 5-9 (now only the 10th biggest killer).  

In 1955, there were only 176 deaths from measles, a reduction of 99% over a 40-year period.  In most years of the 1960s, there were fewer than 100 measles deaths per year, and measles was no longer among the top 10 killers of children of any age group. Measles was now responsible for only 3% of deaths of children aged 1-4 (the 7th biggest killer) and 2% of deaths of children aged 5-9 (the 9th biggest killer). 

Turning now to measles notifications, for which we have data only back to 1940, we can see that the number of notifications of measles was flat from 1940 to 1968 (the pre-vaccine period), at around 400k on average. The driver behind the dramatic decrease in the number of deaths was therefore a dramatic reduction to the Case Fatality Rate (CFR), i.e. the number of deaths per case (or the inverse of the survival rate). Just as many children caught measles, but far fewer died from it.

We can use notifications as a proxy for cases to calculate the CFR for the period after 1940. To estimate the CFR for the period 1901-1940 we need to use birth numbers, as in the following chart:

By assuming a similar proportion of children caught the measles before 1940 as in 1940-68 (i.e. most of them), we can extrapolate the CFR backwards, giving us the following chart:

The CFR prior to 1915 was over 2%, meaning that 1-in-50 children who caught measles died from it. By 1940, it had decreased to 0.2% (1-in-500), and by 1955 it had decreased to just 0.02% (1-in-5000). This is a 99% reduction in the CFR. This reduction in the CFR is why measles was no longer considered a serious, life-threatening illness during the period 1955 to 1968; 99.98% of children survived it. The average number of measles deaths per year was down to below 100 by 1955.

1955 to 1968: CFR Stops Decreasing

In 1955 the incredible reduction in the CFR suddenly stopped. It remains at around 0.02% even today, as can be seen in this chart:

Let us now re-scale the deaths axis of our first chart to see what this meant for the deaths figures after 1955:

As a result of the flat CFR, the number of deaths stayed at just below 100 per year for the period 1955-1968. The record lowest numbers of measles deaths in the pre-vaccine era were in 1956 (30 deaths), 1960 (31 deaths), 1962 (39 deaths). The most deaths in this period were in 1961 (152 deaths), 1963 (127 deaths), and 1965 (115 deaths) and no other years in this period had more than 100 deaths.

1968 to 1997: Vaccines Reduce Measles Cases

From 1968 to 1997 there was a 99% reduction in measles cases. The majority of that reduction followed the introductions of the measles vaccine (1968) and the MMR vaccine (1988). From 1968 to 1971, the annual number of measles notifications fell by over 60%, from 400k to 150k. From 1988 to 1991, notifications fell by 90%, from 100k to 10k. With a flat CFR, the 99% reduction in cases from 1968 to 1997 meant a 99% reduction in deaths, from 100 per year before vaccines down to just 1 per year.

1997 to present: Measles Now Rare

In most years since 1997, there have been under 5k cases and rarely more than 1 death, as we can see by one final re-scaling of the chart:

How then did we conquer measles?

Measles killed over 10,000 per year before 1915 but fewer than 100 per year by 1955.  This 99% reduction in measles deaths was due to a dramatic reduction in the deadliness of the disease between 1915 and 1955.  This could have been due to a healthier environment (higher standards of hygiene, better sanitation systems, more nutritious food, cleaner drinking water and air, less cramped living and working conditions, etc) or to better treatment of measles cases (improved medical knowledge among doctors and the public, better access to healthcare, more effective quarantine procedures, etc), or both. 

The healthier environment and better quality treatments deserve credit for making measles a relatively mild disease; these developments saved thousands of lives each year, just in England & Wales. The measles and MMR vaccines reduced the number of measles cases and measles deaths by another 99%, saving dozens more lives per year. Vaccines deserve credit for making it rare for anyone to suffer from the measles.