‘Vaccines Do Not Cause Autism’ Claim Built on ‘House of Cards,’ Authors of New Review Say

The CDC’s claim that “vaccines do not cause autism” is based on studies that don’t adequately support that claim, according to the authors of a scientific review published Jan. 10 on Preprints.org.

by Suzanne Burdick, Ph.D.

The Centers for Disease Control and Prevention’s (CDC) claim that “vaccines do not cause autism” is based on studies that don’t adequately support that claim, according to the authors of a scientific review published Jan. 10 on Preprints.org.

Brian Hooker, Ph.D., Children’s Health Defense (CHD) chief scientific officer; Jeet Varia, Ph.D., CHD science fellow; and Jeremy Hammond, an independent journalist, co-authored the report, which they plan to submit later this week for publication in a peer-reviewed journal.

Hooker told The Defender, “The truth is that CDC has never studied the connection between vaccines and autism except for one vaccine, MMR [measles-mumps-rubella], and one vaccine component, thimerosal.”

Hammond, the report’s first author, told The Defender that for the CDC’s claim that “vaccines do not cause autism” to be accurate, there would need to be studies showing that vaccines given according to the CDC’s childhood vaccine schedule cannot contribute to the development of autism in kids — including kids who may be more susceptible to developing autism because of genetic or environmental factors.

Hammond said:

“We illuminate … how the CDC’s claim is contradicted by its own cited sources. Indeed, we reveal how no studies have been done that were designed to test that hypothesis, and therefore it cannot possibly have been falsified.”

Varia agreed. “We are told time and time again that vaccines don’t cause autism. However, the bases of these assertions are made on a ‘house of cards.’”

For instance, the CDC’s “Autism and Vaccines” webpage repeatedly cites reviews by the National Academy of Medicine, formerly known as the Institute of Medicine (IoM). However, the authors say that “the IoM reviews fail to support the claim for which the CDC cites them.”

In its eighth report, the IoM’s Immunization Safety Review Committee, which examined the hypothesis that the MMR vaccine and thimerosal-containing vaccines are associated with autism, concluded that the “evidence is inadequate to accept or reject a causal relationship.”

The authors of the preprint focus their critique on a 2019 Danish study that mainstream U.S. news outlets — including CNN, NPR and The New York Times — cited as confirming that the MMR vaccine does not cause autism.

They highlight several methodological flaws in the study and a funding conflict of interest.

For instance, the Danish study authors excluded 620 children who had received a diagnosis during the first year of life for certain genetic disorders, including neurofibromatosis, tuberous sclerosis, Angelman syndrome, fragile X syndrome, Prader-Willi syndrome, Down syndrome, and DiGeorge syndrome.

The Danish study authors did not say why they excluded kids with the genetic conditions. However, the scientific review authors said the Danish study authors likely regarded the genetic disorders as “competing” with the hypothesis that MMR vaccination might increase a child’s risk of developing autism.

Instead of dropping kids with these genetic disorders from the study, the authors of the Danish study should have treated the disorders “as potential risk factors or indicators of epigenetic susceptibilities that might predispose these children to vaccine injury manifesting as symptoms of autism,” according to the scientific review authors.

The authors also criticized the Danish study for failing to control for what they called the “healthy user bias.”

“In this scenario,” they explained, “parents of children who show symptoms at an early age or who have an older MMR-vaccinated sibling with autism, developmental delays, or other chronic disease, are more likely to skip the MMR vaccine, thereby biasing correlations in favor of finding no association.”

Prior research showed found that parents whose first child was diagnosed with autism after receiving the MMR vaccine were less likely to get the shot for their second child, for fear the vaccine might contribute to the development of autism in the younger child.

Danish study marred by financial conflicts of interest

Novo Nordisk Foundation and the Danish Ministry of Health funded the 2019 Danish study.

The Novo Nordisk Foundation issues grants for scientific research while owning the holding company Novo Holdings A/S, a majority voting shareholder in the Danish pharmaceutical company Novo Nordisk.

In 2023, the Novo Nordisk Foundation invested $260 million in developing vaccines for respiratory diseases.

The authors also noted that the Danish government receives “significant” tax revenue from Novo Nordisk. They wrote, “the Danish Ministry of Health and Novo Nordisk have a vested interest in a study that might influence the demand for the MMR vaccine.”

Earlier in their report, they highlighted why that kind of vested interest is a problem:

“Researchers who faithfully serve the status quo of a vaccine orthodoxy know how to design studies to produce the desired results. …

“… When conflicts of interest influence research, the resulting scientific debate on safety and efficiency, etc., can be confounded by misleading information.”

Medical establishment needs to take parents’ concerns seriously

The scientific review authors explained how the Danish study results cannot be generalized to the CDC’s vaccination schedule.

They wrote:

“The CDC recommends 73 shots for 17 diseases, with a whopping 28 injections by a neonate’s first birthday. At a two-month ‘well-childcare visit’, an infant may receive as many as six vaccines for eight pathogens.

“In comparison, the Danish schedule consists of twelve shots for six pathogens, with only four vaccines by their first birthday (three doses each of DTaP, IPV, Hib, and PCV13).”

These “salient differences” in the number of vaccines U.S. children are advised to have versus the number of vaccines Danish health authorities recommend are commonly overlooked, they said.

Hammond told The Defender he hopes the review “contributes to the paradigm shift necessary for serious discussion to finally be had in the mainstream discourse about the many legitimate concerns that parents have about childhood vaccinations.”

The authors called for well-designed research free of conflicts of interest. Such studies should examine whether any of the vaccines on the CDC schedule — or a combination of shots, beyond just the MMR vaccine — influence a child’s risk of developing autism.

“It is past time for the medical establishment to start listening to the parents for a change and taking their legitimate concerns seriously instead of condescendingly dismissing any and all concerns about vaccination as unworthy of consideration,” Hammond said.