Refuting Misinformation Regarding the Use of Fetal Cell Tissues for Vaccine Manufacturing

Recently, the Archdiocese of Seattle removed all religious, philosophical and personal exemptions to vaccination requirements at the catholic schools they oversee. This triggered a response from a local anti-vaccine group that included a protest at the archdiocese’s headquarters. Here’s the coverage from the local news:

At one minute and fourteen seconds in the report, an activist declares that there is medical evidence that “injection with fetal DNA fragments can cause insertional mutagenesis, tumors, autoimmune disease…” There is no medical evidence to this. The only evidence available is the continued statements, testimonies and open letters by Theresa Deisher, PhD. Dr. Deisher has been very active in arguing against vaccination in different settings. For example, she testified via an open letter to Connecticut legislators about vaccines.

A version of that open letter was then published in Vaccine Impact, a website that publishes such headlines as “Medical Kidnap Show to Expose Corruption in Arizona Regarding Child Sex Trafficking Thursday October 10th” and imagery such as this:

Screenshot 2019-10-12 10.57.36
There is no evidence that there is a causal association between vaccination and higher infant mortality rates. Quite the opposite.

We are not providing a link to the site at this time, but one can easily find it via Google and in the review linked below.

Recently, a group of three scientists reviewed the claims made by Dr. Deisher. They found her claims to be “unsupported and implausible”.  Here is the summary of their findings:

“This article by Vaccine Impact, published on 19 May 2019 and shared more than 13,000 times, reproduces an open letter written by Dr. Theresa Deisher to legislators about the purported dangers of fetal DNA in vaccines produced with fetal-derived cell lines. The letter claims to discuss “unrefuted scientific facts about fetal DNA contaminants in the MMR vaccine”, founded in large part on a study co-authored by Dr. Deisher herself[1].

Immunologists who reviewed the open letter found its claims to be unsupported and implausible. They acknowledged that certain vaccines are produced using human fetal-derived cell lines, but pointed out that the study of Deisher et al. does not actually demonstrate that fetal DNA is present in vaccines, let alone in a high concentration, having methodological problems that call into question its findings.

While the letter provides a reference list that appears to lend support to its claims, a closer examination shows that the citations are not used appropriately, being misinterpreted or taken out of context.

Nevertheless, the letter maintains the assumption that high levels of fetal DNA are present in vaccines, coupling it with the fact that Toll-like Receptor (TLR) 9 activates a proinflammatory response upon sensing DNA to claim that fetal DNA in vaccines causes autoimmunity. While it is true that TLR9 is involved in autoimmune diseases, reviewers also explain that TLR9 senses only unmethylated DNA (like that of bacteria and viruses), whereas human DNA would be methylated. This means that even if fetal DNA was present – which was not even proven by Deisher et al. to begin with – it would not be able to activate TLR9 anyway.

They also point out that it is implausible for homologous recombination of fetal DNA after vaccination to cause autoimmunity and autism, since it necessitates a chain of events that are extremely unlikely to happen all together, especially in the biological context of a living person and not the artificial environment of a test tube. Another problem with the claim of insertational mutagenesis is the fact that pregnant women, who have higher levels of circulating fetal DNA constantly over 9 months, do not have a higher incidence of cancer. It is therefore unlikely that mutagenesis would occur in children after vaccination – an event that is spread out over several periods – with much lower amounts of fetal cell line-derived DNA.”

Basically, if it was that easy for fetal DNA to get into our DNA through vaccination and cause some sort of change, gene therapy would be effortless. It is not. And citing one’s own research while taking other research out of context is not enough to be evidence of anything.

Throughout the history of vaccines, even before Edward Jenner’s breakthrough, people like Cotton Mather were bullied and their lives threatened for advocating for variolation against smallpox. Included in those early criticisms of vaccination and variolation were a number of publications in different forms — though mostly in print at the time — threatening all sorts of implausible complications from receiving a weakened version of a germ.

For example, a cartoon claimed that receiving Jenner’s vaccine would cause a person to become cow-like. (The Jenner vaccine was based on cowpox, a smallpox-like infection found in cattle.) Of course, the cartoon was an exaggeration, but plenty believed that it was true. It was an early version of “Fake News.” (Read the rest of the story behind that cartoon. It’s quite interesting.)

Dr. Deisher has been speaking out against vaccines based on the use of fetal cell tissue cultures for a while now. Her claims have been previously debunked by scientists who point out some of her creativity in the use and display of data along with the lack of plausibility to her claims. Nevertheless, her claims have become talking points for those opposing vaccination, as one can see in the news report from Seattle.

Like in Jenner’s time, the best inoculation against misinformation and lies from anti-vaccination activists is to know the science (or lack thereof) behind their claims, and to be a little skeptical of claims by people who cite their research and not much else.

Author: René F. Najera, DrPH

I am the editor of the History of Vaccines site, an online project by the College of Physicians of Philadelphia. All opinions expressed on these blog posts are not necessarily those of the College or any of my employers. Check out my professional profile on LinkedIn: Feel free to follow me on Twitter: @EpiRen

11 thoughts

  1. So if this is all bull**** …WHO ARE ‘the three expert scientists” who refute the information . I wont hold my breath waiting for an answer !

    1. The blog post doesn’t mention that they are “expert scientists” as you quoted the article to read. Nevertheless, they are experts, and their background information can be found on the link provided in the blog post:

      They are Angeline Rouers, immunologist:
      Maurizio Vacca, immunologist and virologist:
      Teja Celhar, expert on autoimmunity:

      Thank you for reading.

    2. Interesting but Dr Deisher is challenged by THREE scientists. Am I to infer that only three scientists read his report, not perhaps seven? These scientists may have made a valid criticism, or perhaps nots. Where is Dr Deisher’s reply?

  2. You first…..vaccinate your children first. My children, now adults, were never vaccinated and never got sick. No flu, no ear aches, no allergies, no rashes, no nothing. They grew up healthy and remain so. They have healthy un vaccinated children of their own and I am glad that we chose the path of the Almighty and not the path of mad scientists… people, doctors who vax, should all be jailed for crimes against humanity.

  3. This piling on, slyly equating Deisher to 19th century opponents of all vaccination. She opposes vaccines employing fetal dna.

  4. I am interested to know if the research on methylated DNA is published, and if so where it may be found, and if it is a single study, or several. I am not anti-vax but I think we can all agree that the patient should be given an informed choice by being given the full information about a vaccine just like any medication- of the risks associated.

  5. “Basically, if it was that easy for fetal DNA to get into our DNA through vaccination and cause some sort of change, gene therapy would be effortless.”

  6. very difficult times..when so many “experts” refute each other’s reasearch..what is the lay person to believe? Having read some of Dr Deisher’s work, I found that she was careful not to make 100% claims in any of her points, but seemed to be flagging “potential” problems with the vaccine industry which people would otherwise have no idea about.. ..which surely is a worthwhile task and it would be unwise at this moment in time to disregard her concerns…we need people who are willing to do this surely? I am willing to consider anyone’s opinion, who is putting their career and financial security on the line to try and keep a check on progress…

    1. Thank you for reading. However, Dr. Deisher has made plenty of absolutist statements on vaccines, almost all of them wrong:

      It is very wise to disregard the concerns of known anti-science and anti-vaccine activists, especially when over 375,000 people have died, many from the consequences of anti-science policies and viewpoints.

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