Faith, Fact, and Pretext: Further Examination of the Fetal Cell Argument Against COVID-19 Vaccines

Yesterday’s email solicited quite the response, and while we received some who liked the article, others did not. One alert reader sent a note complaining about the lack of footnotes in yesterday’s message about HEK-293 (the fetal cell strain that’s been used since the 1970s to test various household products). That’s a fair assertion, so I’ve tried to update the article to include footnotes and provide some context for my assertion that the use of HEK-293 lines is much more expansive (and probably less troubling) than many people think. None of this constitutes medical or legal advice.

A claim about medical research should survive the reading of its own footnotes.

That is a useful rule for the debate over HEK-293, a family of human cells used in laboratories. Research involving these cells reaches into a long list of familiar substances: acetaminophen, ibuprofen, aspirin, allergy drugs, heartburn medicines, antidepressants, sugar, and artificial sweeteners.

This isn’t designed to change your mind about whether the use of HEK-293 is unethical or violates your religious beliefs, but rather to zoom out on the scope of the objection.

Under the landmark Supreme Court decision in United States v. Ballard, 322 U.S. 78 (1944), secular courts and government bodies are strictly forbidden from evaluating the truth, plausibility, or internal theological consistency of a claimant’s religious beliefs. Faith cannot be subjected to judicial cross-examination. Furthermore, under Title VII of the Civil Rights Act of 1964 and First Amendment precedents, an individual need not demonstrate that their objection represents an official tenet of a recognized church; religious protections encompass personal, non-traditional, and even idiosyncratic spiritual convictions (Thomas v. Review Board of the Indiana Employment Security Division, 450 U.S. 707, 714 (1981)).

However, Ballard establishes that while the veracity of a religious belief is shielded from secular review, its sincerity is not. Courts and employers are fully empowered to determine whether an employee’s asserted belief is truly and sincerely held, or whether it constitutes a pretextual claim designed to mask secular, medical, or political preferences.

Herein lies the a potential weakness of the fetal cell argument:

1. The Inviolability of the Moral Tenet: The assertion “I have a religious conviction that forbids taking a product touched by an aborted fetus” is a protected subjective belief.

2. The Testability of the Empirical Premise: The claim that “The COVID-19 vaccine is morally forbidden on this basis, but Tylenol, Motrin, Pepcid, and childhood MMR vaccines are not” introduces a verifiable empirical assertion into an otherwise subjective claim.

During the mandate litigation, this contradiction manifested directly. In evaluating whether an objection was sincere or pretextual, employers routinely administered supplemental questionnaires asking claimants whether they had ever taken over-the-counter pain relievers or other pharmaceuticals tested on HEK-293.

When a claimant routinely ingests acetaminophen or routinely administered varicella and MMR vaccines to their children, their assertion that a novel COVID-19 vaccine uniquely violates their faith encounters immediate evidentiary jeopardy. Under Title VII jurisprudence, extensive inconsistency in conduct serves as prime objective evidence of insincerity.

Why? Because in 2021, saying “I don’t trust this novel mRNA technology,” “I already had COVID and possess robust natural immunity,” or “I despise government coercion” did not provide an exit under Title VII. Secular skepticism, political resentment, and personal risk assessments do not grant statutory accommodations. An abortion-derived religious exemption did.

The fetal cell argument was seized upon not out of an agony of conscience, but as a tactical trump card, a cynical legal loophole masquerading as pious conviction.

This tactical dishonesty carries a devastating price. When litigants weaponize religious liberty as a bad-faith defense, they taint the entire enterprise of legal accommodation. They invite judges, employers, and an already skeptical secular public to view all conscience claims as self-serving pretexts. The genuine religious minority (the Seventh-day Adventist seeking Sabbath accommodation, the Sikh fighting for his articles of faith, or the pacifist facing military conscription) will bear the cost of this cynicism when courts inevitably tighten the screws on the sincerity test.

There is plenty to scrutinize, challenge, and litigate regarding the state’s heavy-handed pandemic response and the pharmaceutical industry’s aggressive mandates. But conscience must be built on truth, not convenient fictions.

Why does this matter?

When litigants weaponize religious liberty as a bad-faith defense, fully aware of their own inconsistencies, they taint the entire enterprise of legal accommodation. They invite judges, employers, and an already skeptical secular public to view all conscience claims as self-serving pretexts. The genuine religious minority (the Seventh-day Adventist seeking Sabbath accommodation, the Sikh fighting for his articles of faith, or the pacifist facing military conscription) will bear the cost of this cynicism when courts inevitably tighten the screws on the sincerity test.

(Click on the red language to visit the links.)

So let’s take a serious look at HEK-293.

To begin, we should acknowledge that testing an ingredient, testing a finished medicine, and using cells to manufacture a treatment are different activities.

HEK-293 began as a cell line established in 1973. Its starting material was human embryonic kidney tissue. Scientists have continued growing descendants of those cells in laboratories. The ATCC cell collection describes their origin, and Canada’s National Research Council documents the creation of the line. Modified descendants, including HEK293T, belong to the same family.

Scientists can give these cells particular proteins to study. Some proteins act as sensors. Others form tiny gates that let charged particles pass through a cell’s surface. Researchers then expose the cells to a substance and measure the response.

Does the substance activate a sensor? Block a gate? Enter the cell? Damage it?

Those questions can help explain a medicine’s effects. They do not turn a dish of cells into a complete human being. As the FDA explains, laboratory research cannot replace studies of how a drug behaves in people.

Start with the medicine cabinet.

Acetaminophen, the pain-relieving ingredient in Tylenol, was tested in HEK-293 cells in a study of cell survival, growth, and gene activity. Ibuprofen, found in Advil and Motrin, was examined in a study measuring damage to cultured kidney cell lines. These papers document research on the ingredients. They do not establish that bottles bearing those brands were tested.

Naproxen, the ingredient in Aleve, was tested on HEK-293 cells carrying a receptor involved in pain signals. The researchers measured its effects on that receptor. Aspirin was examined in another experiment using HEK-293 cells, this time involving a receptor that responds to heat and capsaicin, the substance that makes chili peppers hot.

The allergy shelf supplies more examples. Diphenhydramine, found in U.S. Benadryl products, was tested for its effects on a sensory channel in HEK-293 cells. Loratadine, the ingredient in Claritin, was studied for its effects on a channel that allows calcium into cells. Fexofenadine, found in Allegra, appeared in research on drug transport and green tea compounds.

Dextromethorphan, used in Delsym and some Robitussin products, was examined using an HEK-293-based system in a study of a receptor involved in allergic-type reactions. The purpose matters: this particular paper investigated a possible unwanted effect, not how the medicine stops a cough.

Heartburn medicines belong in the account, too. Researchers used modified HEK-293 cells to examine how omeprazole, esomeprazole, lansoprazole, rabeprazole, and famotidine affected a transport protein. The study concerned possible interactions with methotrexate, another medicine. Familiar products containing these ingredients include Prilosec, Nexium, Prevacid, AcipHex, and Pepcid, respectively. A separate study examined pantoprazole, the ingredient in Protonix, and the release of a protein involved in allergic responses.

Prescription drugs widen the list. A metformin study used HEK-293 cells to examine how a transport protein affects entry of the diabetes medicine into cells. An atorvastatin study examined transport of the cholesterol drug known by the brand Lipitor. Research on albuterol, formoterol, and salmeterol used modified HEK-293 cells to investigate transport proteins relevant to inhaled medicines.

One study of a heat-activated cell channel tested seven antidepressants: sertraline, fluoxetine, paroxetine, citalopram, escitalopram, duloxetine, and amitriptyline. Readers may recognize the first six as the ingredients in Zoloft, Prozac, Paxil, Celexa, Lexapro, and Cymbalta. The same experiment examined pregabalin and lidocaine. Its methods expressly identify HEK-293 cells.

That is already dozens of drug ingredients. It is a documented sample, not a complete inventory of every medicine ever studied.

The record reaches beyond medicine.

A 2021 sweet-taste study placed human taste receptors in HEK-293 cells and tested sucrose, fructose, allulose, saccharin, and two sweet compounds associated with stevia, rebaudioside A and rebaudioside M.

Sucrose is ordinary table sugar. Its appearance in such research does not mean sugar was invented through this cell line. It means researchers used the cells to investigate how sugar activates a taste receptor.

Another taste-receptor study included aspartame, sucralose, acesulfame potassium, neotame, cyclamate, and glutamate in experiments using HEK-293 cells. Glutamate is associated with the savory taste of MSG. These were studies of how taste works. They do not establish that every drink or food containing those substances was tested.

Other examples include caffeine in sensory-channel research, menthol in similar experiments, and EGCG, a green tea compound, in skin-related research. A further study used retinol as a comparison substance in HEK293T experiments. None of those findings licenses a claim about every coffee brand, mint toothpaste, or skin cream.

The often-cited 2002 paper associated with Senomyx researchers documents work on sweet and savory taste receptors. It is evidence of a research method. It is not a verified shopping list of finished sodas, soups, or snacks. Naming a company cannot fill a gap in product-specific evidence.

Vaccines show why the distinctions matter.

In the original Pfizer-BioNTech vaccine program, researchers used HEK293T cells to examine production of the intended viral protein after exposure to vaccine RNA or its formulation. The development paper describes those experiments. The original Moderna development paper documents related cells in experiments on protein production and antibody activity.

For AstraZeneca’s Vaxzevria, the connection went further. Its official product information states that the modified virus was produced in genetically modified HEK-293 cells. That is a manufacturing role. It should not be described as merely testing an ingredient.

Nor should anyone claim that scientists never test finished formulations. A published study exposed 293T cells to Pfizer and Moderna vaccine formulations. A statement beginning with “never” needs more evidence than a reassuring comparison.

What follows from this record?

A person may object to the historical source of a cell line. Another may distinguish research on descendants of those cells from obtaining new tissue. Someone else may draw a line between laboratory testing and manufacturing. Those are positions that can be stated and debated.

But the factual claim must match the evidence.

If the objection covers any research involving HEK-293 and a substance, the discussion reaches well beyond vaccines. It includes numerous familiar drug ingredients, sweeteners, and other everyday compounds.

If the objection concerns manufacturing, a paper about later laboratory testing does not establish that connection. If it concerns a particular company, a university experiment using a chemical does not establish that the company commissioned the work.

The question of what is in a product is separate from the question of what happened during research. Showing that a chemical was tested on human cells does not show that those cells became an ingredient. Showing that a product contains no such cells does not erase the research history.

The evidence is broad enough without embellishment. There is no need to invent a connection, inflate a study into a claim about an entire brand, or mistake an experiment for a declaration of complete safety.

An ethical argument can demand a great deal. It should begin by demanding accuracy from itself.

SCIENTIFIC LITERATURE ON THE BREADTH OF HEK-293 RESEARCH

• ATCC. (n.d.). 293 [HEK-293] (CRL-1573) [Cell-line catalog entry]. Retrieved September 21, 2026, from https://www.atcc.org/products/crl-1573

• National Research Council Canada. (2020, September 25). Recognizing the scientific impact of Dr. Frank Graham’s HEK 293 cell line. https://www.canada.ca/en/national-research-council/news/2020/09/recognizing-the-scientific-impact-of-dr-frank-grahams-hek-293-cell-line.html

• ATCC. (n.d.). 293T (CRL-3216) [Cell-line catalog entry]. Retrieved September 21, 2026, from https://www.atcc.org/products/crl-3216

• U.S. Food and Drug Administration. (2018, January 4). Step 3: Clinical research. https://www.fda.gov/patients/drug-development-process/step-3-clinical-research

• Coskun-Demirkalp, A. N., Tekcan, A., Cakir, M., & Donmez-Altuntas, H. (2025). Paracetamol induces apoptosis, reduces colony formation, and increases PTPRO gene expression in human embryonic kidney HEK 293 cells. Journal of Biochemical and Molecular Toxicology, 39(8), Article e70366. https://doi.org/10.1002/jbt.70366

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