Fact Check: Here's the Deal With Trump's Antibody Cocktail and Fetal Cells

A person infected with SARS-CoV-2
A person infected with SARS-CoV-2
Photo: SAUL LOEB / AFP (Getty Images)

The inevitable happened, and Donald Trump wound up hospitalized with covid-19. But now Trump is supposedly recovered and back to his usual business, like recording galaxy-brain videos calling his infection a “blessing from God.” One thing that the president has said may well be true: that he recovered with the help of a still-experimental monoclonal antibody cocktail produced by drugmaker Regeneron, called REGN-COV2.


This treatment was made possible in part thanks to fetal tissue research that happened over 40 years ago, though no actual embryonic stem cells were used in its production or development. The hypocrisy here is that the Trump administration halted federal fetal tissue research in 2019, a blow to medical science.

Some of Trump’s critics have taken this connection a little too far. Take Democratic Representative Ted Lieu, for example, who tweeted out documents Regeneron has posted to its web site:

The representative’s claim spread far and wide, racking up over 28,000 retweets and over 64,000 likes as of Thursday afternoon. A search for “human embryonic stem cells” on Twitter shows that it has been a near-constant subject of discussion all week. One tweet making the claim REGN-COV2 was “made with stem cells” and has 81,000 retweets and over 324,000 likes, while another has over 5,300 retweets and 11,800 likes. Numerous other identical claims have gone viral on Twitter, and stem cell claims are circulating on Facebook, too, sometimes with the implication that Trump’s recovery hinged on some relatively recent abortion.

To be clear, Regeneron’s antibody cocktail wasn’t produced using any human embryonic stem cells, though it was tested with the help of line of cells that was originally derived from aborted fetal tissue more than 40 years ago. This particular cell line—which, again, was never actually in a fetus—is widely used in scientific research and has been cultured again and again over the decades.

Neither of the two companies working to develop monoclonal antibodies effective against the SARS-CoV-2 virus have used embryonic stem cells in the process.

Per Science Mag, Regeneron’s monoclonal antibody cocktail and another being made in collaboration between AstraZeneca and Vanderbilt University were developed via a technique that involves harvesting B cells from consenting adults (or laboratory mice) who had recovered from the virus, then identifying which produced antibodies are effective against it. They then injected the genes to produce those antibodies into epithelial cell lines derived from the ovaries of Chinese hamsters. (“Chinese hamster” is the common name for the species C. griseus and does not suggest anything about where the hamsters were necessarily located.) Hamster ovary cells are utilized in a broad spectrum of medical research. That part of the process doesn’t involve anything related to a human fetus.


Lieu described the posted document as showing that “Regeneron, the experimental drug” relies on “human embryonic stem cells.” The document he posted is actually a position statement from Regeneron—the corporate entity, not its as-yet-unnamed drug—on the use of stem cells published in April 2020, when the company was in the early stages of its research on covid-19 antibodies. The statement merely establishes that Regeneron conducts stem cell research in general. It also states that when Regeneron conducts such research, it more commonly relies on mouse or adult human stem cells than it does on embryonic stem cells created by in vitro fertilization.

That document isn’t referring to Regeneron’s treatment, company spokesperson Alexandra Bowie wrote via email to Gizmodo, because it doesn’t use stem cells.


“... This is our general position statement on stem cell use,” Bowie wrote. “This particular discovery program (REGN-COV2) did not involve human stem cells or [embryonic stem cells].”

Lieu’s office didn’t respond to a request for comment from Gizmodo asking what sources they had to back up the claim the antibody cocktail “relied on ‘human embryonic stem cells.’” However, some science-minded folks on Twitter noticed that Regeneron’s own supplementary research material referenced human embryonic cells—specifically a derivative of the widely utilized HEK 293 line, HEK293T, with HEK standing for “human embryonic kidney”—as playing a role in production.


To a layperson, the technical language used to describe the process may read as indicating fetal cells are an ingredient in REGN-COV2. Back in 1972, a team of Nordic researchers working with the FDA to crank out the first vaccines for HIV originally cultivated HEK 293 from the kidneys of an aborted fetus, just like the name suggests.

This isn’t the first time that the origins of this specific cell line have made headlines. Back in 2011, pro-life groups lost their shit after discovering that a San Diego-based biotech company that helps create the flavors behind Pepsico and Kraft’s products was actually using HEK to do so. As Snope’s article on the topic points out, these rumors swirled around for years, leading an entire longstanding mythos that your mac and cheese or diet soda might contain fetal tissue. The claims, in many ways, sound nearly identical to the current yelling about REGN-COV2.


Suffice to say, the Pepsico and Trump cocktail rumors are off base. As science writers at the time explained, HEK is a cell culture, meaning that it’s the result of embryonic cells pulled from a single aborted fetus back in 1972 doing what those embryonic cells are particularly adept at doing: multiplying, and multiplying fast. The HEK cells used by the San Diego company were engineered to mimic taste receptors and quickly test new flavors in a laboratory setting; they never came anywhere close to a production line. In Regeneron’s case, the HEK 293T cells were used to cultivate pseudoparticles that mimic the “spike” protein of the coronavirus, which helps the virus invade cells.

Exposing antibodies to these pseudoparticles allows scientists to study how the antibodies might respond to an actual invading coronavirus. It’s not part of the produced drug, just like body armor (usually) doesn’t come with bullets stuck in it.


“The 293T cell line was originally derived from human embryonic kidney cells (back in the 1980s at Stanford University), but is an immortalized epithelial cell—again, not a stem cell,” Bowie told Gizmodo. “These cells were transfected and used in production of a ‘pseudoparticle’ that mimics the virus’ spike protein and allowed us to test neutralization ability of our antibodies against the virus.”

“The HEK293 cell lines are common research tools used to express many kinds of proteins, as briefly described here,” Antibody Society executive director Janice M. Reichert, an expert on antibody therapeutics, wrote to Gizmodo. “By now, there are numerous derivatives of the original cell line. HEK293 cell lines are typically purchased (e.g., from ATCC) by labs, not generated de novo using the method described in the original paper.”


In any case, HEK 293 has been cultured so many times over multiple decades that its origin barely matters—unless, of course, you are vehemently opposed to any kind of fetal tissue research. Its versatility has made this line a staple of medical science. HEK 293T has itself been further modified and cultivated. Neither is a line of stem cells, which are undifferentiated or partially differentiated cells with the ability to develop into specialized cells. The distinction is important, as the ability of pluripotent stem cells to differentiate into pretty much anything offers hope for novel treatments for everything from physical trauma to genetic and/or degenerative conditions.

As Snopes put it in its Pepsico debunker:

Saying that possessing a digitized image of a photocopy of a picture of a Beethoven manuscript is the same as “owning a document in Beethoven’s own handwriting” — the original is not present in substance, only in a multi-generational, representational form.


The underlying criticism of Trump—that he is the beneficiary of research he opposes—is fair. In June 2019, the Trump administration moved to cut off federally funded research at the National Institutes of Health utilizing fetal cell tissue collected after an elective abortion. It also forced scientists receiving grants from the NIH to go through a more exhaustive review process, including a “Human Fetal Tissue Ethics Advisory Board” stocked with opponents of fetal tissue research. An investigation by Democrats in Congress later found, unsurprisingly, that the White House’s decision was motivated almost entirely by political concerns and impeded critical medical research, including coronavirus treatments.



their website mentioned development of REGN-COV2 was aided by mice which have been genetically modified to have a human immune system, and i didn’t know that we could do that. sounds so sci-fi.