Pig Transplant Research Has a Surprise: Bacon Is Safe for Some People Allergic to Red Meat

BLACKSBURG, Va. – Some people who develop a strange and scary allergy to red meat after a bite from a lone star tick We can still eat pork from a surprising source: Genetically modified pigs created for organ transplant research.

Don’t look for it in supermarkets. The company that created these special pigs shares their small offering, free of charge, with allergy patients.

“We’ve gotten hundreds and hundreds of orders,” said David Ayares, who runs Revivicor Inc., as he opened a freezer packed with packages of ground pork burgers, ham, ribs and pork chops.

The allergy is called alpha-gal syndrome, named after a sugar that is present in the tissues of almost all mammals—except people and some of our primate cousins. It can cause a serious reaction hours after eating beef, pork or any other red meat, or certain mammalian products such as milk or gelatin.

But where does organ transplantation come in? There are not enough donated human organs to go around, so researchers are trying to use pig organs – and that same alpha-gal sugar is a big barrier. It causes the human immune system to immediately destroy an organ transplanted from a common pig. So the first gene that Revivicor inactivated when it began genetically modifying pigs for animal-to-human transplants was the one that produces alpha-gal.

Although xenotransplants are still experimental, Revivicor’s program “GalSafe” pigs it gained Food and Drug Administration approval in 2020 to be used as a food source and a potential source for human therapeutics. The FDA determined that there was no detectable level of alpha-gal in multiple generations of pigs.

Revivicor, a subsidiary of United Therapeutics, is not a food company – it researches xenotransplantation. It has yet to find anyone in the agricultural sector interested in selling GalSafe pork.

Still, “this is an FDA-approved research pig, so let’s get it to patients,” is how Ayares describes the start of shipments a few years ago.

Revivicor’s GalSafe herd is housed in Iowa and to keep their numbers in check, some of the meat is processed periodically at a U.S. Department of Agriculture-certified slaughterhouse. Revivicor then sends frozen shipments to patients with alpha-gal syndrome who have filled pork orders.

Thank you letters recounting the joy of eating bacon again line a bulletin board near the freezer at Revivicor’s corporate office.

Separately, on a Revivicor farm in Virginia, there are pigs with various genetic modifications for xenotransplant research, including a GalSafe pig that was the source of a recent experimental kidney transplant at NYU Langone Health.

And this raises the question: After removing the transplantable organs, could the pig be used for meat?

No. The strong anesthesia used so the animals don’t feel pain during organ removal means they don’t meet USDA rules for drug-free foods, said United Therapeutics spokesman Dewey Steadman.

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