BLACKSBURG, Va. (AP) — Some people who develop a weird and terrifying allergy to red meat after a bite from a lone star tick can still eat pork from a surprising source: Genetically modified pigs created for organ transplant research. Don't look for it in grocery stores.

The company that bred these special pigs shares its small supply, for free, with allergy patients. “We get hundreds and hundreds of orders,” said David Ayares, who heads Revivicor Inc., as he opened a freezer jammed with packages of ground pork patties, ham, ribs and pork chops.

The allergy is called alpha-gal syndrome, named for a sugar that's present in the tissues of nearly all mammals - except for 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 aren't enough donated human organs to go around so researchers are trying to use organs from pigs instead — and that same alpha-gal sugar is a big barrier.

It causes the human immune system to immediately destroy a transplanted organ from an ordinary pig. So the first gene that Revivicor inactivated as it began genetically modifying pigs for animal-to-human transplants was the one that produces alpha-gal. While xenotransplants still are experimental, Revivicor’s “GalSafe” pigs won Food and Drug Administration approval in 2020 to be used as a source of food, and a potenti.