A Tick Bite Made Them Allergic to Meat

A few months ago, Candice Matthis and Debbie Nichols sat down with their husbands to have some bacon. It was an unremarkable scene, except for two details.

First, there were the EpiPens, which Matthis and Nichols both had ready in case of emergency. The two women can’t eat red meat, not after they were each diagnosed with a dangerous red-meat allergy that develops, oddly enough, after tick bites. They had bonded as friends over their strange shared fate, where a strip of bacon could send them into anaphylactic shock. Matthis is so sensitive that even the airborne particles wafting off a pan of cooking meat typically make her sick. But this time, nothing happened to her as the bacon sizzled. Her EpiPen remained untouched. Nichols made herself a BLT. “It had been years,” she told me. And for her, too, nothing happened, except that she remembered how good a BLT tasted.

Which brings us to the second remarkable thing about the meal. This bacon was not your regular bacon, or even your fancy pasture-raised, thick-cut bacon; this bacon was so exclusive that it’s not available in stores. It came from Revivicor, a biotechnology company that genetically modifies pigs to create organs suitable for transplant into humans..) It just so happens that the same molecule—a sugar called alpha-gal—that causes the human immune system to reject pig organs also causes the tick-associated red-meat allergy, known as alpha-gal syndrome. To make a pig whose organs could be harvested for transplant, Revivicor first had to make an alpha-gal-free pig. And when it did, the company realized that transplant surgeons weren’t the only ones interested.