Xenotransplantation

In January 2022, surgeons at the University of Maryland Medical Center transplanted a genetically modified pig heart into a dying 57-year-old patient named David Bennett Sr. He lived for two months. In September 2023, they did it again, with Lawrence Faucette, a Navy veteran ineligible for a human heart; he survived six weeks. In 2025, Tim Andrews received a gene-edited pig kidney at Massachusetts General Hospital, has now outlived every previous xenotransplant recipient, and in June threw the ceremonial first pitch at Fenway Park. These are pilot cases, not routine medicine. They are also no longer hypothetical.

What Has Changed Since 2018

When the book was written, xenotransplantation — the transplanting of organs across species — was a decades-old research programme with a long history of disappointment. The technical obstacles were severe. Pig organs, the most plausible source, are physiologically close enough to human ones to function but immunologically different enough to be rejected almost immediately. A further complication: pig genomes contain endogenous retroviruses (PERVs) that have long been a biosecurity worry for exactly this application.

CRISPR changed the equation. Since roughly 2020, two companies — eGenesis (a 2015 spinout of the George Church lab at Harvard) and Revivicor (a subsidiary of United Therapeutics) — have developed donor pig lines edited at dozens of sites. The edits silence PERVs, knock out pig antigens that trigger hyperacute rejection, and add human genes that dampen the recipient immune response. The 2022 Bennett heart carried ten such edits; subsequent generations carry more.

The Maryland heart transplants, the NYU and Mass General pig-kidney work, and a small but growing number of other procedures have established two things. First, the technology works — imperfectly, for limited durations, in patients who had no other option. Second, it fails in ways that remain partly mysterious. Bennett’s death was ultimately attributed in part to a porcine cytomegalovirus that had evaded pre-surgery screening. Faucette’s biopsies showed rejection signatures by two weeks. The immunology is not solved; it is being learned case by case.

The FDA has cleared the first clinical trial of pig-to-human kidney transplants, a pivotal transition from individual compassionate-use cases to a systematic research programme. The pipeline now points toward a possible registration trial by the end of the decade.

Why It Matters

The supply argument is extraordinary. The organ shortage kills roughly 30,000 people a year on waiting lists worldwide, with 668,000 patients waiting at any given time. A reliable supply of transplantable organs — effectively unlimited, compatible enough, and not requiring a dead human donor — would be one of the largest gains in medical history since antibiotics. This is the Too Valuable to Fail engine at full throttle, with consequences that will be difficult to slow once underway.

The biosecurity argument cuts the other way. Xenozoonosis — the risk of animal viruses crossing into humans via transplanted organs — is not a hypothetical concern. The Bennett case demonstrated that current screening is imperfect. A single xenotransplant recipient who becomes a reservoir for a novel porcine pathogen could, in the worst case, initiate an outbreak that the global public-health infrastructure is not well positioned to contain. This is Dual-Use Research and Biosecurity with the usual wording reversed: the dual use here is therapy with outbreak potential, rather than research with weaponisation potential.

The access argument is the book’s Power, Privilege, and Access question in one of its more concrete forms. If xenotransplantation becomes routine, who gets a pig kidney first? The current patients have been selected largely on medical desperation and consent-to-experimental-treatment criteria, which is appropriate for pilot cases and will not scale. Any national or international allocation regime that emerges will encode answers to “who deserves an organ” in ways that are still being debated for human-donor transplants.

The animal-ethics argument is the one that is hardest for the book’s frameworks to catch directly. The pig, in this account, is infrastructure — a precision-engineered organ source, housed in biosecure facilities, killed on a schedule set by human recipients. This is the industrial animal relationship taken to a new extreme. The book does not address animal moral status at length, and applying its frameworks here requires honest acknowledgement that we are extrapolating beyond what the book builds.

How the Book’s Frameworks Apply

Films outside the book’s twelve: Repo! The Genetic Opera (2008) sits in a B-tier cult register but takes the organ-as-commodity question as seriously as any mainstream film has. Okja (2017, Bong Joon-ho) is already on Claude’s film recommendations and handles the instrumentalised-animal question in a register that works with this page; pairing the two pages is useful.

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