内容摘要：AP’s Lisa Dwyer reports there are new requirements for COVID vaccines for healthy adults and children.

AP’s Lisa Dwyer reports there are new requirements for COVID vaccines for healthy adults and children.

Behind that protective barrier are some of the world’s cleanest pigs. They breathe air and drink water that’s better filtered against contaminants than what’s required for people. Even their feed gets disinfected – all to prevent them from picking up any possible infections that might ultimately harm a transplant recipient.“We designed this facility to protect the pigs against contamination from the environment and from people,” said Matthew VonEsch of United Therapeutics, Revivicor’s parent company. “Every person that enters this building is a possible pathogen risk.”

The Associated Press got a peek at what it takes to clone and raise designer pigs for their organs – including a $75 million “designated pathogen-free facility” built to meet Food and Drug Administration safety standards for xenotransplantation.Thousands of Americans each yearfor a transplant, and many experts acknowledge there never will be enough human donors to meet the need.

Animals offer the tantalizing promise of a ready-made supply. After decades of failed attempts, companies including Revivicor,and Makana Therapeutics are engineering pigs to be more humanlike.

So far in the U.S. there have been four “compassionate use” transplants, last-ditch experiments into dying patients — two hearts and two kidneys. Revivicor provided both hearts and one of the kidneys. While the four patients died within a few months, they offered valuable lessons for researchers ready to try again in people who aren’t quite as sick.

Now the FDA is evaluating promising results from experiments in donated human bodies and awaiting results of additional studies of pig organs in baboons before deciding next steps.transplanted in November and a

transplanted in January. A U.S. clinical trial is about to begin.Nearly three weeks after the kidney surgery the Chinese patient “is very well” and the pig kidney likewise is functioning very well, Dr. Lin Wang of Xijing Hospital of the Fourth Military Medical University in Xi’an told reporters in a briefing this week.

Wang, part of the hospital’s xenotransplant team, said the kidney recipient remains in the hospital for testing. Chinese media have reported she is a 69-year-old woman diagnosed with kidney failure eight years ago.But Wang pointed to a potential next step in xenotransplantation — learning to transplant pig livers. His team reported Wednesday in the journal Nature that a pig liver transplanted into a brain-dead person survived for 10 days, with no early signs of rejection. He said the pig liver produced bile and albumin — important for basic organ function — although not as much as human livers do.