Patients are so tired of waiting years for a transplant that they are signing up in droves to receive vital organs from pigs.

On a farm in the state of Virginia, in the southern United States, David Ayares and his research teams are breeding genetically modified pigs to transplant their organs into human patients. Revivicor, the biotechnology company led by Ayares, is at the forefront of research into xenotransplantation – the implantation of animal organs into humans – which aims to solve a chronic organ shortage that leads to death thousands of Americans every year.

Andrew Caballero-Reynolds / AFP—Getty Images