In 1954, what transplanted in Richard Herrick from his twin Ronald, the first successful instance of such a transplant?

Question

The first successful heart transplant from what animal to an adult human was made in Baltimore, Maryland, US, in January 2022?

Answer 1

Kidney transplants

The Boston transplantation, performed on December 23, 1954, at Brigham Hospital was performed by Joseph Murray, J. Hartwell Harrison, John P. Merrill and others. The procedure was done between identical twins Ronald and Richard Herrick to eliminate any problems of an immune reaction. For this and later work, Dr. Murray received the Nobel Prize for Medicine in 1990. The recipient, Richard Herrick, died eight years after the transplantation