The unique antibodies in James Harrison's blood helped make him something of an Australian superhero. His regular plasma donations over decades are believed to have helped save 2.4 million babies Down Under.
His weekly donations earned the 81-year-old the nickname "The Man With the Golden Arm."
His donated plasma is used to develop a life-saving medication, Anti-D, given to moms whose blood is at risk of attacking their unborn babies. The condition occurs when a woman has rhesus-negative blood while her fetus is rhesus-postive, a trait inherited from its father. In such pregnancies, a mother sensitized to rhesus-positive blood during a previous pregnancy may develop antibodies that destroy the fetus' blood cells.
"Every bag of blood is precious, but James' blood is particularly extraordinary," Jemma Falkenmire of the Australian Red Cross Blood Service told CNN. "Every batch of Anti-D that has ever been made in Australia has come from James' blood."
Harrison began donating blood 60 years ago, but switched to plasma donation after a decade when researchers discovered his unique antibodies.
It's uncertain how he developed his special antibodies. Doctors speculate that the large amount of transfused blood he received during a chest operation in 1951 could be responsible. That experience made him vow to donate blood when he was old enough.
"It's something I can do. It's one of my talents, probably my only talent—that I can be a blood donor," Harrison told CNN.
But now Harrison has retired; blood donors can't be 81 or older in Australia. The blood service estimates up to 50 other Australians share his unique antibodies.