James Harrison was born in 1936. At the age of 13, he underwent a major chest surgery to extract a lung with metastasised pneumonia, and required 13 liters of blood.[3] After surgery, he was in the hospital for three months. Realising that the blood had saved his life, he made a pledge to start donating blood as soon as he turned eighteen.[1]
In the fifty-six years since his first donation, he has donated more than 1,000 times. This amount of donations is also a world record. After the first few donations, it was discovered that his blood contained a rare antibody that prevents infants who receive his blood from dying of Rhesus disease, a deadly form of anemia. This blood is given to one in ten women whose blood is not compatible with that of their children.[1][4]
The uniqueness of his blood also created the Anti-D vaccine. When he originally began donating blood, his life was insured for one million dollars.[1] He reached his 1,000th donation in May 2011. His blood has helped to save around two million babies with hundreds of thousands of women being treated with his antibodies
via en.wikipedia.org