Over the course of six decades, Harrison became one of the most prolific blood donors in history, offering a life-saving antibody known as Anti-D.

This crucial antibody is used to create a treatment for pregnant mothers at risk of developing hemolytic disease of the fetus and newborn (HDFN) — a condition that occurs when a mother’s immune system mistakenly attacks her unborn baby’s red blood cells, potentially leading to severe anemia, heart failure, or even death.

Harrison’s daughter, Tracey Mellowship, reflected on his extraordinary legacy, saying: “He was also very proud to have saved so many lives, without any cost or pain. It made him happy to hear about the many families like ours, who existed because of his kindness.” Harrison’s journey as a donor began after he underwent major chest surgery at the age of 14, which required a massive blood transfusion.

Grateful for the blood that had saved his life, he made a pledge to give back. He started donating plasma at 18 and continued every two weeks until he was 81. Over his lifetime, he made more than 1,100 blood donations.

“He always said it does not hurt, and the life you save could be your own,” Mellowship added.

In 2005, Harrison earned the world record for the most blood plasma donated — a title he held until 2022 when a U.S. donor surpassed his total. His contributions were instrumental in the development of the Anti-D treatment, which has dramatically reduced infant mortality rates from HDFN.