Over the course of six decades, Harrison became known as one of the world’s most significant blood donors — providing a precious life-saving antibody in his blood, Anti-D. Although it was never fully confirmed how this antibody ended up in his system, reports have said it may be to do with a major blood transfusion Harrison had at the age of 14.

Later, it was discovered that Harrison’s blood was rich in the antibody and could go towards a drug that can protect newborns against Rhesus disease, also known as haemolytic disease of the foetus and newborn (HDFN).

It’s a very harsh condition that, as a result of an incompatibility between a baby and their mother’s red blood cells, the mother’s immune system misinterprets the child as a threat. By sending antibodies to attack the baby, a mother’s bodily defenses can lead to a variety of damages including brain damage, heart failure, and even the loss of their life.

From the age of 18 in 1954, for every two weeks up until the age of 81, Harrison had made over 1,100 blood donations. Those regular donations even earned him the world record for the most plasma donated in 2005, which he kept up until 2022 when a US-based man overtook him.