"Every bag of blood is precious, but James' blood is particularly extraordinary", says Falkenmire.
An 81-year-old whose blood has helped to save more than two million babies has "retired" from donations. The occasion marked the end of a monumental chapter.
Jemma Falkenmire at the Australian Red Cross Blood Donor Service said "very few people have the these antibodies in such strong concentrations".
Harrison's blood has unique, disease-fighting antibodies that have been used to develop an injection called Anti-D, which helps fight against rhesus disease.
The disease occurs in pregnant women with Rh-negative blood. The disease causes multiple miscarriages, still births, and brain damage or fatal anaemia in newborns.
The illness develops when the pregnant women having Rh negative blood type carries baby having Rh positive blood, which the baby inherits from the father.
The blood becomes sensitized when the positive RHD blood is exposed to the negative blood and causes the mother's immune system to produce molecules that will fight the infection, called antibodies, that will destroy the cells. That could be deadly for the baby.
"His kindness leaves a remarkable legacy", the Australian Red Cross said in a statement.
Blood donations saved his life, so he pledged to become a blood donor.
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HDN killed thousands of Australian babies every year before scientists made their breakthrough Anti-D discovery in the 1960s.
James, who has been nicknamed "the man with the golden arm" is thought to be one of around 50 people in Australia who carry the antibodies. The medicine is given to mothers whose blood is at risk of attacking their unborn babies. "Every batch of Anti-D that has ever been made in Australia has come from James' blood".
The Red Cross Blood service pulled Australian birth data since 1964, factored in that 17 per cent of women received anti-d injections and calculated the risk of HDN deaths. It prevents women with rhesus-negative blood from developing RhD antibodies during pregnancy. More than three million does of Anti-D have been issued to Australian mothers with negative blood types since 1967.
"That resulted in my second grandson being born healthy", Harrison said. "And that makes you feel good yourself that you saved a life there, and you saved many more and that's great", he stated.
Ms Falkenmire said that up until 1967, 'there were literally thousands of babies dying each year, doctors didn't know why and it was bad. Australia became the first country in the world to be self-sufficient in the supply of Anti-D. He's now donated his plasma more than 1,000 times, but no matter how many times he's given blood there's one thing that will never change: "Never once have I watched the needle go in my arm", he says.
"I'd keep on going if they'd let me", Mr Harrison said. "It's something I can do".
His generosity as a continuous donor stems from a brush with death at the age of 14, when he had a chest operation, and committed himself to helping others by giving blood on a regular basis. The Australian researchers realised that they could combat HDN by using Anti-D injections, so Harrison switched over to make blood plasma donations to help people.
Ms Barlow agrees. "We'll never see his kind again. that he has been well and fit and his veins strong enough to continue to donate for so long is very, very rare", she said.