This one man has saved the lives of more than 2 million babies.

They call him the man with the golden arm.

As James Harrison heads off to his 1,100th blood donation it would be easy to just think of him as a good guy. One of those helpful types in society who do their bit to give back.

They are the type that these days we tend to give a passing thought to and then rush on with our busy lives giving more time to a video of an entertaining cat or a reality TV star’s pregnancy.

But this man is worth more than a pausing thought or a virtual pat on the back, this man deserves our immense gratitude because there is no doubt that this man has saved the life of someone you know.

Or even your baby.

James Harrison, 78,  is your ordinary grandfather – he likes taking holidays with his wife, he collects stamps and goes for walks along the beach, and each and very week for the past 60 years he has visited a blood bank and donated plasma from his right arm.

Hardly ever missing a week in 60 years.

And in the process saving the lives of more than 2.4 million babies with his blood alone.

A remarkable achievement.

Known as “The Man with the Golden Arm,” the gold that runs through his veins is unique and was discovered when he went in for a chest operation at the age of 14.

“In 1951, I had a chest operation where they removed a lung — and I was 14,” Mr Harrison told CNN.

“When I came out of the operation, or a couple days after, my father was explaining what had happened. He said I had (received) 13 units (liters) of blood and my life had been saved by unknown people. He was a donor himself, so I said when I’m old enough, I’ll become a blood donor.”

And he did. But it was then that doctors discovered his blood had the potential to save lives.

Jemma Falkenmire, of the Australian Red Cross Blood Service told CNN  “In Australia, up until about 1967, there were literally thousands of babies dying each year, doctors didn’t know why, and it was awful.”

“Women were having numerous miscarriages and babies were being born with brain damage.”

The condition, called Haemolytic Disease of the Newborn, potentially affects 17 per cent of babies and is caused when a mother has Rh (D) negative blood and her baby is Rh (D) positive.

What is Haemolytic Disease of the Newborn? From CSL Behring. 

Haemolytic disease of the newborn is caused when the blood group of the mother and baby are not compatible.

People can belong to one of four blood groups, A, B, AB and O, which are carried on the red blood cells. The other important difference in people’s blood is called rhesus factor, which is also found in the red blood cells. People who are rhesus positive have a substance known as D antigen on the surface of their red blood cells. People who are rhesus negative do not have the D antigen on their blood cells.

During pregnancy and childbirth the rhesus factor D can have an important role to play when a RhD-negative mother is expecting a RhD-positive baby. The placenta acts as a barrier between the red blood cells of the mother and baby. However, sometimes small amounts of the baby’s blood can cross over into the mother’s blood stream.

If any of the blood cells from a RhD-positive baby get into the blood of a RhD-negative woman, she will react to the D antigen in the baby’s blood as though it is a foreign substance and will produce antibodies. This is called ‘rhesus sensitisation’.

As a general rule, the first child that triggers this sensitisation does not suffer any adverse consequences, as it will already have been born by the time antibodies have developed. However, if the woman goes on to become pregnant with a second RhD-positive child, antibodies may cross into the baby’s blood and attack the red blood cells. This is called ‘haemolytic disease of the newborn’.

Haemolytic Disease of the Newborn can be mild but can also lead to jaundice, brain damage or even the death of the child. With further RhD-positive children, the antibody reaction becomes faster and more serious.

Doctors found that a product derived from James’ blood, called Anti-D injected into at-risk mothers saved the lives of their babies.

Every batch of Anti-D ever made in Australia has some of James Harrison’s blood in it, and one batch even in a remarkable twist of fate even helped to protect the life of his unborn grandson.

A news report on James’s remarkable contribution. Post continues after video. 

James Harrison comes across as a humble man – one who knows the vital importance of his donations, but who doesn’t see himself as special.

“It’s red, there’s nothing different to ordinary blood and it comes out the same way” he told the ABC’s RN Drive.

But Mr Harrison we are here to tell you each and every woman and child whose lives you have saved begs to differ.

And the Red Cross agrees.

“Every bag of blood is precious, but James’ blood is particularly extraordinary,” Ms Falkenmire told CNN.

“And more than 17% of women in Australia are at risk, so James has helped save a lot of lives.”

It is not known why James’s blood is so special, doctors say it might be from the transfusions he received when he was 14, after his lung surgery.

He’s one of only 50 people in Australia known to have the antibodies

Speaking to the ABC’s RN Drive this week she said, “James is very special to us.”

“We have about 500,000 blood donors across Australia, but we only have about 50 donors who have that antibody in their blood, so James is very rare to us.”

In a short period of time James will be forced to retire his special blood as the Red Cross have a cut off donation age of 80. They are now searching for someone to step into his role.

“I don’t think anyone will be able to do what he’s done, but certainly we do need people to step into his shoes,”

“I guess for us the hope is there will be people who will donate, who will also … have this antibody and become life savers in the same way he has, and all we can do is hope there will be people out there generous enough to do it, and selflessly in the way he’s done.”

James Harrison on behalf of so very many women you have helped we say thank you.

If you want to donate, you can call 13 14 95 or visit donateblood.com.au.