>> it can't be manufactured. we can't live without it and there is a global shortage of this life-staiv saving substance. today we are talking about blood and blood donations. this is "vital signs." i'm dr. sanjay gupta. stay with me here. i know the sight oblood makes some people pass out. it fights infection, carries cells and nutrients throughout the body. more impressive is how it gets there. your circulatory is this vast and complex network of vessels. in fact, if you lined up all the blood vessels in your body

end-to-end, they would stretch around the earth two-and-a-half times. but what happens when something goes wrong is this when are you injured or sick? and you into ed the help of a complete stranger? to save your life? >> at the winceton churchill south of london, 60 students fill the classroom, listening to stewart phelps, a business manager at the school. he doesn't usually give talks to the stuvenlts on thdents, he un what it is to be a match. >> i signed up, there was an article i read it in hospital when i was in hospital, myself. the article that detailed, it came through, it said if you are a match for someone, you could potentially help them cure cancer, which was like really an exciting thing, to have a chance

to be. >> a good man. >> yes in 1990, stewart signed up for the anthony nolan register in the united kingdom. this was the first marrow registry in the world. now it's a global registry that surpassed 25 million potential donors world wide. >> it's been quite interesting to sort of wonder what it would be like and you you would be helping. >> years went by with no potential word on a match. in that time, he got married, had two kids. his family also experienced a devastateing loss. >> well, we had a situation about 11 e 11 years ago. we had a child who wasn't going to be able to survive when born i didn't want to accept that there was nothing to be done. >> there was no one to help his baby, but stewart hoped he could help someone else. he'd have to wait more than two

decades before he finally got that chance. >> if i wanted stuff, really irks sort of gave up all hope i was going to get that phone call. it came out of the blue, really, they said you were a match and if i was willing to go further than this, it had to happen like immediately. >> stewart went to london, for testing. they determined he was still a match. in november, 2012, he donated his stem cells, a six-hour process. stem cells are master cells found in bone marrow that have the potential to become any cell in the body. in this case, they can bolster the cells in the immune system. stewart was donating but he didn't know who he was donating for. >> it was quite a hard time. because i can't, i'm not one of these people to do something like that and not know what the outcome is. >> all they told him was an adult female in america needed it, urgently.

it turned out that stewart's match is celia hutchinson. in 2000, celia noticed a lump in her neck. that's when doctors diagnosed her with cll, chronic lymphocytic leukemia. >> it scared me because my parents died of cancer. my oldest brother has cancer and then after i was diagnosed i found out my youngest brother had cancer. it was very scary for me, but then i had to say, hey, it's going to be whatever it's going to be. >> i was glad i was able to be there all the time, you know, 14 years i missed an appointment because i had pneumonia. but i did drive her in and pick her up. you do what you got to do. if you care about someone, you do what you got to do. >> for 12 years, she endured repeated chemotherapy treatments. the cancer was forming

mutations, her doctors at massachusetts general hospital in boston recommended a more extreme option. a stem cell transplant. >> i wanted to live. i wanted life. i mean i felt i was too young not too try it to see what would happen to enjoy my life and enjoy my children and great grandchildren. i'm a great believer if it can be done, you go for it. >> in november, 2012, the american equivalent of the u.k.'s anthony nolan register called "be the match," notified celia she had a donor. a complete stranger that would turn out to be stewart, who is going to do nate stem cells for her t. transplant operation was a success. though not without complications. celia pulled through. but like stewart, she was left wondering about her donor. >> we didn't know where he came

from or anything. we thought we would alt least meet within the year. but it didn't work that way, because it was from the u.k.. >> the privacy laws are different for every country. for those two years, stewart waited anxiously for word on sellia. he only received bits and pieces of information over that time. until one day, a letter came near the end of 2014. >> i got the letter out of the blue to say your recipient wants to make contact with you. are you happy to shear your details? which we did and i always wanted to speak to her before christmas before the two years. we had an hour chat on the phone. >> it was absolutely fantastic. i just can't even express it. it was just the most exciting thing in my whole life to know that the donor has saved my life. >> i was checking my e-mails and i actually have an e-mail from celia that asked me to update her on how the interview goes today.

>> nearly every day since then, celia and stewart have been exchanging e-mails. but the ultimate goal was to meet this person so swort had an idea. >> i think she will be really shocked, in a nice way, i hope. >> he's coming from the u.k. to surprise celia.

>> do you know your brood type? there are actually eight different types. people with type o, they're considered the universal donors. that's the most requested type in hospitals. type ab positive are the

universal donors for plasma. it's most often used in emergencies for patients requiring massive transfusions. there are also forms of rare blood. that's the case in australia where the man with the golden arm has spent a lifetime of giving to save newborn babies from a blood disease. [ music playing ] on the surface james harrison is just an average guy. he loves his daughter and grandchildren. he collects stamps. he goes for walks near his noam home on australia's central keith. it's what's under the surface that makes jamie extraordinary. >> i got nicknamed the man with the golden arm. >> specifically, it's what's flowing in his vein, james' gold isen arm, his right arm, to be exact. he's donated blood every week for the fast 60 years. >> in 1951, i had just an operation which they removed a lung and i had the operation a

couple days after. my father was explaining what had happened in those days. they said my life has been saved and i am now able. he was a dad, himself. so i said, when i'm old enough, i will become a blood dofor. >> reporter: at that time you had to be 18 to do nate blood in australia. not long after, james became a donor, doctors called him with an idea. his blood they said could be the answer to a baffling problem in australia. >> in australia up until about 1967, there are literally thousands of babies dying each year and doctors didn't know why and it was awful, though women having numerous miscarriages, babies were being born with brain damage. researchers discovered and james was discovered to have this anti-body if his blood, which is amazing. >> it's a condition where a

pregnant's woman's blood attacks her unborn baby's blood cells. in the worst case, it can result in death or brain damage for babies. >> they have this anti-body. so it was quite revolutionary at the time. james has effectively helped babies in australia. but he's helped babies all around the world. >> james worked with doctors to develop a vaccine using the anti-bodies in his blood. a vaccine his own daughter even ended up needing. >> that resulted in my second grandson, he was born healthy. it makes you feel good, yourself, that you have saved a life here and you saved many more, that's great today we're making my 1001 do you nation. >> as he's done so many times before, james heads to donate

his plasma. he's a familiar face around here. no matter how many times he's given blood, there is one thing that will never change. >> never once have i watched it. i can't stand the sight of blood. i can't stand pain. >> dedofor center, james' plasma is separated from the red blood cells. he gets those back and the plasma heads off to become the vaccine. >> he comes in every week or two. he donates the plaids ma. his comboid reproduces the anti-bodies quickly. it's easy for him to do. he certainly doesn't see it as anything big. that's the other raush thing about james. he thinks his do nations are the same as anybody else's. he doesn't think he is remarkable. >> his blood is precious. in his home country, james is considered a national hero. but he doesn't see it that way. >> it becomes quite humbling

when they say oh, you have done this or you have done this, or are you a hero. no, no, no. it's something i can do. it's one of my talents, probably my only talent is i can be a blood donor. >> but it is a big deal, james and his vaccine are credited with saving the lives of more than 2 million babies according to australian red cross blood service. he has 2 million lives saved by one man's blood. >> every batch of anti--d that's ever been made in australia has come from james' blood, more than 17% of women in australia are at risk. so james has helped save a lot of lives. >> doctors still aren't exactly sure why james has this rare blood type. they think it may be from the transfusions he received at 14-year-old old after his lung surgery. he is only one of 50 people in australia known to have the anti-bodies, according to australia red cross blood service. >> i think james is

irreplaceable for us. i think we can't really underestimate what he's done. i don't think anyone will be able to do what he's done. certainly, we need people to step into his shoes. he will have to retire in the next couple of years. i guess that's the hope that there will be people who will donate. but we'll also have this anti-body and have life savers in the same way that he has. >> james is 78-years-old. in australia, you can donate blood until the age of 81. you can bank on him over the next few years without missing a beat. . another meeting, a world away. as stuart prepares to make the journey from england to america. two years ago, he donated stem cells to celia, a complete stranger in the united states, and they are about to meet for the very first time.

>> every two second someone in the united states needs blood. most frequently, those are for elderly patients. in low income countries, it's just the opposite. 65% of blood transfusions are given to children under the age of 5. 108 million blood donations are collected around the world, crossing borders along the way. it's a lot to keep track of. it's a network almost as impressive as the circulatory system, itself. it's a familiar scene and it happens all over the world. come to the blood donor center. register, wait, donate and you're done. but it's what happens next that makes the process of blood

donation so incredible. this blood bank is in copenhagen, denmark. of all the countries that report blood donations, denmark has the highest rate in europe. >> i think it has to do with culture and tradition. young people are grown up and taught about the meaning of giving blood. probably they have parents who are blood donors. we can see that. we have strong blood donors here in denmark as well. >> with all that blood, denmark has spent years perfecting its system. it's complicated to say the least. the journey of blood starts with the vein of a donor into a bag that's handed off to a courier who delivers it to the hospital's blood bank. here the blood is tested for diseases like hiv and hepatitis. it's also processed through a

centrifuge to separate the blood into its different parts. >> it's important to separate whole blood into blood components because we only need one component, the one patient, in that way you hope you live. >> three patients, one plasma, one platelet. one blood cell. it's important to separate these components because the red cells with going a a freezeer and the platelets are kept at room temperature. >> there's rare blood her as well. if the blood bank sedan doesn't have what a patient needs, that's where the real investigative work begins. >> we have three donors in our call of approximately 50,000 donors. we simply collect, storing, freezing the blood from those few donors, we can secure a

repository of these very rare blood groups. with i have a frozen repository here so we can always find the blood. >> one stranger saving another. it's what happened in celia hutchinson's case. in boston, she and her husband walter are back at massachusetts general hospital for a check-up. dr. chen performed celia's stem cell transplant two years ago. >> hi, how are you? walter, sellia great to see but same here. >> take some deep breasts. >> celia has been cancer-free for the past two years. the transplant did its job, celia credits her donor, stuart, with saving her life. >> i hear from my donor almost every day. >> really? >> yes. >> you have e-mail every day? >> yes, just about. >> everyone, including dr. chen, knows that stuart is actually down the hall from the exam room. everyone september celia.

he's come from england to surprise her. we tell celia we want to get shots of her and walter in the healing garden. the growing hospital staff want to see her being filmed. it's an easy sell. and celia has no idea what's about to happen. >> do you know who this the. >> oh my god. oh sclnl no i wasn't. i just texted you this morning. >> i know. >> you didn't. 40ud you get, i know you came by plane, oh fantastic. you knew about this? >> yes, i did. >> it was so hard to tell you for the past three weeks. >> some tears, lots of smiles and laughter, a match that

turned strangers into friends and family. >> well, she's a part of our family and i think we are hers as well. >> so it's nice to have more people that you can can't are a part of that. >> i have his dna. i have his blood. we're like brother and sister when you really think about it. so i mean, it was just remarkabl remarkable. >> i know he didn't feel like he did anything important and. sorry. i hope he realizes now what he dead for u-- did for us.

he's my hero. >> whether it's blood, bone marrow, stem cells, donating is a selfless act. a few minutes of time donating blood can mean a lifetime for someone in need. you never know who you might save or the difference you can make. for "vital signs," i'm dr. sanjay gupta.

donald trump dominating the gop race for the presidential tom nation like no other candidate. the new controversial comments to cnn about fox host megyn kelly that cost him a spot at the conservative conference today, has he gone too far? will they reenforce his image as a maverick unafraid to say what he thinks. i am poppy harlow in new york. you are watching cnn. we begin with this. a new day, a new controversy for donald trump, the republican presidential candidate and current front runner was axed from a