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00:00Infectious Diseases, the list of killers reads like a rogues' gallery, the dreaded
00:13Ebola virus, the worldwide killer AIDS, the much feared SARS, and the recent breakout
00:19known as avian flu, all threaten mankind.
00:26Women and women on the front line of medicine fight tirelessly for cures.
00:30But could the biggest clues actually lie in the past?
00:36Because there are some people who should have died from these diseases, but didn't.
00:41Can modern science unearth the secret of their survival in time to save future lives?
00:56The Black Death.
00:57Malaria.
00:58The Black Death.
00:59Malaria.
01:00The Black Death.
01:01Malaria.
01:02Tuberculosis.
01:03And the constantly evolving flu virus.
01:24Throughout history, infectious disease has been the planet's number one killer.
01:39Today, the threat is as great as ever.
01:42As world leaders brace themselves for the next disaster, some scientists are turning to
01:49the past in search of answers.
01:55Dr. Stephen O'Brien is a medical detective.
02:00This work is part of a global struggle to find new ways of fighting infectious diseases.
02:07Diseases that have the potential to kill millions.
02:15For Dr. O'Brien, the quest for cures is not just a professional one.
02:19For him, it's personal.
02:22AIDS killed his brother in 1994.
02:26Dr. Stephen O'Brien, Losing a brother to AIDS has clearly focused my concentration in
02:32seeing people struggling and reaching for hope.
02:37It sort of crystallizes your resolve to get to the end of the study and not worry about
02:45the details or the vagaries and the niceties of the process.
02:52Dr. O'Brien's come to believe that within our own DNA may lie the key to fighting the
02:59diseases which threaten us all.
03:01And he's made it his mission to find it.
03:03Dr. Stephen O'Brien, Losing a brother to AIDS,
03:04We might be able to discover natural hardwired defenses that scientists couldn't have thought
03:10of but which nature did.
03:12He believes that the place to look is among the survivors.
03:18People who have witnessed death and suffering on a scale we can barely imagine.
03:25Who came into contact with deadly infection, yet lived.
03:30Did they manage to pass on their immunity to their descendants?
03:35In the winter of 1665, the Great Plague swept through London, killing a third of its population.
03:44Dr. Stephen O'Brien, Losing a brother to AIDS,
03:46The effect of the plague was as devastating as a biological weapons attack would be on a modern city.
03:51And yet out of the devastation came super survivors.
03:56Men and women mysteriously resistant to this deadly disease.
04:05Dr. Stephen O'Brien, Losing a brother to AIDS,
04:06Why did they survive? Why didn't everybody die?
04:09Dr. Stephen O'Brien, Losing a brother to AIDS,
04:10Now through a series of ground breaking experiments and archeological discoveries,
04:14One man is hoping to find the answer.
04:18Do the descendants of the super survivors walk among us?
04:22And what can we learn from them?
04:25They would have maybe 15 or 20 doctors just literally staring at me and scratching their heads.
04:30Everyone I knew was sick and I wasn't sick.
04:33Does the Great Plague hold the key to surviving today's infectious diseases?
04:39O'Brien's quest will take him across continents and centuries.
04:48He believes that from these bleakest of times in history may come the brightest of hopes in the modern battle against disease.
04:56Dr. O'Brien thinks analysis of these times may just provide pivotal evidence.
05:02I can't think of an epidemic quite so devastating that we know about in history.
05:08Until you reach back to the Great Plague.
05:17December, 1664. London, England.
05:24A city on the verge of disaster.
05:32In the neighborhood of Suffolk, a clergyman named John Allen traveled to the home of the Phillips family.
05:37Mary Phillips had suddenly been taken ill.
05:44She had a fever. She was delirious.
05:49Alan was a physician as well as a priest.
05:55And one specific symptom made him very afraid.
05:58On Phillip's neck was a huge dark boil.
06:04A bubo.
06:05Alan prayed for her soul.
06:07For the people of the city and for himself.
06:11Because he knew the plague had returned to London.
06:17London.
06:18London physician and priest John Allen and those like him knew enough to be terrified.
06:24The effects of the plague had been documented for centuries.
06:26300 years earlier, the disease known as the Black Death had first swept through Europe, leaving as many as 30 million people dead.
06:35And it kept returning.
06:36There were waves of plague that ravaged Europe almost every generation up until the Great Plague of the 17th Century.
06:42Each time the symptoms were the same, fever and the mysterious black inflammations.
06:49Death occurred within a matter of days.
06:56By the mid-1600s, John Allen's city was once again under attack.
07:06In the winter of 1664 and the spring of 1665, London was a disaster waiting to happen.
07:31It's one of the largest cities in Europe, probably 400,000 people.
07:38There's a teeming mixture of all sorts of people, from the very, very wealthy, the aristocrats, the court,
07:44down to the marginal figures, the beggars, the vagabonds, the watermen transporting people over London.
07:51All of the waste disposal from those 400,000 people goes into the River Thames.
07:57Most of the water that that community drinks comes out of the River Thames.
08:01You can imagine the sort of cycles of infection and disease that are there as endemic all the time.
08:10Throughout the following year, Allen documented death on an extraordinary scale.
08:16Bills of mortality, weekly records of the dead, were nailed up in public places.
08:21In an average week, one might be expected to bury perhaps three to five people.
08:31In an average week in the plague period, you would be expected perhaps to bury 200, 300.
08:36In some of the suburban parishes, perhaps even 800 people a week.
08:40Now, that's a lot of dead bodies.
08:42Yet, in the midst of it all, a mystery.
08:47The plague killed many people, but it didn't kill them all.
08:53Some people emerged unscathed, despite living side by side with the dying.
09:00In their survival, medical detective Dr. Stephen O'Brien sees an extraordinary opportunity.
09:07But why did they survive? Why didn't everybody die?
09:12Why is it that two-thirds of the people in London survived?
09:20To stop an infection spreading, you have to understand how it spreads.
09:26Seventeenth-century physician John Allen saw hundreds of cases.
09:30Can modern scientists learn from the unflinching descriptions of men like him?
09:36Dr. O'Brien believes these accounts may hold vital clues.
09:41During the Great Plague, there were chroniclers of the infections that were describing in some detail
09:48the medical characteristics of the epidemic.
09:51And in many ways, today's scientists are really standing on the shoulders of these early observers,
09:57these medical giants, if you will.
10:01The raging thirst, the fever, the delirium.
10:06Most of all, the agonizing black swellings.
10:11Accounts of these symptoms allow today's scientists to put a name to this disease.
10:18The bubonic plague.
10:20It is a disease that is caused by a bacterium called Yersinia pestis that was discovered really in the late 19th century.
10:31The bacteria followed a complicated path.
10:35They are initially carried by infected rats.
10:39A flea bites a rat and picks up the bacteria.
10:43The flea then infects a human being.
10:46The plague bacteria are deposited into the victim's skin and move quickly to lymph glands nearby.
10:56The bacteria multiply and cause the glands to swell.
11:01They spread through the lymphatic system, eventually reaching the heart.
11:06At this point, they enter the bloodstream and are spread around the entire body.
11:15Vital organs shut down.
11:21And the patient dies.
11:24But the disease does not die with them.
11:31The bacteria want to multiply, so moments before the victim dies, the plague makes its final move.
11:38It finds a way to leap from human to human.
11:41Once bubonic plague became established in a very close community,
11:45a number of cases would develop pneumonia and cough up the organisms,
11:51and subsequent cases would pick that up as pneumonic plague.
11:55In other words, plague in the lungs.
11:57Now one person can affect another.
12:00And the mortality of pneumonic plague is greater than 90%.
12:04Its effect upon a population would be devastating.
12:07When pneumonic plague strikes a population, it should kill 9 out of every 10 people it infects.
12:20The death toll in London in 1665 was massive.
12:24It reached 150,000 people, a third of the population.
12:28But it should have been far, far higher.
12:31You would expect the disease to go on and on and on and devour that community.
12:38But it doesn't.
12:40This is the most enduring mystery of the great plague.
12:44How did so many people come into contact with one of the most deadly bacteria ever known?
12:50And survive?
13:01A chance discovery in London in the mid-1980s put the theory on trial.
13:10In the heart of the city, workers digging on the side of an old church uncovered 57 skeletons.
13:16They had been perfectly preserved by deep, heavy clay.
13:25These bodies had been dated to the time of the great plague.
13:31Each skeleton has been subjected to rigorous forensic examination to determine cause of death, age and social status.
13:52Were these victims rich?
13:54And did they in fact die of bubonic plague?
13:57This individual is a female, probably mid-30s to early 40s.
14:04There is no sign of actual pathological disease on the skeleton.
14:08So, up until the time of death, she was relatively healthy.
14:13The plague would have occurred far too quickly to actually make any visible sign on the skeleton.
14:19Evidence suggests that whatever killed these individuals was too swift to leave marks.
14:26It wasn't violence or prolonged illness.
14:30It took people of all ages.
14:33These clues point to plague.
14:36So, were these victims also members of London's underclass?
14:47A biological anthropologist can tell a lot about a person's social status from their bones.
14:54A tough life will leave its mark.
14:58The examiners looked for signs of deprivation, hard work and the traces of diseases associated with poverty.
15:05During that time period, it is possible to see diseases such as tuberculosis or syphilis.
15:12There's no indication of that on the skeleton at all.
15:15Other diseases that might be indicative of working class individuals is arthritis, which is not indicated on this particular skeleton.
15:22There are none of the signs you'd expect to see on the bones of someone who lived in poverty.
15:30And there's an even more compelling piece of evidence.
15:36The burial itself.
15:38If these were poor plague victims, they would most likely have been buried in mass graves.
15:43This person, based on where they were buried within the church, was not a poor individual.
15:51They were buried within the church in an individual grave.
15:54And that didn't occur among the poorer classes.
15:57They couldn't afford to do that.
15:58So this was certainly somebody that had some kind of social status at that time.
16:02All 57 skeletons found seem to belong to people from the upper classes.
16:12Their discovery, and others like it, call into question the argument that wealth was any real protection against bubonic plague.
16:19That argument that the poor are the greatest and really the only casualties of the plague epidemics, I think has shown to be flawed.
16:33I think every time an epidemic begins, people who watch it hope that it's going to be limited to a few individuals.
16:41With time, I think all of these diseases begin to show that they do not respect class, they do not respect social status, they do not respect ethnicity, they do not respect age, they simply spread whenever they get a chance.
16:56But if social class is not the answer, then what makes the difference between a victim and someone who survives?
17:04And can this centuries-old secret shed new light on today's deadliest threats?
17:09Why is it that two-thirds of the people in London have survived and two-thirds of the people in Europe survived?
17:26When people get infected with something like HIV, 95% of them die within 10 or 15 years.
17:32Just as we do today, the scientists of the plague era fought desperately to find a cure.
17:41At one point, John Allen genuinely believed he had found one, a potion based on a secret recipe.
17:49I myself have taken to drinking a vial of my elixir to ward off the evils of the pestilence.
17:57It has, thanks be to God, preserved me from the grave.
18:01Pioneers of medicine were simply tinkering around and trying to think of better ways to develop treatments or elixirs, if you will.
18:10Modern scientists have tended to write off the work of men like Allen as amateurish or superstitious.
18:21But is it possible that he was right?
18:25Could the medicines of the day be what made the difference between living and dying?
18:31Scientists never know what their research is going to provide, otherwise they wouldn't have to do it.
18:38And Allen was not alone. Hundreds of would-be healers proclaimed that they had found the answer.
18:48They offered their own potions, therapies and masks stuffed with spices that would allow the wearer to breathe bad air and emerge unscathed.
18:59Some of these treatments have evolved and have their modern equivalents.
19:02But scientists have spent years testing ancient medicines and agree that most would have afforded little protection against the plague.
19:15Allen himself knew this. He had learned the hard way.
19:19On the 15th of June, 1665, he lost one more of his patients. His own brother, Peter.
19:29I'm sure the plague approaches me, for it has pleased God to take from me the best friend I ever had in the world.
19:39It is my brother, Peter, who was abroad on Lord's Day last in the morning.
19:43Towards the evening, a little ill, then took something to sweat, which night brought a stiffness under his ear, where he had a swelling.
19:49He died Thursday last.
19:53Dr. Stephen O'Brien also lost someone close to him to infectious disease.
19:59His brother, Danny, died from an AIDS-related illness.
20:03He respects Allen's attempts to find an answer.
20:07I don't sneer at people who are trying to be creative and looking for novel solutions.
20:13But if it wasn't the elixir, what prevented Allen, who was exposed to hundreds of victims, from contracting the disease himself?
20:26One of the remarkable facts about Allen's love is that despite being intimately involved with the dead and the dying, he survived.
20:34Unlike many other doctors that he knew, he went on to live to a ripe old age of 64.
20:39He died in the mid-1670s.
20:42So there was something about him and others like him that meant he was resilient or immune.
20:49Dr. O'Brien has come to wonder whether men like Allen did carry the key to combating deadly diseases,
20:56not in the form of some miraculous potion, but within their own bodies.
21:01Did these people carry, unbeknownst to them, specific genetic endowments
21:06that they had been handed down from their ancestors that allowed them to defend a little bit better
21:12against that bacteria from that flea from that rat that had bit them and infected them?
21:18Did these people develop natural defenses that they passed on to their generations waiting for the next outbreak to come along?
21:27Science has shown that surviving the plague wasn't down to social class, or hygiene, or medicine.
21:34But could it have been directly related to genetics?
21:39Of the thousands of genes the survivors carried, was there one which could provide immunity to certain infections?
21:49And can Dr. Steven O'Brien and his colleagues find it?
21:53AIDS hit America's cities.
22:04Although our original and first detection of the AIDS illnesses was in the community of gay men,
22:14there was a second population that became infected at around the same time, but for a very different reason.
22:20And these were young boys who were born with the blood disease hemophilia.
22:29Hemophilia is a condition where the blood can't clot properly.
22:33Sufferers live under the constant threat of fatal internal bleeding.
22:36They rely on regular injections of a clotting agent called Factor VIII.
22:43In the 80s, this put them at particular risk from HIV, because Factor VIII was extracted from donated blood.
22:52And any one unit of Factor VIII could contain blood products from hundreds of donors.
22:59If just one of those people had HIV, then the entire batch was contaminated.
23:07The result was the accidental infection of a large number of hemophiliacs.
23:12The hemophiliacs were carrying a virus that was very deadly, killing 90% of the people that it infected.
23:22More deadly, if you will, than a bullet to the head.
23:25But as with the great plague in London, some people who should have died didn't.
23:30Bill Jameson is one such survivor.
23:35He saw firsthand what HIV-AIDS was doing to the people around him.
23:40It turned out that the products that we used to actually control our bleeding were actually the products that would turn out to kill most of us.
23:48Like every hemophiliac, Jameson was faced with a terrible dilemma.
23:51Take the Factor VIII and risk dying of AIDS, or don't take it and face the possibility of bleeding to death.
24:00What do you do? What do you do?
24:02I had a wife, I had kids, I had a business, I had responsibilities.
24:06So in order to provide for them, I decided to take that risk and continue to use that product.
24:12Jameson assumed that he would contract HIV and die.
24:16I would go in, they would have maybe 15 or 20 doctors just literally staring at me and scratching their heads, trying to figure out,
24:26this guy took this product, everybody else is positive, but you're as healthy as an ox.
24:32And that was the big question.
24:35The same question intrigued Dr. O'Brien.
24:38I wondered whether or not there was a difference in certain genes that allowed them to defend and clear the virus more efficiently than the individual who did become infected.
24:51He soon began what some called a fishing expedition, hunting out the one mutated gene in 25,000, which would make people like Bill Jameson resistant to AIDS.
25:03Most mutations, particularly when they occur inside of genes, are not very good for you.
25:12It's a little bit like taking a hammer to the engine of a Mercedes Benz and just whacking something.
25:19Well, most of the time you do damage.
25:22Maybe one time in a million you might do some good and make the car run a little bit better.
25:26It was two days before Thanksgiving in 1997 that I got a call from my treatment center and I said, Bill, you know, we found out why you never became HIV positive.
25:39I said, well, okay, you know, let's, let's find out what this big mystery is.
25:43As it turns out, Jameson had inherited a genetic mutation.
25:48They called it Delta 32.
25:50When HIV infects a normal cell, it does so by latching onto a protein called a receptor.
26:03This receptor is the virus's doorway into the cell.
26:08In Bill Jameson's case, the Delta 32 mutation means there is no receptor and no way for HIV to enter the cell.
26:16The infection is stopped in its tracks.
26:22After years of searching, had Dr. O'Brien and his colleagues finally found what they were looking for.
26:29When we first discovered CCR5 Delta 32, it was a whopper.
26:33It was basically the equivalent of pulling out a 300 pound marlin out of the sea on our fishing expedition
26:39because it caused complete resistance to HIV in all of the people who carry two copies of it, one from each parent.
26:47They now understood what the mutation was, that you inherited it from both parents and that it gave you immunity to HIV.
26:54But to help non-carriers, they wanted to harness the power of Delta 32.
27:01That meant understanding everything about it.
27:05Why did some people carry this mutation?
27:08Where did it come from?
27:11According to the theory of evolution, mutations are produced by mistakes in the genetic code.
27:17If they provide a positive benefit to the carrier, they survive into the next generation.
27:21So Delta 32 must have helped previous generations in some way, long before AIDS arrived on the scene.
27:30We were looking for some sort of breathtaking, cataclysmic event that basically wiped out millions of people.
27:41Millions of people, but differentially, according to whether or not they carried this gene.
27:48We thought it probably was an infectious disease of some sort, like HIV, but we knew it wasn't HIV AIDS because that disease has only been around for less than two generations.
28:03The answer, again, lies in the DNA.
28:07Because if you know how to read the genetic code, it will point to the time in the past when the mutation was most vital.
28:15When carriers survived and non-carriers didn't.
28:19The length of the segment around the Delta 32 is a surrogate, if you will, for time.
28:28So we examined that variation.
28:31We estimated the time elapsed since Delta 32 was last strongly favored.
28:37And that number came up to be 700 years, smack in the middle of the 14th century.
28:42This is a vital piece of evidence.
28:47Delta 32 had a significant impact in the middle of the 14th century.
28:52The time when bubonic plague, the Black Death, first struck the populations of Europe.
29:01The Black Death was probably the greatest epidemic in history.
29:05Something of the order of 25 to 30 million Europeans had died.
29:15Dr. O'Brien began to wonder if Delta 32 carriers were better equipped to survive bubonic plague.
29:22And that was when he connected another part of the puzzle.
29:26The last major outbreak of bubonic plague in Europe was the Great Plague of 1665.
29:31A much higher proportion of people seem to have survived that epidemic than survived earlier outbreaks of the disease.
29:40Is this evidence of the Delta 32 mutation at work?
29:46It could have been that the survivors of the Black Death passed down genes that protected their descendants from the Great Plague of the 17th century.
29:56If Dr. O'Brien is right, Delta 32 doesn't just confer immunity to AIDS.
30:03It could be even more powerful than that.
30:13In the centuries since the Great Plague, London has changed immeasurably.
30:16Because there's a lot of migration in human populations in and out of London, you're going to get other genes coming in and genes going out from the gene flow.
30:31Very few people in today's London can trace their ancestors back as far as the time of the Great Plague.
30:36And that is a major block to Dr. O'Brien's success.
30:41If he's going to demonstrate the power of Delta 32, he has to find a community where people can trace their ancestry right back.
30:49We were looking for a town which had been succumbed to the disease, but which had not really changed much in terms of immigration of people in and out.
31:03A time capsule, if you will, of the survivors of the actual event.
31:07And after years of searching, he found one.
31:14120 miles north of London, deep in the valleys of England's Peak District, lies the small village of Eme.
31:22Three centuries ago, the plague hit Eme and is still remembered today.
31:27It came on the 9th of August, 1665.
31:36To the south, Londoners were dying in their thousands.
31:40But so far, Eme had been spared.
31:45What the villagers didn't know was that a biological time bomb was about to be planted among them.
31:51A traveling salesman named George Vickers arrived from the capital.
31:54He had come to sell bales of cloth.
31:59Needing a bed for a few nights, he was welcomed into the home of the Cooper family.
32:05For days, everything seemed normal.
32:11Vickers went from house to house, selling cloth and tailoring clothes.
32:17But on the night of the 2nd of September, Mary Cooper heard her house guests screaming.
32:27Vickers had a fever.
32:30He was vomiting blood and bleeding from the nose.
32:33Five days later, he was dead.
32:37He was dead.
32:38And he was just the first.
32:44Ten days later, Mary Cooper's infant son died.
32:48The villagers realized what was happening.
32:52The parish priest called a meeting.
32:55As more and more people became sick, the healthy gathered together.
33:01They made a decision of tremendous courage.
33:05In the full knowledge that they might be sentencing themselves to death,
33:09they decided to place the village in quarantine.
33:11No one would try to run.
33:18No one would leave or enter Eme until the epidemic had run its course.
33:25In an incredible gesture of self-sacrifice,
33:30the population of Eme sealed off the village in order to stop the plague spreading further.
33:35So what we have is a very small, tightly-knit community,
33:40which remains a tightly-knit community to this day,
33:43where they were completely able to control people coming in and out of the village.
33:52For Dr. Stephen O'Brien, this event has huge scientific importance.
33:57While many small towns suffered the plague,
34:00the story of what Eme went through has been meticulously recorded.
34:05Not only that, but many of the people living there could trace their roots
34:09all the way back to the 1665 outbreak.
34:14For Dr. O'Brien's purposes, Eme is perfect.
34:20When I first learned about Eme,
34:22where most of the people that lived there
34:25were descended from the survivors directly,
34:28I became very fascinated with what I perceived as a scientific opportunity.
34:41Every year, the descendants of the plague survivors take part in a procession
34:45to keep alive the memory of their ancestors' bravery.
34:49Joan Plant is one of them.
34:52I first heard that we were related when we put together this family tree,
35:00and traced it back to Margaret Blackwell,
35:03who was a famous heroine, if you like, in the plague.
35:09Margaret Blackwell's story has become part of Eme's folklore.
35:13She had lost five members of her family when she herself fell ill.
35:22It is said that one day she staggered from her sick bed,
35:26entered the kitchen of her home,
35:28and either out of delirium, thinking it was water,
35:30or out of desperation, thinking it would end her life more quickly,
35:33she drank a jug of hot bacon fat.
35:39She vomited and collapsed.
35:44But then, somehow, she began to get well.
35:48She recovered.
35:50I asked Joan if she believed that the bacon fat
35:53had actually saved Margaret Blackwell,
35:55and she said she thought it probably did.
35:57And I told Joan I thought I had a different idea.
36:02Dr. O'Brien believes that Margaret Blackwell was one of the lucky ones,
36:06that she had inherited Delta 32 from both her parents,
36:10and it had saved her life.
36:12If he's right, if the mutation did save her and the other survivors,
36:17many of their descendants should carry it.
36:20Will O'Brien get his proof?
36:22Is the ability to fight off killer infections actually being handed down from generation to generation?
36:29And is it possible to harness this power in our own modern battle with infectious disease?
36:36The evidence is starting to point towards a genetic link between immunity to bubonic plague
36:44and immunity to the HIV virus.
36:48If Dr. O'Brien is right, a higher-than-average percentage of these people should carry the Delta 32 mutation.
36:59His plan is to take and analyze samples of their DNA.
37:04And then we take this back to the laboratory where DNA is extracted that is suitable for analysis of any genes we might be interested in,
37:14or you might give us permission to test.
37:22The DNA of each volunteer is analyzed for the presence of Delta 32.
37:28The results seem to confirm Dr. O'Brien's theory.
37:31We ran yesterday looking for Delta 32 in that sample we collected from EM.
37:37We actually collected something like 85 individuals to see who had Delta 32, who had two copies, who had one copy.
37:46And when we genotyped them, we discovered about 15% of them were Delta 32 from EM,
37:53which is about 50% higher than the surrounding regions around EM, which had not had the same history of plague.
38:04So that was exciting, and the number of people that had two copies was twice as high as we expected.
38:12Although the evidence so far suggests that Delta 32 carriers are immune to bubonic plague,
38:17O'Brien needs proof.
38:20He's about to perform the test all his research has been leading up to.
38:25Under laboratory conditions, the cells have been exposed to the plague bacteria, Yersinia pestis.
38:32And the results are extraordinary.
38:35Delta 32 does appear to offer immunity.
38:38If you take normal cells that have the normal parent molecule of Delta 32, a gene we called CCR5,
38:48they do take up your Sinia pestis quite rapidly.
38:53If you take cells which have the equivalent of Delta 32, they're resistant to your Sinia pestis.
39:00They do not take it up.
39:02After years of research, Dr. Stephen O'Brien and his colleagues finally appear to have their answer.
39:08Delta 32 really does seem to be an almost miraculous mutation.
39:14It protected people from bubonic plague for centuries in Europe.
39:18And carried by their descendants, it has also helped defend against the modern plague of HIV AIDS.
39:25Now that scientists understand how Delta 32 works and where it comes from,
39:30they are beginning to learn how to mimic its effects.
39:33So if we could discover why patient A fights off AIDS or Ebola or SARS or bird flu and patient B doesn't,
39:48then we could imitate the process by developing new pills or therapies or drugs
39:55that we can give to the patient who wasn't lucky enough to be born with them.
39:58This new generation of medicines is already being tested.
40:04Spike Rhodes has been HIV positive for 20 years.
40:08He was close to death when he was given the chance to try the first in a new class of drugs called fusion inhibitors.
40:14Just like Delta 32, they stopped the virus by blocking the portal through which it enters cells.
40:23For Spike, the results have been extremely encouraging.
40:27The T cells which support his immune system began to recover within weeks of first taking the drug.
40:34My T cell counts doubled and my viral load had gone undetectable, which was also quite a surprise.
40:44And within the next three months after that, my viral load stayed undetectable.
40:50My T cells had doubled up again.
40:52If it hadn't come into my life, I probably wouldn't be here.
40:55AIDS, SARS, leukemia, prostate cancer, breast cancer, Alzheimer's, Parkinson's, the litany of diseases that fill our hospitals.
41:09Discovering how these defenses work explicitly, pinpointing the exact gene, giving us a mechanism.
41:17Well, then we know what to go after.
41:20Then we know how to develop treatments that are effective and clear out these hospitals from these chronic diseases that we cannot treat.
41:30We are in the middle of a scientific revolution that could change the way we treat sickness.
41:37It's a revolution that began in death and suffering centuries ago.
41:41And as threats continue to emerge from all corners of the biological world,
41:48it may be the mysteries and miracles of the human body itself that provide our ultimate line of defense.