PBS Secrets of the Dead: Killer Flu
Dr. Jeffery K. Taubenberger and Kurt Tondorf
Chief Molecular Pathologist, Armed Forces Institute of Pathology and Supervising Producer
Thursday, March 04, 2004; 1:00 p.m ET
In 1918, a flu pandemic spread so quickly that by the end of the following year, an estimated 40 million people were dead. Where did this particular flu strain come from, and what made it so deadly? PBS Secrets of the Dead: Killer Flu explores the genetic research of the 1918 flu strain and how it relates to the present-day virus.
Dr. Jeffery K. Taubenberger, chief molecular pathologist at the Armed Forces Institute of Pathology, and supervising producer Kurt Tondorf will be online Thursday, March 4 at 1 p.m. ET to discuss flu strains and the documentary
Submit your questions and comments before or during the discussion.
Dr. Taubenberger and a team of scientists are involved in studying the DNA of this World War I pandemic virus in the hopes of stopping a genetically similar flu before it strikes again.
Tondorf joined Thirteen in November of 2002 as an associate producer in the station's science programming unit and has since become coordinating producer for Secrets of the Dead. After overseeing post-production for last season's Secrets of the Dead finale, "Bombing Nazi Dams" (winner of a New York Festivals Gold World medal), he went on to serve as producer of the U.S. version of "Warrior Challenge," a four-part series that aired nationally on PBS in May 2003.
Editor's Note: washingtonpost.com moderators retain editorial control
over Live Online discussions and choose the most relevant questions for guests and hosts; guests and hosts can decline to answer questions.
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Hello, and thanks for joining us today. Dr. Taubenberger and I are here to answer any questions you might have about last night's program (which will actually air nationally again tonight for satellite viewers). Fire away. -KT
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Forked River, N.J.:
For Mr. Tondorf:
I've seen a couple of the Secrets of the Dead programs and am always struck by how interesting the stories from obscure individuals can be. Where do you find your interview subjects? Where do the stories come from?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: We have a host of talented producers who pitch us story ideas from all across the globe. We often have to be very selective. Most of the stories are gleaned from newspapers and magazines, and every so often a producer will just happen upon a story by random chance (by word-of-mouth, etc.). Thanks for watching.
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Chicago Ill.:
Please clarify: Do I understand correctly that the flu virus originates in birds and cannot be transmitted to humans without the "cooking pot" of the pig. But, the pig is a mammal the same as humans. So I don't understand why it cannot be transmitted directly from bird to human mammal. And, can we absorb this virus by eating the meat of both the bird and the mammal?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Influenza A viruses are generally thought of as deriving as viruses from waterbirds like ducks and geese. It is still not completely clear how bird viruses adapt and mutate into forms that can infect mammals like horse, pigs, and people. Pigs are known to be susceptible to both human and bird flu viruses so they have been thought of as "mixing vessels." But no real evidence exists for this process to form human pandemics. The H5 viruses in Asia have shown that humans can be infected directly with bird flu viruses, so I don't think that pigs would be needed in this process.
You can't get the flu from meat.
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Brooklyn, N.Y.:
Dr Taubenberger and Kurt - How do you personally prevent catching a cold?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: "colds" are caused by a variety of different viruses. In general respiratory viruses are spread by aerosol droplets. So, washing your hands, avoiding touching your nose and mouth, avoiding clsoe contact with others who have "colds." In terms of influenza, I recommend taking the vaccine.
J.T.
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Pauline, S.C.:
If by some mistake, the 1918 flu strain were released into our society today, do you think the result would be as devastating as it was in 1918?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: I think Dr. Taubenberger says in the opening of the film that there is a worry that mass transit will allow such a virus to jump more easily from continent to continent. Then again, our awareness and surveillance of such a virus is much higher now than it was in 1918. -KT
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Waldorf, Md.:
I've read several books about the 1918 flu (Gina
Kulata, Alfred Crosby) and just read the PBS
Internet material on your show, and theories
about the flu jumoing (or not jumping) species
and the notion of the flu infecting people for
several weeks without showing symptoms, and
then mutating into the serious, deadly strain. In
the case of the 1918 flue, there was an early,
relatively mild outbreak during the summer, and
then a "second wave" of the much more deadly
strain in Sept. and October. Can anyone account
for this? Is it possible that the flu in the first wave
mutated into the deadlier version and "caused"
the second wave? (Since the thinking now is that
the flu did NOT begin with birds, you say you are
looking for a different host. Could that host --at
least of the second wave -- have been humans?)
Keep up the good work! (Both in the lab and on
the air.)
Dr. Jeffery K. Taubenberger and Kurt Tondorf: This is a very inportant question. Since flu viruses were not known to exist in 1918, no isolates were made. Because the initial wave caused illness more than death, far fewer autopsies are available than from the fall wave. We are limited to finding genetic material from the virus from autopsy tissues.
It seesm likely to me that the first wave strain did acquire a mutation that made it spread much more efficiently in people. The difference therefore might not be in virulence per se, but in how well it spread from person to person. We are trying to find a spring-smmer wave case to test these theories.
JT
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Minneapolis, Minn.:
I have heard that the flu started in the United States in the spring of 1918 at a military base in the state of Kansas. Have you heard of that and what is your response? Also if this is a case of the flu of 1918 why did it occor in the United Sates when the United States had not yet sent troops to England?
Now just my comment about 1918, isn't pecular that so many strange things happened in 1918 that changed the world and has all but been forgotten. Such as the world war and the flu.
Thank you Robert from Minneapolis, MN USA go Twins!!!!
Dr. Jeffery K. Taubenberger and Kurt Tondorf: One of the possible origins for the 1918 virus is Camp Funston, a military camp in Kansas, and we explore this in the opening of our film. Within a week of the first case being announced there in March 1918, 500 people fell ill. But as Dr. Taubenberger will attest, the precise origin of the virus has still yet to be confirmed, and perhaps never will be. There is still the possibility that the 1918 virus began with a 'herald wave' that struck earlier than 1918. --KT
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McDonough, Ga.:
My grandfather died of the Spanish Influenza at forty years of age. He lived in the same house as my grandmother, father and two other children. My grandmother nursed him and took care of her children. How is it no one else in the house contacted this flu?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: This is difficult to answer but is typical of influenza infection in general. In 1918 at the height of the outbreak only 28% of the population became ill with flu. Later studies showed however that nearly 100% of the population was exposed to the virus since they had antibodies in their blood against it. Why 2/3 of people get exposed to a virus, even the 1918 flu, and not have any illness is not clear, but their are probably host response differences.
JKT
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Muscle Shoals, Ala.:
Dr.Taubenberger,
How similar is the genetic structure of the 1918 influenza strain to the current H5N1 avian strain currently circulating in Asia? Do you think that a precurser strain of avian flu was circulating in birds in the years imediately prior to the 1918 outbreak?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Both 1918 flu and current Asian H5N1 viruses are influenza type A viruses, sharing a similar genetic structure overall. Subtle changes in the genes of these viruses probably result in their ability to infect different species of animals and to cause different levels of disease. Understanding these genetic changes between bird and human strains is a key component of my lab's work.
I think the 1918 flu originated from an animal but not from the typical ducks that have been known to carry flu. I favor an unknown avian host.
JT
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Portland, Ore.:
How is the flu spread from one location to another? How are outbreaks able to show up in remote areas simultaneously with no obvious human carrier between them? Air travel cannot be to blame because this seems to have occurred prior to this mode of transportation.
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Flu actually originated as a bird virus millions of years ago. As we mention in our film, typically the virus crosses the species barrier into mammals, like pigs, before infecting humans. So birds can actually bring the virus to populations otherwise untouched by the disease. -KT
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Bronx, N.Y.:
Could you explpain how long does flu virus stay in one's body?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Flu infection is very rapid. You generally get sick with 12-24 hours after exposure, and peak viral replication is 24-48 hrs. Very little virus is left in the respiratory tree after 5-6 days.
JT
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Basking Ridge, NJ:
For the producers,
Why wasn't there more about the bird flu in this program? Does it take a long lead time to get a show on the air?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Great question, and I'm glad it was asked. This film was first conceived over a year ago. With such a fresh topic (and with scientists like Dr. Taubenberger continually updating their research!) we found it daunting to include everything we would have liked to. The bird flu started becoming a world news story right around the time we were wrapping up our production. I'm sure there's another producer somewhere working on a film about that story. --KT
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San Diego, Calif.:
What would be the casualties counts of the same 1918 flu in our modern time?
Did you run any model factoring major differences between now and then (Hygiene, information, healthcare,etc.)?
Thank you.
Dr. Jeffery K. Taubenberger and Kurt Tondorf: This is a difficult question. On the plus side, we have the ability to make protective vaccines, have excellent anti-influenza drugs, and antibiotics for secondary bacterial infections. On the down side the world is more crowded and movement of people by airplane around the world would likely make a pandemic strain spread even more rapidly than in 1918. Also most of the world's population lives in areas without the access to vaccines and anti-viral drugs that are available in the U.S. and other industrialized nations.
JT
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Arlington, Va.:
In relative terms, how dangerous was the Swine Flu (from the '70's). Could that strain have mutated, and we dodged a bullet?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Potentially all human exposures to animal flu viruses have the risk of becoming serious health threats. Flu viruses have to adapt to their host to be transmitted from person to person. Without that, the virus cannot spread in humans. That was the case in the 1976 swine flu outbreak in NJ and more recently in the Asian H5 flu outbreaks. It is important to try to control these animal to human trnasmissions to reduce the risk that these viruses could mutate into a human-adaptive form. Luckily for us, the chance for this happening seems to be very small (since pandemic viruses only appear rarely) but the risk is NOT zero.
JT
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Washington, D.C.:
We've seen some pretty bad flu epidemics since 1918, but nothing as bad. What's changed, besides better vaccines, to lessen the chance of another epidemic on this scale?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: I think a big part of why the 1918 influenza virus killed so many millions of people was because at the time, viruses weren't widely recognized as disease-causing agents. The medical community in 1918 suspected the deaths were being caused by a bacterium. Another potential factor was the fact that this incredibly virulent virus struck the world at a time when a major war, involving many of the most populous nations in the world, was still raging. Today, there's still the possibility of millions dying from a particularly virulent strain of influenza, but the surveillance mechanisms in place will likely stop a death toll short of such catastrophic numbers.
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Marietta, Ohio:
Hello Dr. Taubenberger,
I have done some historical research into the 1918 pandemic using public health records in Piqua, Ohio. Are you aware of any projects which are compliling data on how the influenza epidemic impacted smaller communities in the United States? Also, what would be the 'common' names of the time for the various secondary infections that caused mortality in 1918 flu victims?
Thank you, I enjoyed the program last night!
Rachel
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Yes, there are people investigating the outbreak in various communities in the U.S. You might want to start with the Crosby book - "America's forgotten pandemic" as a good source.
Common names were: influenza, flu, grippe, grip, pneumonia. The bacteria casing secondary infections were often identifed as "Pfeiffer's bacillus" but also identified were strep and staph infections.
JT
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Washington, D.C.:
Hi Mr Tondorf,
What's next for SECRETS? Any shows coming up?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: On April 7, just in time for Easter, we are airing a show on the Shroud of Turin ("Secrets of the Dead: Shroud of Christ?") that offers evidence that the relic can in fact be dated to the time of Christ. We also have a D-Day special coming up that we're quite excited about ("Secrets of the Dead: D-Day" -- airing May 19) that takes a look at the engineers, inventors and soldiers that made the largest invasion in the history of war such a success. Hope you'll all watch! --KT
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New York, N.Y.:
I would like to know your views on the flu virus in regards to livestock such as the bird flu epidemic in Asia. How does that compare to human flu?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Influenza A viruses are present in wild birds like ducks, geese, terns, gulls, etc., and have also been found in domestic birds: chickens, turkeys, quail, and domestic mammals like pigs and horses. In the case of domestic animals all of these animals are susceptible to significant flu outbreaks if an animal-adapted strain gets into a population. This can have devastating consequences for farms around the world, like the recent Asain flu outbreaks in chickens. The bigger risk to humans is that one of these animal flu viruses can adapt by mutation or reassortment with a human influenza strain and cause the emergence of a new pandemic strain. This is another important reason to control the spread of these outbreaks like was done in Europe last year and is being attempted in Asai currently.
JT
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Anonymous:
Mr. Tondorf:
How do you decide how much airtime to give to different viewpoints? For instance, its my understanding that the Etaples-theory is a real outlier among flu experts. Do you ever worry about misleading viewers into believing that high speculative theories are true.
Dr. Jeffery K. Taubenberger and Kurt Tondorf: As producers for PBS, we always strive for parity. Much like with political debates, you try to give equal time to differing viewpoints. I think we did a good job in this film in letting Dr. Oxford follow his Etaples theory and draw his conclusions before countering his viewpoint with Dr. Taubenberger's, which is that we can't be sure where this virus got its start, but what we *can* do is try to determine why it was so virulent. --KT
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Ann Arbor, Mich.:
It is of course not uncommon to find that a
confounding epidemiologic situation is
best explained by not a unique display by
a single and common virus but, rather, an
unsuspected interplay of two different
microbes -- one obvious, one not.
Is there any suggestion -- clinical,
experimental or epidemiologic -- that
such may have been the case in the 1918
pandemic?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Everything we know about the 1918 flu (epidemiology, spread, the way it caused illness, and the pathology of those dying are all compatible with it being an influenza virus outbreak. That said, a number of investigators have wondered about a ossible bacterial contribution to the virulence in 1918. Arguing against that is that many different bacteria caused secondary pneumonias in 1918 at different itmes in different places, but the flu virus was constant.
JT
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Brooklyn NY:
Mr Tondorf: Did you start production on this program before the US outbreak of the avian flu? Does your team look for issues in the news to explore on SECRETS OF THE DEAD?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Granada, the London independent that produced the film for us at Thirteen/WNET New York, actually began production on this film over a year ago, so we didn't get a chance to incorporate the story of the avian flu. Influenza as a topic is constantly changing; it's not an easy one to make a film about, because chances are, you're going to read something in the newspaper the day after your production cycle comes to a close that you'd have loved to include in the film. But that's not a complaint -- it's a great thing that people like Dr. Taubenberger are continuing to study this virus in an attempt to solve all of its mysteries, and that such efforts are making news. --KT
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Merrick, NY:
How many strains of the flu are there and are some more dangerous than others?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: There are hundreds of known influenza A subtypes, reflecting thousands of different strains in all sorts of animal hosts (birds and mammals). Only three flu strains are known to have caused human pandemics in the last 100 years (H1N1 in 1918, H2N2 in 1957, H3N2 in 1968), and small isolated human exposures have occured to other bird flu strains in Asia and Europe in the last few years. The dangerous strains are the ones that acquire mutations that would allow them to move between species, and most dangerous are those that acquire the ability to infect humans. Future pandemic strains are likely to derive from animal viruses that adapt to humans. We can't predict yet which strains are more likely to do this, but of couse much concern has been raised by the continued spread of H5N1 viruses in Asia.
JT
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Mt. Lebanon, Pa.:
How did scientific medical "experts" in 1918 explain away this flu to the public and to themselves when the discovery of the neutron and the invention of the electron microscope were still 12-20 years away?
If you can't see it or predict its behavior from analyzing its tracks, you obviously can't combat it. Except through blind luck or wishful thinking.
Thanks much. Registered Electrical Engineer
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Reports are that the medical community was completely overwhelmed by the 1918 flu. Scientists and doctors of the day had thought they were making important strides in combating infectious diseases, but they were completely unprepared. They had still not isolated viruses by this time. As for how they explained it away, I'm not quite sure. I do know that the headlines of the day, which we poured over in researching this film, were primarily dominated by the war. Between war and the flu, the world's population had essentially been forced to grow accustomed to living with death. As Dr. Oxford says in our film, "They just took it." --KT
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Washington, D.C.:
I heard once that the 1918 flu was a military-cultivated strain that tested quite well in horses. So well, in fact, that the experiment was immediately stopped and all the horse carcasses burned. That made the virus airborne, and the smoke drifted into the nearby camp. Targeting a horse for a flu virus in 1918 would have immobilized any army.
How frequently do health officials encounter flus that spread quickly and have serious long term health consequences to the victims, such as SARS?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: I know of no data to support a link to horses and the 1918 flu. We know that pigs were infected simulataneously with humans in the U.S. in 1918. We also know now that there are horse influenza strains. But again, no historical data I'm aware of links the emergence of the 1918 flu in humans to flu outbreaks in horses.
Flu viruses were not known to exist in 1918, so no strains could be identified or passaged in animals.
As to the identification of newly emerging viruses, this is happening with some frequency: Asian flu outbreak, SARS, Nipah viruses in pigs and people in Malasia, etc. As the world's population expands, becomes more mobile, and as changes to agricultural practices and cultivation of unpopulated areas continues, the chance for novel viruses to move from the wild into farm animals and people increases.
JT
JT
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Reston, Va.:
I heard somewhere that taking medicine to stop a fever is actually bad when you have the flu. That one should let the fever kill off the virus. Is this true?
Thanks
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Fever is a component of the body's response to infection, however, high fever can be very dangerous and it is advisable to treat them.
JT
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San Francisco, Calif.:
How is the SARS and Asian flu differ from
the Spanish Flu?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: SARS, a coronavirus, is actually from a different class of viruses than is influenza, though both are target the human respiratory tract. The avian (Asian) flu that we're all reading about in the news is transmittable from bird to human, but *not* from human to human, as was the 1918 (Spanish) flu. --KT
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Severna Park, Md.:
My father was born in the Blue Ridge mountains of Virginia in 1921 and he told me of entire mountain families dying of the 1918 flu when he was a toddler. Can this be true?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: In general, the mortality of the 1918 flu was about 2.5% of those made ill by it. About 28% of the population had clincal influenza in 1918, so the total death rate in the population would be about 0.7%. There were however isolated populations lacking medical care that had much higher mortality. In some Inuit villages in Alaska, there were outbreaks with an over 70% mortality rate. It is possible that some of these isolated communities had much higher mortality.
JT
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Plano, Texas:
I'm a high school biology teacher -- wondering how I can get a copy of this film to use as part of my lessons. It would be an excellent teaching tool!
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Thanks for your interest! "Secrets of the Dead: Killer Flu" is available direct from Shop PBS (1-800-336-1917). I should also tell you to check out our web page, where there is a lesson plan for teachers (http://www.pbs.org/secrets). --KT
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College Station, Tex.:
How do you know that there was only one virus involved? If we assume that this flu virus was in the whole population and that those most likely to die are those of the average soldier's age, then if we assume that the soldiers additionally caught an additional virus and passed it on to each other and women of their own age group, ie their dates, might we assume that the imune system response to one virus allowed the other virus to kill?
Roger
Dr. Jeffery K. Taubenberger and Kurt Tondorf: All the evidence points to a single cause, the 1918 H1N1 flu strain. Most deaths were however caused by secondary bacterial infections of the flu-damaged lungs in the absence of antibiotics. The age-distribution of mortality was high in 18-35 year olds all over the world, not just the soldiers of Europe and the U.S. and looks like an unusual response to this virus. Explaining the young adult mortality is key to understanding the whole outbreak.
JT
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Winthrop, Mass.:
How hard is it to cultivate flu from a dead body? Could a body from the pass flu plague be dug up or unfrozen and the flu virus extracted from it?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: The flu virus in the autopsy material and in the frozen material is no longer viable and can't be cultured. We have been able to extract tiny genetic fragments of the virus from these tissues. Other scientists have reported isolating DNA fragments of the plague bacillus from bones and teeth of plague victims from the 1700 hundreds.
JT
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Annapolis, Md.:
Kurt
I'm a big fan of Secrets of the Dead. When can we expect to see the next one after Killer Flu?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: Our next broadcast, "Secrets of the Dead: Shroud of Christ?", is scheduled for Wednesday, April 7 at 8pm on PBS (check local listings). It's a scientific look at the Shroud of Turin and the new evidence that suggests this Christian relic can in fact be traced back to the time of Christ. --KT
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San Diego, Calif.:
Kurt-- What got PBS interested in this topic?
Dr. Jeffery K. Taubenberger and Kurt Tondorf: It's probably safe to say influenza is a disease everyone knows a bit about. But the fact that influenza can be such a widespread, catastrophic disease -- as it was in 1918 -- is little known. The origin and virulence of an 86-year-old virus is still puzzling to modern scientists, and we wanted to explore why. As with all our Secrets of the Dead programs, we were interested in digging deeper into a relatively unknown topic. --KT
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Dr. Jeffery K. Taubenberger and Kurt Tondorf: Dr. Taubenberger and I would like to thank everyone who took time to watch the show and ask questions today. For more info about the program, click on over to our Secrets of the Dead web site (http://www.pbs.org/secrets). Hope you'll stay tuned for the upcoming Secrets of the Dead episode "Shroud of Christ?" which premieres April 7 at 8pm on PBS. --KT
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