D.A. Henderson and Ken Alibek
Chat on the Threat of Smallpox as a Weapon with Drs. D.A. Henderson and Ken Alibek
March 21, 2000
On Thursday, March 16, 2000, "CNN Newsstand" examined the claims of a Russian researcher and author, who found that the Smallpox virus could be used as a biological weapon. As well as examining the possible use of smallpox in warfare and U.S. preparedness in an attack, Newsstand explored the history of the virus and eradication of the disease.
After the program aired, a special chat took place on to discuss the Newsstand piece. Two experts in the field, Dr. D.A. Henderson, Director, Center for Civilian Biodefense, Johns Hopkins University, and Dr. Ken Alibek, author of "Biohazard," and Chief Scientist at Hadron Incorporated, a company specializing research programs in biological weapons defense; in treatment and prophylaxis of infectious diseases; and analytical research in industrial biotechnology and microbiology, joined the chat via telephone. CNN.com provided a typist. The following is an edited transcript of that chat.
Chat Moderator: Dr. D.A. Henderson and Dr. Ken Alibek are joining us tonight to discuss and answer your questions about the potential use of the smallpox virus in biological warfare. Welcome, Drs. D.A. Henderson and Ken Alibek.
Dr. Ken Alibek: Hello.
Dr. D.A. Henderson: Hello to you all.
Chat Moderator: Why is smallpox a more serious threat than other forms of biological warfare?
Dr. D.A. Henderson: The smallpox death rate is about 30 percent. That is three out of 10 will die of the disease. There is no treatment. Beyond that, the disease will spread. If we begin with 50 cases, two weeks later, we will probably have on the order of 1000 cases. And then two weeks later, there will be another multiple of that. This is what is particularly disturbing about smallpox.
Dr. Ken Alibek: D.A. is correct. It is a very contagious infection. It is easy to produce, relatively easy. And a quite small amount of this weapon can produce a devastating effect.
Question from Worried: What preventive measures are being taken in the U.S. and around the world to prevent an outbreak?
Dr. D.A. Henderson: At this time the most important thing we could have would be an adequate supply of small pox vaccine.
Dr. Ken Alibek: I agree with Dr Henderson. In my opinion, we need a new program to develop some new prophylactic approaches. The disease is very interesting from a pathogenesis standpoint.
This virus is produced when it disseminates in a body. It produces a large number of peptides. Then it makes immunity peptides. It helps the virus overcome the immune system. We need to study this infection more thoroughly. We need more knowledge about immune responses about smallpox. And probably it will help us to develop new therapeutical approaches to fight this infection.
Dr. D.A. Henderson: I think what Ken is saying is that today we have very little that we can do to help a patient once he is infected.
Dr. Ken Alibek: I agree.
Dr. D.A. Henderson: We need to have, for the short term, enough vaccine to at least stop an epidemic before it gets out of hand.
Dr. Ken Alibek: I agree with this idea. I am not against producing this vaccine in needed amounts. We donít have to stop research to study this infection. In the future it will be possible to develop new treatment.
Question from Drociuk: I have a question. Do you feel that increasing the surveillance of ID in general is valuable, or is a more symptom-based system better?
Dr. D.A. Henderson: I think the most important thing we can do at this point is to have a much better system for detection of all types of disease, and to have our physicians who are doing treatment of patients in close contact with our public health people. So when they see a strange disease that they sound an alarm, permitting other people, who have special competence, to come in and take action.
Question from Tim: How many people would die in the first two weeks after an attack?
Dr. Ken Alibek: In my opinion, it is not a correct question. The most important is that what is the amount of biological weapon that is used? What were the weather conditions, the terrain conditions, and the population of the area?
Generally, one medium-range bomber with two tanks, two-ton capacity each, is able to cover 1000 sq. kilometers. It is much bigger territory than New York City and surrounding area. And if this weapon is primary aerosol, it could cause hundreds of thousands of infections in the first couple days.
The incubation period is three to 14 days. We can assume that the number of people in New York or Los Angeles would be hundreds of thousands, or even millions of people.
Dr. D.A. Henderson: To add to this, we have to look at the situation in a different way. Suppose that only a small amount of the virus is released that affects only 50 people. What would happen if only 50 were infected is that there would be serious troubles in trying to find suitable hospital beds to house them, because this would require special rooms, which are under negative pressure. Hospitals have very few of these rooms.
Then you would have many people immediately requiring vaccinations: contacts with the patients at school, workers at the hospital, their families. The numbers would immediately be quite large. By the time we would diagnose the cases, the disease would have already spread. And there would be a thousand or more people feeling perfectly well, but incubating the disease.
And if you begin to look at this in terms of practically how we would control an outbreak, we would very soon be in deep trouble without sufficient vaccine. More than this, one can assume that the people in the city who are affected are going to be very concerned. And one can imagine chaos in a city as a result of this. In brief, even 50 cases would be a problem of major proportions.
Question from RecilS: What is the incubation and reproduction rate of smallpox? How fast can it move through a host?
Dr. Ken Alibek: Officially, what we know and what we see in books and manuals, we see incubation between seven to 14 days. Unfortunately, what we noticed after observing in the Soviet Union that it could be shortened if a concentration of agent is quite high, in some cases, as short as two or three days after infection.
The next person who is infected would have the regular incubation period from seven to 14 days. But the primary people could have a short incubation period.
Dr. D.A. Henderson: The question was "how rapidly." That is, how many cases would occur from exposure? This depends on the season. If it is cold or dry, it will spread more rapidly. If we had a release at this time in a cold cooler dry climate, and with so very few people vaccinated, one could imagine that the reproduction rate would be at least 15 to one or 20 to one. That would be conservative.
Dr. Ken Alibek: Yes, a chain reaction, geometric progression.
Question from Tomohiko: Are there any plans of increasing the stock of vaccines?
Question from Sean: How long is a vaccination considered good for?
Dr. D.A. Henderson: A request for proposals for production has been released by the Center for Disease Control, asking for bids for producing 40 million doses of vaccine.
I think, eventually, we will want to have between 100 million and 135 million doses. What is important is that this vaccine, when properly stored, will be fully potent for at least 25 years, probably 100 years. So that this is a wonderful insurance policy, which we should have.
Dr. Ken Alibek: I agree with what D.A. is saying. The vaccine would contain the epidemic. In early stage, the vaccine could be a treatment for early cases of this infection. But we need to take care of those who are diseased. The vaccine is not a good treatment. We don't have to stop researching. Not specifically small pox, but there is a large group of smallpox type viruses. We need to study them, and develop proper treatment against pox- virus infections.
Dr. D.A. Henderson: He also asked about the duration of protection. Here our data are not very accurate. We believe that after a single dose of vaccine the protection is very good for at least five years. But then it begins to wane. And it becomes progressively less protective as time goes on.
How many people are protected at this time, who were vaccinated in the U.S. before í72, is a question we really can't answer. For those who have had two or three successful vaccinations, I suspect that they are moderately protected.
For those with one, I would be surprised if they had very much protection at all. Over all, I suspect that for our entire population we probably have something on the order of 75 percent of the population today susceptible to smallpox infection.
Question from Sanatio: Is the smallpox vaccine currently available to the general public? If yes, where can I go to be inoculated?
Dr. D.A. Henderson: There is no vaccine available for the general public. There are stocks of vaccine, which are retained on reserve in case we need them. But at this time we would not recommend that individuals be vaccinated because there is a risk of having serious reactions following vaccination.
If the risk of a small pox attack were to rise, we might recommend that all people be vaccinated, if and when, we have enough vaccine. But at this time, I think the risk is there. We feel that it is not a high order of risk, but a real risk.
If we should have an attack with smallpox, it would be an extremely serious event. But the risk that it will happen is small. So it is difficult to balance the risks at this time. But right now the recommendation is that we would not vaccinate the entire population, even if we have enough vaccine.
Question from Lou: If you have seen the movie "Outbreak," I wonder what you think a real outbreak of smallpox would compare to that Hollywood depiction of such an event?
Dr. Ken Alibek: It was quite an interesting movie. In my opinion it was a very unusual virus. You would never see this type. It was spread very, very fast, in hours.
Fortunately, it doesn't happen like that. They made a point when they described the infection similar to smallpox. Smallpox would develop slowly but the devastation with smallpox would be similar.
Dr. D.A. Henderson: Our concern is that we try to understand the risk that is there today, with regard to not only smallpox, but also other diseases. We try not to exaggerate. But we try to take reasonable measures to detect quickly, diagnose quickly, and to take appropriate action.
There is a great deal to be done to be reasonably prepared. Our efforts to deal with biological weapons have been very slow to develop. It is a response to make, which is very different than if chemical weapons are released, or an explosion. This is a point, which so many of our planners and politicians simply have not understood.
And yet, the consensus is that the most worrisome of the weapons are the biologic weapons. At this time, we are now beginning to do some of the right things.
Chat Moderator: Do you have any final thoughts to share with us?
Dr. Ken Alibek: When we discuss biologic weapons there is a threat. We can face biological weapons. I want people to realize, unfortunately from my experience, they are effective weapons, not to say that we are facing a real immediate threat from these weapons. It is very difficult to answer because we simply don't know how many countries and organizations are trying to acquire and develop them. But from a technical point, biological weapons are the easiest to manufacture.
If we take this into consideration, we need to realize the 21st century, the century of information technologies, is going to be a century when we will be getting more and more knowledge in biological sciences. Unfortunately, it will be improving our knowledge how to develop biologic weapons.
From this standpoint, we will be seeing a growing threat of the technology to kill people. In my opinion without exaggeration, we need to study our possible responses to this threat, and find new ways to mitigate it.
Dr. D.A. Henderson: I can't add anything to that. It was said very eloquently.
Chat Moderator: Thank you for joining us today!
Dr. Ken Alibek: Thank you for this opportunity. Thank you, Dr. Henderson. You are a great scientist. Thank you, all.
Dr. D.A. Henderson: I second that. I appreciate you putting on this program.
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