Bioterrorism: How Great Are the Risks?
Dr. Elizabeth M. Whelan
Remarks Delivered at Debate with Richard Preston, Author of The Demon in the Freezer.
Sponsored by the Donald and Paula Smith Family Foundation
Thursday, November l4, 2002, at the City University of New York
Good evening. The question at hand here tonight: bioterrorism, how great are the risks? The answer: we do not know how great the risk is, but we do know the risk is not a hypothetical one. The risk is real.
We know or strongly or strongly suspect that countries that despise America and our enviable way of life have biological weapons. The horrific events of September 11 and the subsequent dissemination of anthrax through the U.S. mail are clear evidence that terrorists domestic or international are willing and able to use advanced technologies to kill us on a large scale.
We must be prepared for the possibility that bin Laden, Iraq, North Korea, or whomever will try to kill Americans with biological agents. The top six biological threats are: anthrax, smallpox, plague, tularemia, botulism toxin, and the agents of viral hemorrhagic fever. Given time limitations, I will focus here only on the first two.
Anthrax: A Real Threat and a Safe, Effective Vaccine
Anthrax is very high on my list of bioterrorism concerns. Again, this is not a hypothetical. We know Saddam has anthrax. When "properly" dispersed, anthrax is a highly effective way to kill hundreds of thousands of people.
It concerns me greatly that Americans seem to be relatively complacent about the possibility of another anthrax attack. About thirteen months ago, anthrax was used as the murder weapon in the killing of five Americans, leaving seventeen more ill. The anthrax attacks back then commanded our national attention and were enormously disruptive and costly, but when it was over, I am afraid, it left Americans with the mistaken belief that (a) because it is a bacteria and is not communicable, it's not worthy of substantial attention, and (b) "in Cipro we trust" was the solution just pop some readily-available antibiotics and you'll be fine.
Such complacency is not grounded in fact. Again, if "properly" dispersed, anthrax spores can enter the lungs without the host's knowledge. The anthrax attack of 2001 used just one of the delivery systems which are available. The use of aerosol delivery technologies inside buildings or over large outdoor areas is another method of attack, one which has been studied. An anthrax accident in the former Soviet Union that involved aerosol release resulted in an epidemic of anthrax disease. An aerosol release would be odorless and invisible and would have the potential to travel miles before dissipating. Once in the moist environment of the lungs, the bacteria would thrive, and it is very possible that we might never know an anthrax exposure has occurred and possibly has involved large numbers of people until a cluster of individuals in severe respiratory distress show up in the emergency room. At that point, Cipro or any antibiotic will be of very little use.
Given the known risk of anthrax, it seems to me that we should be giving serious consideration to increasing the supply of the anthrax vaccine which, by the way, is known to be safe and effective. What is the current supply of such vaccine? I don't think anyone, other than those privy to information relative to national security, knows.
Smallpox: Still Only a Hypothetical Risk
When we turn from anthrax to the threat of smallpox (smallpox being the primary topic of Richard Preston's frightening book), we go from the real to the hypothetical. As far as we know, there are only two current sources of the smallpox virus: in freezers in Atlanta and Russia. Yes, we have all heard reports that Iraq, North Korea, Russia, and France have viral samples and have experimented with them as a bioweapon. But we do not know this for sure.
How do we go about making informed decisions about preparing ourselves in this case initiating a vaccination program for a hypothetical risk? Unlike the anthrax vaccine or routine childhood and flu shots, the smallpox vaccine carries known risks even for healthy people, with an estimated death rate of one or two per million and a significantly higher rate of other side-effects from adverse reactions, including brain swelling. The challenging question is this: how do we weigh a hypothetical risk of being exposed to smallpox with a small but real risk of vaccine-related death or illness?
I am aware that there is a growing public fear of even the hypothetical risk of smallpox, and a substantial number of Americans now argue that they should be able to make their own decisions on how to protect their health, thus they should have access to the vaccine. I sympathize with this argument, but the issues here are very complex, particularly regarding the unknown extent of serious effects that might occur among the newly vaccinated persons and those with whom they come in contact.
I think we have a way of resolving the struggle between those who advocate smallpox vaccine availability for all who want it and those who wish to protect people from untoward effects until we know for sure that smallpox is available as a weapon to terrorists.
The key here is getting hard data on what exactly the side effects are so that Americans can indeed make informed decisions that weigh benefit and risk. And how do we get that data? We should look to Israel, which apparently has recently vaccinated large numbers of first responders. Also, as we begin vaccinating key medical personnel here (the ones who would be most likely to see the first cases of smallpox), we will be creating a database for determining exactly what the side effects are so we may extrapolate to determine the actual risks should the entire population be vaccinated. At the same time, we should be increasing our supplies of vaccinia immune globulin (VIG), which can effectively treat severe reactions.
For many, a more palatable alternative to mass vaccination would be assured access to the vaccine when and if it were confirmed that smallpox was again on the scene.
Flaws in Preston's Book
In considering the unspeakable possibility of smallpox being re-introduced, we need to approach preparedness in a scientific, rational, non-hysterical manner. I differ with my opponent tonight in that I believe our public health system could manage and contain a smallpox epidemic. Specifically, I take exception to at least three allegations made in Mr. Preston's book.
Point 1: the degree to which smallpox is contagious. He maintains that smallpox can spread from person to person even without direct contact, citing examples where people allegedly became infected by individuals they had never actually seen or been in close contact with. Actually, according to JAMA experts, smallpox spreads from person to person primarily by droplet nuclei or aerosols expelled from the infected person by direct contact. Historically, the rapidity of smallpox transmission throughout the population was generally slower than for such diseases as measles or chicken pox. Patients spread smallpox primarily to household members and friends. Large outbreaks in schools, for example, are uncommon.
Point 2: Mr. Preston writes " people who are coming down with smallpox have days of early illness when the virus is leaking into the air from their mouths but they have not begun to develop a rash." If he is implying that people are infectious in this early stage before they themselves are clearly ill, he is incorrect. Quoting JAMA again, "the transmission of smallpox virus does not occur until onset of rash. By then, many patients have been confined to bed because of the high fever and malaise...Secondary cases are thus usually restricted to those who come in contact with patients, usually in the household or hospital...Patients are most infectious from the onset of the rash through the first seven to ten days of the rash."
Point 3: Mr. Preston states that those of us who were vaccinated years ago have lost all or most immunity to smallpox. Researchers writing recently in the NEJM suggested that the vaccination may offer protection for thirty-five years, maybe longer (although not all smallpox experts agree with this conclusion, saying residual immunity might depend on how often we were vaccinated years ago and the method of inoculation used).
In summary, the threat of a bioterrorist attack on the U.S. is real, but we must approach that threat rationally and scientifically. We need to inform people but not overly alarm them. Unfortunately, Richard Preston's extremely well written book may have an unnecessarily frightening effect. Or as a New York Times book review of Demon in the Freezer last month noted: the reality of bioterrorism is frightening enough without Mr. Preston's theatrical stage craft.
