Security Studies Program Seminar

Biological Agents:
Threat, Preparedness, Response, and Myths

James J. Valdes
Scientific Advisor for Biotechnology
US Army Research, Development, and Engineering Command

December 7, 2005


Since the anthrax incident four years ago, there has been a great deal of hype about the threat of bioterrorism. Unfortunately for those seeking a balanced set of counter-bioterrorism policies, there are significant bureaucratic interests within the government, in the private sector and in the media in encouraging that hype. The result has been a great deal of popular mythology surrounding the threat of a bioterror incident.

Counter-bioterrorism efforts are usually divided into two categories. Biodefense focuses on Category-A diseases and toxins deployed by states and transnational actors. The US Department of Defense is primarily focused on these types of efforts. Biosecurity includes, but is not limited to, biodefense and deals with all forms of biological public health concerns, including bioterrorism, natural epidemics, etc.

One popular misconception is the conflation of biological agents and chemical agents. The critical differences between these two types of agents are listed below:


Biological Agents

Chemical Agents

- Naturally occurring

- Man-made

- Production is difficult

- Production is difficult

- None are volatile

- Many are volatile

- More toxic than man-made toxins

- Less toxic than naturally-occurring toxins

- Self-replicating

- Do not replicate

- Most are not dermally active

- Many are dermally active

- Legitimate medical use

- No use other than as weapons

- Odorless and tasteless

- Odors or colors

- Diverse pathogenic effects

- Fewer types of effects

- Many are effective immunogens

- Poor immunogens

- Aerosol delivery is difficult

- Mist / droplet / aerosol delivery

- Delayed onset

- Rapid onset

- A few are contagious

- Not contagious


The likelihood of a bioterrorist attack is inversely related to the likely number of casualties. This is because the most devastating types of attacks are very difficult to carry out, and therefore unlikely, whereas a more limited attack resulting in few casualties would be easier to carry out. Furthermore, the intentions of potential attackers are critical to biodefense assessments. A mass casualty attack using aerosolized agents delivered by aircraft or ICBMs would require state sponsorship. An attack intended to cause only economic damage, one that targets livestock or food supplies, is unlikely given the attentive inspection infrastructure that already exists in these industries. The real threat is an attack intended to cause societal disruption, rather than mass casualties. These attacks consist of limited releases of agents within a local area.

Thus, biosecurity is a complex problem, given the diverse characteristics of the targets. The threat footprint may be quite small and may initially appear to be a natural disease, making attribution of an attack virtually impossible. Unfortunately, materiel solutions are not sufficient; biosecurity is fundamentally a public health problem.

A particular set of diseases is usually mentioned in the context of biological warfare. The human diseases most often considered are smallpox, cholera, shigellosis, and others. The category of dangerous zoonoses, i.e. diseases carried by animals but that may infect humans, includes Ebola, Marburg , plague, rabies, and tularemia. Animal diseases include Foot and Mouth and Mad Cow disease. For many of these Category-A diseases, prophylactics or treatments are available. However, the question of resource allocation persists: should vaccines, treatments, or alternative options be purchased? The trend in research has shifted from a preference for vaccines to more generic approaches. The question of resource allocation is a critical one, given the amount of money devoted to biosecurity. In fiscal year 2006, the federal government devoted $100 million to a new drug development program.. This amount is currently scheduled to rise to over $1 billion in fiscal year 2007.

The problem of biosecurity is further complicated by several additional factors. First, many diseases begin with flu-like signs and symptoms, making the initial diagnosis difficult. Definitive preclinical diagnostics are specific and complex to perform, while post-clinical diagnosis treatments may be too late. Few antiviral drugs are available to combat these agents, and widespread preventive vaccinations may not be a viable option. Furthermore, all of the current methods for identifying biological agents, which include culture and isolation, animal inoculation, immunoassays, nucleic acid assays, and mass spectroscopy, are too slow to provide instant assessments. The challenges facing environmental detection and timely diagnosis are as follows:

•  Logistics (power and reagents)
•  Sensitivity
•  Background interference
•  Timeliness
•  Detect to warn versus detect to treat?
•  Detection sensitivity must be very efficient
•  Sample collection
•  Sample presentation
•  Complex matrices
•  Accurate differentiation
•  Miniaturization

Despite the complexities involved in biosecurity and the hype surrounding the issue, bioterrorism has a fairly unimpressive history with very few casualties. This is primarily due to the extensive constraints on the bioterrorist weaponeer. Having a respirable aerosol is vital to an effective attack, yet the weaponization process often jeopardizes the viability of the agents. Furthermore, aerosols are vulnerable to inclement weather conditions.

Given the unimpressive history of bioterrorism and the ongoing challenges facing aspiring bioterrorists, what is the real threat? Here are some facts to consider: In the US alone, 90,000 people die each year from hospital infections, 36,000 people die from the flu, 15,000 people die of AIDS-related illnesses, and 5,000 people die from Hepatitis B. Mother Nature presents at least one major infectious disease per year. Therefore, are current vaccine and detection policies good policies? We are currently engaged in an arms race against bacteria, one in which we spend $30 billion per year is the additional cost of combating the most antibiotic-resistant bacteria.

How can we enhance biosecurity? First, we should work to reorganize live bird markets worldwide, since birds carry the most dangerous strains of flu virus. Second, we need to ensure a much more rational use of antibiotics. Third, we should encourage an education campaign to reduce the phenomenon of the "worried well" overwhelming emergency services in the event of a bioterror incident. Finally, we should consider using the public workforces as "bio-sentinels." Through the use of non-invasive thermal imaging on urban workforces, we can reliably monitor disease patterns as they emerge..

What has changed since 9/11 in the area of bioterrorism and biosecurity? There is obviously a clear intent to harm by potential attackers. There are new diseases to be fought. There is heightened public awareness about bioterrorism, though the public may be generally under-informed about the nature of this threat. There has been a dramatic increase in funding for bioterror preparedness. And finally, widespread immunization against certain pathogens has been considered as a policy option. That said, certain aspects of the bioterror and biosecurity issue have not changed. First, biological agents remain difficult to prepare and weaponize. Second, it remains difficult for law enforcement and intelligence agencies to gather intelligence about potential bioterror threats. Finally, the value of good public health for preparedness has remained high.

What are the broad lessons to be drawn from this presentation?

•  Think public health
•  Think dual-use investments
•  Think technology-based not materiel-based
•  Think education
•  Think cost-benefit
•  Think long-term


Summarized by: Adam Brody

back to seminar summary, Fall 2005