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Molecular Virology and Microbiology

Houston, Texas

BCM has 25 departments and more than 90 research and patient-care centers.
Department of Molecular Virology and Microbiology
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Potential Bioterrorism Agents

Introduction to Bioterrorism Agents

Bioterrorism agents are pathogenic organisms or biological toxins that are used to produce death and disease in humans, animals, or plants for terrorist purposes. These agents are typically microorganisms found in nature, but it is possible that they could be modified to increase their virulence, make them resistant to current antibiotics or vaccines, or to enhance the ability of these agents to be disseminated into the environment.

Terrorists may find biological agents to be an attractive alternative to conventional weapons because of their relatively low costs, their relative accessibility, and the relative ease in which they could be produced, delivered, and avoid detection. Their use, or even threatened use, is potentially capable of producing widespread social disruption.

Salmonella bacteria, a common cause of foodborne disease, invade an immune cell.

Credit: NIAID

The concept of using biological agents in warfare is not new. There are many examples throughout recorded history - even as early as the 6 th century BC when the Assyrians reportedly poisoned wells of their enemies with the fungus rye ergot. In the 1700s during the French-Indian War, it is suspected that the British gave blankets that had been used by smallpox victims to the Native Americans, resulting in decimation of the native population. More recently, in 1984, followers of the Bhagwan Shree Rajneesh contaminated salad bars in Oregon with Salmonella in an attempt to influence a local election (although hundreds were sickened, this attack did not impact the election). However, as our knowledge of infectious disease agents increases, and the technology to design and produce these agents improves, there is an elevated risk that biological agents could used as weapons of mass destruction in the future.

As a result of the terrorist attacks in New York City and Washington, D.C on September 11, 2001 and the dissemination of anthrax through the United States Postal Service shortly thereafter, there has been renewed and urgent attention focused on the possibility of additional terrorist acts involving biological agents. The U.S. government has responded by greatly expanding resources and effort into biodefense research. More than $4 billion has been requested by the president for the 2006 budget for biodefense at the Department of Health and Human Services. Much of this money is targeted to the National Institute of Allergy and Infectious Diseases ( NIAID) component of the National Institutes of Health ( NIH) and the Centers for Disease Control and Prevention ( CDC). These agencies have set research priorities based on a classification system developed by the CDC to categorize the threat of potential agents for use in bioterrorism.

Classification of Bioterrorism Agents

Potential bioterrorism agents are classified into Categories A, B, and C based on
  • their ability to be disseminated
  • their mortality rates
  • their capability of causing public panic
  • actions required for public health preparedness

Category A agents are considered the highest risk agents, and much of the biodefense research effort is directed at these agents. Category C includes agents that are considered emerging infectious disease threats.


Pose the highest risk to national security because they

  • Can be easily disseminated or transmitted from person to person
  • Result in high mortality rates
  • Have potential to cause public panic and social disruption
  • Require special preparedness actions

Pose the second highest risk because they

  • Are moderately easy to disseminate
  • Result in low mortality rates
  • Require enhancement of diagnostic and surveillance capability

Emerging pathogens that could be engineered for mass dissemination because they:

  • Are available
  • Are easily produced and disseminated
  • Have potential for high mortality rates
  • West Nile Virus
  • Caliciviruses
  • Hepatitis A
  • Ricin toxin
  • Salmonella
  • Diarrheagenic E. coli

Biodefense Research

Research efforts in biodefense are directed at
  • understanding the basic biology of potential bioterrorism agents
  • understanding the interaction between the human immune system and these microorganisms
  • developing and improving drugs and vaccines that are effective against bioterrorism agents
  • developing tools to quickly and accurately diagnose diseases caused by these agents
  • establishing resources and biosafety laboratories to facilitate biodefense research.
Colorized transmission electron micrograph showing H1N1 influenza virus particles. Surface proteins on the virus particles are shown in black.

Credit: NIAID

In the Department of Molecular Virology and Microbiology ( MVM) at Baylor College of Medicine ( BCM), research is being conducted on several Category A agents - anthrax, Ebola, smallpox, and tularemia. Work is also ongoing on the Category B and C agents - noroviruses, influenza, and tuberculosis. The research encompasses investigations into the basic biology of these agents, their interactions with the immune system, as well as the development of vaccines and tools to study and combat these agents.

Notably, MVM is home to a Vaccine and Treatment Evaluation Unit (VTEU), one of only seven such sites nationwide. The VTEU is funded by the NIAID component of the NIH and provides the infrastructure to conduct phase I and II clinical trials of candidate vaccines and other biologics for protection against biological weapons and emerging infectious diseases. This unit conducts detailed laboratory investigations of human immune responses to vaccination and epidemiologic and laboratory surveillance for infectious diseases to provide background information for clinical trials. The BCM VTEU is currently evaluating vaccines for anthrax, smallpox, and tularemia. Clinical trials are also underway for vaccines for the prevention of influenza and SARS.

Details of the research being performed in our department on these agents - as well as general information about each of these agents - can be accessed through the link for each specific agent listed on the menu at the left or at the bottom of this page.

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