Biodefense: Eliminating the Threat

In the biowarfare field, effective preparedness is the key to mounting a successful response, and preparedness begins with a strategic assessment of the threats and risks involved and a clear focus on the means available to counter those threats. Today, there are numerous agents – anthrax, smallpox, plague, and a broad spectrum of other organisms – that can be used as weapons of terror, either by state or non-state actors. That same list includes infectious agents that not only are highly lethal but also may be spread in a variety of ways that can affect a large number of people within a very short time frame. There are also toxins, such as botulinum toxin, associated with infectious agents that pose major threats.

By accepting the facts that these threats are real and that delivery of these agents is not only feasible but also a deliberate goal of those who want to do harm to the United States, appropriate planning and training processes can be developed to robustly address the threats. Marshaling the human and material assets needed, and training and exercising them for probable use if and when an attack does occur, are essential aspects of an effective preparedness posture, which also should include the development and acquisition of the specialized medical countermeasures and equipment systems needed to protect the population. Fortunately, significant progress already has been made in the development of: (a) the newer vaccines required to prevent illness; (b) the improved treatment modalities – monoclonal and polyclonal antibodies, for example – that can protect against toxins as well as organisms; and (c) new generations of antibiotics that will be more effective than their predecessors. Many of these resources are now in the Strategic National Stockpile, but more sustainable means of assuring their quick and continuing availability must still be developed and implemented.

The current U.S. planning process is, however, predicated on the ability to know when and where to deploy these capabilities and material resources. To begin with, there must be anentified “trigger” – that is, a clear signal that a specific known infectious agent is already in the environment and has been released – before action can be initiated. For that reason alone, early biodetection is a critical aspect of the preparedness planning and implementation process and can be achieved by a variety of means (some of them more timely than others).

Biodetection to Initiate Action Ideally, early detection will lead to a swift intervention that provides the maximum protection for the affected population. This is particularly true in situations involving anthrax, because it is well known that the provision of antibiotics and vaccine within the first 48 hours after exposure to anthrax spores reduces both the number of cases that develop and the number of probable deaths. Again, in aneal world, detection within a very short time frame – ranging from several minutes to only a few hours after release of the spores – would be of significant benefit.

New technologies already exist that permit the remote sampling of environmental air needed not only toentify the presence of threatening organisms but also to transmit that information within three hours of the sample collection. This is a major improvement over the current 24-36 hour limit required for environmental detection. The new technology, however, has not yet been deployed because: (a) there are legitimate questions to be answered about false positives and negatives; and (b) certain other (non-technical) issues also must be resolved.

Among the other means used to detect the presence of a threat are clinical syndrome surveillance and the analysis of clinical laboratory information. The term “clinical syndrome surveillance” relates to the monitoring of certain clinical signs and symptoms, reported from emergency rooms and other medical care facilities and typically associated with theentified threat. The “signs and symptoms” refer to a relatively late set of events indicating that a particular threat agent has been in the environment long enough to cause clinical illness.

In practice, though, any responses generated in these circumstances usually would not be as effective as desired in preventing future illnesses and deaths, primarily because activation of the response system would by definition be much later than the emergence and dissemination of the disease-causing agent. Nonetheless, with many diseases and in many communities, this information might well be the first indicator that an infectious-agent event has begun. Various clinical laboratory tools may provide specificentification of the agent or agents involved – and these tools, even when used late in the exposure process, would still be useful in confirming and measuring both the time of exposure and the specific agent(s)entified.

Response, Recovery & Protecting the Protectors After an infectious agent has beenentified in the environment, an effective response should be directed and the assets needed quickly deployed. The effectiveness of any given response may vary considerably, depending upon the agent itself. In some cases (usually associated with bacterial diseases), antibiotics should be the first line of response. In other cases (usually viral illnesses), the use of vaccinations is the most useful approach. In all cases, though, medical surge assets are urgently needed and require the deployment and distribution of people, medicines, medical supplies, and other tools and equipment – ventilators, for example.

The effectiveness of medical surge responses is highly dependent upon the effectiveness of the planning and exercising phases of the long-term preparedness plan. The anticipation of probable needs, combined with theentification and training of the systems of care likely to be involved, are the usual determining variables that lead to saving lives and reducing the overall burden of illness. To some degree, the protection of healthcare workers themselves, and their families, is also a critical factor that must be taken into consideration to ensure that the response personnel needed are both healthy and quickly available. Specifically how the protection of healthcare workers is or should be provided is another major issue that has not yet been resolved.

Lastly, recovery to a new, higher, and more complex definition of “normal” offers significant challenges – for example, how the potential lingering effects of certain agents are or should be mitigated or remediated. Perhaps the most significant example, particularly in anthrax cases, involves the removal of remaining spores – a huge challenge, obviously, when a major metropolitan area such as New York City has been the target of a terrorist attack. The removal techniques may be simple in some cases, but in other cases not only very expensive but also very time-consuming.

Deterrence: Critical Questions & Assumptions Another critical question that must be considered is whether the level of spores remaining in the local environment has returned to an acceptable level – one that is safe for the return of the local population. Working on the assumption that 100 percent removal may be required, in most if not all situations, that complex question still requires a major policy answer at all levels of government. Whatever the answer, though, the adverse impact on the economy, and to the American people at large, may be so great that any pre-event assumptions would be of little or no practical use.

If all of the above elements are demonstrated to be in place and effective response and recovery operations might reasonably be expected – and, in fact, demonstrated through drills and exercises – then the goals of saving lives, reducing the burden of illness, and recovering to a new standard of normal can be achieved. In addition, and of perhaps greater importance, the threat itself may be deterred. In other words, the demonstration by any community, large or small, of a much improved ability to respond and recover from an infectious-agent attack might in itself reduce the possibility of an attack such as that described here.

The heightened preparedness and response posture and capabilities of communities throughout the nation therefore would serve as a deterrent, and that would be another important reason for undertaking the considerable and difficult efforts involved. By lessening the probable impact of biothreat attacks, the nation thereby would also lessen the attractiveness to would-be terrorists of using biowarfare weapons. The ultimate goal of the national strategy for biodefense, therefore, should be not merely to respond to and counter the threat, but to eliminate it completely.

W. Craig Vanderwagen

Rear Admiral W. Craig Vanderwagen, M.D., was appointed the Department of Health and Human Services (HHS) Assistant Secretary for Public Health Emergency Preparedness and promoted to the rank of Rear Admiral, Upper Half, U.S. Public Health Service (USPHS) in July 2006. He now serves as the Deputy Assistant Secretary for Preparedness and Response and Chief Preparedness Officer. In this position, he is the HHS Secretary's principal advisor on matters related to bioterrorism and other public health emergencies. The mission of his office is to lead the nation in preventing, responding to, and reducing the adverse health effects of public health emergencies and disasters. Admiral Vanderwagen has significant public health emergency and disaster-response experience. Most recently, he was the deputy secretary's special assistant for preparedness and led the teams that implemented the changes at HHS recommended in the White House Report Katrina Lessons Learned. He also: was the senior federal health official in the response to Hurricanes Katrina and Rita in Louisiana; led the public health team deployed on the hospital ship USNS Mercy to Indonesia to assist in the 2005 tsunami recovery; served as chief of public health for the Coalition Provisional Authority and Ministry of Health in Iraq; and directed some of the health care operations initiated to help Kosovar refugees during the 1999 Balkans conflict.



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