Defense Against Toxic Weapons: Intelligence that Protects the Soldier

by David R. Franz

Defense Against Toxic Weapons

The Future

INTELLIGENCE: Information that protects soldiers

Readers of this document should now understand several important points about protecting soldiers and targets of terrorist attack from toxin weapons:

1) Fifteen to twenty of some 400 known toxins have the physical characteristics that make them threats against U.S. forces as potential MCBWs. However, many toxins could be used in weapons to produce militarily significant/terrorist (psychological) effects-especially in poorly educated troops or in uninformed civilian populations.

2) Effective individual physical protective gear is available; soldiers must receive timely warning of an attack, however, if they are to use their protective masks effectively.

3) Most of the toxins with the characteristics that make them threats as MCBW are proteins, which is to our advantage; vaccines or passive antibody therapy are developed relatively easily.

4) Immunizing troops, much preferred to treating intoxicated troops after exposure, typically requires a minimum of 4-15 weeks.

5) Development of medical countermeasures against likely MCBWs is feasible.

In addition, research for and development of a vaccine or passive antibody therapy through final approval by the U.S. Food and Drug Administration as a product for human use is likely to require a minimum of 4-7 years (8-10 years in some cases). Because developing and producing countermeasures takes years, intelligence information regarding toxin research for weapons development and aggressor capability analysis is invaluable. Our own understanding of the physical characteristics of toxins, even without intelligence information, allows us to deduce what may be possible for the aggressor; this information reduces the list of toxins from hundreds to less than 20. Good intelligence on threat research and development can, at a minimum, help those responsible for research and development of medical countermeasures prioritize finite resources, and thus reduce the time of the research and development cycle. Good intelligence on weaponized toxins held by an aggressor will also greatly assist leaders who must makedecisions to immunize troops as they ppare for conflict. Therefore, as regards medical defense against toxin weapons, a strong and effective intelligence effort is both necessary and cost-effective.

TOXINS AS WEAPONS

Research literature suggests that we have discovered the majority of the "most toxic" (LD50 < 0.0025 micrograms/kilogram) naturally occurring toxins. New toxins of lesser toxicity, especially the venom toxins, are being discovered at the rate of perhaps 10-30 per year. There is little precedence in the literature for artificially increasing the toxicities of naturally occurring toxins; however, it might be possible to increase the physical stability of toxins that are toxic enough but too unstable to weaponize. This could increase the effectiveness of the threat toxins.

It is unlikely that chemical synthesis of complex nonprotein toxins will become significantly easier in the near future. It is likely, however, that large-scale biosynthesis of peptide toxins of 10-15 amino acids (some of the venom toxins) will become possible in the next few years.

I have attempted to present a rationale for focusing our medical biological defense resources on the development of medical countermeasures for those toxins that our soldiers are most likely to face on the battlefield in the next 5 years. We must also continue limited basic research efforts and maintain "technical watch" of the peptide and other toxins that could become the next generation of toxin weapons. Medical defense against biological weapons requires constant vigilance, especially today, because biotechnology is now available worldwide.

COUNTERMEASURES TO TOXINS

Although the threat of toxin weapons of the future is formidable, the prospect of new and better medical countermeasures is brighter than ever before. Biotechnology may have more value to those of us developing countermeasures than to those who would use toxins maliciously. Molecular biological techniques developed in the last few years now allow us to produce more effective and less expensive vaccines against the protein and peptide toxins. Such vaccines will likely be available for the most important toxins within the next few years. We are making good progress on developing recombinant vaccines for certain highthreat toxins. Similar technology allows us to produce human antibodies, which will eventually replace those now produced in animals. Human antibodies will be a significant advance over despeciated horse antibodies, allowing us to protect unvaccinated soldiers by simply giving them an injection before they go into battle, thereby providing immediate protection. Human antibodies could also find application in counterterrorism as therapy.

PROTECTING SOLDIERS

Protecting soldiers on the battlefield from toxins-and replicating agents-is possible if we use our combined resources effectively. Physical countermeasures such as the protective mask, clothing and decontamination capabilities exist and are effective; as we improve our battlefield detection systems, early warning of our soldiers may become a reality, at least in subpopulations within our forces. These assets, unlike most medical countermeasures, are generally generic and protect against most or all of the agents. Among the medical countermeasures, vaccines are available and effective for some of the most important agents and therapies exist for others. Because of limited resources available to develop vaccines, diagnostics and therapies, we can field specific medical countermeasures only to a relatively small group of threat agents. Our efforts in this area must be carefully focused. A third and complementary element of our defensive program must be good intelligence. Only through knowledge of specific threat agents, delivery systems, and national capabilities can we assure effective development and use of our physical and medical countermeasures.

Finally, our renewed understanding of the real strengths and weaknesses of toxins as weapons allows us to put them in perspective in educating our soldiers, removing much of the mystique-and associated fear-surrounding toxins. Knowledge of the threat thus reduces the threat to our soldiers.