Medical Countermeasures for Biothreat Agents: in vivo Studies and Animal Models

Abstract

Biothreat agents are prioritized in terms of their threat potentials by taking several factors into account, such as inhalation route of infection / intoxication, infectious dose or toxicity, stability in the environment, and availability of therapeutics / prophylaxis. Most of these factors are intrinsic features of the given pathogen or toxin and are not under our control to modulate. However, pre-exposure prophylaxis and post exposure therapeutics are the criteria that intensive research can handle and dislodge a particular organism from the Select Agent and Toxin List (SATL). Our ability, to impart immunity to human population against an infectious agent and/or treat the disease, substantially mitigates a potential threat and renders the agent obnoxious from bioterrorism or warfare viewpoint. For instance, Clostridium tetani and its neurotoxin are equivalent to Clostridium botulinum at least in terms of the lethality of the neurotoxins but the former is not considered a potential select agent for the availability of prophylactic measures and immunization regimen. The problems associated with pre-exposure prophylaxis for threat agents is confounded by several factors including the long list of select agents and the uncertainty of use for a particular agent. For the agents of public health importance, we are aware of the endemecity of natural disease outbreaks, but it is difficult to predict which agent will be used in a bioterror or BW attack. Theoretically, a pre-exposure prophylaxis in biothreat scenario requires immunization against all the agents or least against those posing potential threat. Assuming that we have developed vaccines for each of the threat agents, the vaccination of even a vulnerable population for this wide array of pathogens is a magnanimous task.