Category A agents are biological pathogens that could pose a threat to health and human safety if used as bioweapons. The exploration and possibility of these threats must be comprehensively reviewed to create a preparedness plan to recognize outbreaks, to educate the public, and to offer vaccinations and/or treatment options, if available. A scoping review using PRISMA guidelines was performed to categorize current information on Category A biological agents as well as understand their potential for future threats. The results used 34 articles and found that while botulin neurotoxins were the most lethal, anthrax posed the most likely threat for use as a bioweapon. Most research was conducted on plague, though it is not the most likely threat. Smallpox is the most likely agent to vaccinate against as there is already a working vaccine that has proven effective and the issue at hand is the need for a larger stockpile. Ultimately, preparedness efforts should include vaccinations and continued research and development of them. Category A agents are a serious public health concern; updated and reformed bioterrorism preparedness plans could greatly minimize panic and mortality.

Botulism is a neuroparalytic disease caused by neurotoxins produced by the bacteria Clostridium botulinum. Botulinum neurotoxins (BoNTs) are among the most potent naturally occurring toxins and are a category A biological threat agent. The 7 toxin serotypes of BoNTs (serotypes A–G) have different toxicities, act through 3 different intracellular protein targets, and exhibit different durations of effect. Botulism may follow ingestion of food contaminated with BoNT, from toxin production of C botulinum present in the intestine or wounds, or from inhalation of aerosolized toxin. Intoxication classically presents as an acute, symmetrical, descending flaccid paralysis. Early diagnosis is important because antitoxin therapy is most effective when administered early. Confirmatory testing of botulism with BoNT assays or C botulinum cultures is time-consuming, and may be insensitive in the diagnosis of inhalational botulism and in as many as 32% of food-borne botulism cases. Therefore, the decision to initiate botulinum antitoxin therapy is primarily based on symptoms and physical examination findings that are consistent with botulism, with support of epidemiological history and electrophysiological testing. Modern clinical practice and antitoxin treatment has reduced botulism mortality rates from ∼60% to ≤10%. The pentavalent botulinum toxoid is an investigational product and has been used for more than 45 years in at-risk laboratory workers to protect against toxin serotypes A to E. Due to declining immunogenicity and potency of the pentavalent botulinum toxoid, novel vaccine candidates are being developed. (Disaster Med Public Health Preparedness. 2007;1:122–134)