cultural risks which were mentioned briefly but not discussed in detail during this workshop.
B. anthracis is a very stable organism because of its ability to sporulate. Most naturally occurring anthrax cases are cutaneous and are transmitted from agricultural exposure. The incidence of infection is unknown; most cases occur in underdeveloped countries. Throughout the world, since the late 1930s, attenuated strains have been used as live veterinary spore vaccines and have proven to be highly effective in controlling disease in domesticated animals. Since the 1950s, one of these strains has been used as a live attenuated strain in humans in countries of the former Soviet Union. The molecular pathogenesis of anthrax, including the exact target of its lethal factor, is largely unknown. However, enough is known that we can begin to predict where second-generation vaccines and various antitoxin modalities might work.
Currently, there are three types of preventative or therapeutic countermeasures against anthrax: vaccination, antibiotics, and various adjunctive anti-toxin treatments. In terms of developing new therapeutics, initial immediate efforts should be to evaluate already licensed antibiotics. Longer-term efforts should include identifying protective antigens that are effective against modified strains; developing vaccines that act more quickly and would be more useful in a post-exposure scenario; exploring the combined use of vaccines and antibiotics; and exploring new antitoxin treatments. Critical to all of these efforts is the need for a large-scale central animal testing facility.
Smallpox has several features that make it an attractive bioterrorist agent: it is highly stable; it is infectious by aerosol; it is highly contagious; most clinicians lack experience recognizing the disease; and, because vaccination against smallpox ceased after eradication, most of the world’s population is highly susceptible to infection.
Even though a smallpox vaccine exists, there are several unresolved bioterrorism-related issues regarding smallpox vaccination:
It is not clear which health care providers should be immunized preceding any potential outbreak versus immediately following an outbreak.
The current supply of vaccinia immune globulin is insufficient for treating all of the expected adverse effects associated with vaccinia immunization, should all 300 million doses of cell-cultured vaccinia that are currently being produced be administered.