A
biological agent—also called
bio-agent,
biological threat agent,
biological warfare agent,
biological weapon, or
bioweapon—is a
bacterium,
virus,
protozoan,
parasite, or
fungus that can be used purposefully as a weapon in
bioterrorism or
biological warfare (BW). In addition to these living and/or replicating
pathogens,
biological toxins are also included among the bio-agents. More than 1,200 different kinds of potentially weaponizable bio-agents have been described and studied to date.