"Diseases can be caused naturally by s such as bacteria, viruses and s (natural risk). However, such biological agents can be intentionally disseminated in the by a State (military context) or terrorists to cause diseases in a population or , to destabilize a nation by creating a climate of terror, destabilizing the economy and undermining institutions. Biological agents can be classified according to the severity of illness they cause, its mortality and how easily the agent can be spread. The (CDC) classify biological agents in three categories (A, B and C); Category A consists of the six pathogens most suitable for use as bioweapons (', ', ', , smallpox and s). represent a perfect biomedical countermeasure as they present both prophylactic and therapeutic properties, act fast and are highly specific to the target. This review focuses on the main biological agents that could be used as s, the history of biowarfare and antibodies that have been developed to neutralize these agents."