Biological weapon

Characteristics and agents

Biological agents include living organisms and their products. Common categories are toxins or pathogens, such as bacteria and viruses. Some agents cause rapid, acute illness while others produce slower, persistent effects. Delivery can be by aerosol, contamination of food or water, or direct contact, and effectiveness depends on factors like dose, environmental stability, and incubation period.

History and legal controls

Use of disease in conflict has a long history, and modern concern led to international agreements to prohibit such weapons. The 20th century saw state programs and documented abuses that spurred treaties and norms restricting research and deployment. Today, multilateral instruments and national laws regulate biosafety, biosecurity and oversight of potentially dangerous work.

Uses, impacts and examples

Biological weapons have been used or developed in several historical episodes, producing humanitarian and public health crises. Civilian populations are particularly vulnerable because pathogens can spread beyond intended targets. The same properties that make some agents medically important also make their misuse hazardous: small-scale incidents can require large responses in public health, medical care and law enforcement.

Distinctions and prevention

Biological weapons differ from chemical or nuclear arms by relying on living systems and transmissibility. Preventing misuse combines scientific safeguards, intelligence, surveillance, emergency preparedness and international cooperation. Policy debates balance legitimate biomedical research against risks of dual use. For discussion of the concept in armed conflict see biological warfare.

• Key control topics: detection, medical countermeasures and legal prohibition.
• Relevant agent categories: toxins/pathogens, bacteria, viruses.
• Further reading and definitions: definition, policy resources bacterial threats, viral threats.