A biological weapon is a weapon that delivers toxins or pathogens (like bacteria or viruses), with the goal of making people sick or killing them.[1][2] Biological weapons are also called bio-weapons. Their use in war is called biological warfare.
A biological weapon usually has two parts.[2] The first is the biological agent (also called a bio-agent, biological threat agent, or biological warfare agent). This is the pathogen that is meant to make people sick. The second is the delivery system - how the biological agent is going to get to and expose the people it is supposed to infect.
Some bio-agents can be "weaponized" - changed to make them more dangerous. For example, sometimes scientists can change a pathogen's genes so the pathogen is deadlier, and so it will not be killed by usual antidotes or treatments. Some bio-agents can be changed so they are easier to store, spread, or use as weapons.[3]
As of 2016, there are more than 1,200 different kinds of bio-agents that could be made into weapons.[4]
Examples of some biological agents and toxins are listed below. Experts have said that these pathogens could be used as biological weapons.[2][5][6][7] A few already have been used, including anthrax, bubonic plague, smallpox, and ricin.
Pathogen | Disease | Comments |
---|---|---|
Bacillus anthraces | Anthrax | Was weaponized by the U.S., Soviet Union, and Iraq[6]p. 26 |
Brucella species | Brucellosis | Brucella suis was the first bio-agent weaponized by the U.S., in 1954; Brucella species easily survive in aerosol form[6] |
Yersinia pestis | Bubonic or pneumonic plague | Killed 60% of Europe's population in the 1300s.[8] Pneumonic plague is fatal if antibiotics are not given within 1 day after symptoms start[6]p. 55 Weaponized by U.S. and Soviet Union during the Cold War[8] |
Vibrio cholerae | Cholera | Could be spread by contaminating water supplies[9] |
Shigella dysenteriae; Some species of Escherichia coli |
Dysentery | Could be spread by contaminating food supplies[10]p. 212 |
Coxiella burnetii | Q fever | Number of bacteria needed to infect a person is one - the lowest known to man[6]p. 67 Can live on surfaces for 60 days, in aerosols, and in many temperatures[11] Weaponized by U.S. between 1942 and 1969[6] |
Francisella tularensis | Tularemia | Very contagious; bacteria are very easy to get because they occur in nature; Weaponized by U.S. between 1942 and 1969[6] |
Rickettsia prowazekii | Typhus | High mortality rate if untreated; can be spread by aerosol[10]p. 169 |
Staphylococcus aureus | Many | Could be spread by contaminating food supplies or by aerosol[12] Some strains (like MRSA) are resistant to antibiotics[13] |
Pathogen | Disease | Comments |
---|---|---|
Alphaviruses | Many | Can cause many forms of viral encephalitis; very low dose needed for infection. Easily spread by aerosol.[6]p. 96 |
Filoviridae and Arenaviridae viruses | Many | Cause viral hemorrhagic fevers, like Ebola virus and Lassa fever Can be spread by aerosol; very high mortality rates[6]p. 107 |
Variola major | Smallpox | Very contagious, easily spread through air, mortality rate 20-40% Eradicated in 1970s, but laboratories still have samples[14] |
Toxin | Toxin Comes From: | Toxin Causes: | Comments |
---|---|---|---|
Botulinum | Clostridium botulinum | Botulism | One of the deadliest toxins known to exist; Weaponized by U.S. between 1942 and 1969[6]p. 122 |
Ricin | Castor oil plant | Ricin poisoning | Can be made at home; very toxic by any route of exposure[15] |
In the past, countries have designed many different delivery systems for exposing people to biological agents. These systems have included:[2]
A biological agent by itself is not enough to make a biological weapon. Neither is a delivery system by itself. A biological weapon has to have both: the bio-agent that is meant to make people sick, and a system to deliver that agent.[2]
Here are a few examples of biological weapons that have been used throughout history.
Year | Bio-Agent | Delivery System | Used By |
---|---|---|---|
1346 | Yersinia pests (plague) | Corpses of bubonic plague victims | Tartar army to attack Crimea[1] |
1763 | Variola major (smallpox) | Blankets from smallpox victims | British soldiers to attack Native Americans[1] |
1940s | Yersinia pests (plague) | Plague-infected ticks dropped from airplanes | Japan to attack China during World War II[6]p. 56 |
1941 | Vibrio cholerae (cholera) | Contaminated food & water | Japan to attack China[9] |
2001 | Bacillus anthraces (anthrax) | Mailed letters | Terrorists to attack U.S. politicians and news stations[16] |
2013 | Ricin | Mailed letters | Terrorists to attack U.S. President Obama and a U.S. Senator[15] |