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What are biological weapons?

A biological weapon is a weapon that uses disease to kill or harm its target. Here we explain more on what forms they can and have taken in the past.
What are biological weapons? Biological weapons are weapon systems that use disease to cause harm or to kill its intended target. Toxins are also considered to be biological weapons, because they are chemical byproducts of living organisms. The difference between using a toxin and a biological agent is its ability to spread from target to target. While biological agents can be transmitted from one house to another, as a chemical, toxins cannot. Biological weapons can be used to target humans, animals, or plants, and can be used to achieve a variety of aims, such as for targeted assassinations, or to incapacitate a person or persons, spread infection to livestock or crops, to interrupt food production and supply lines, or to cause economic loss.
They can also be used simply to spread fear and create panic, whereby the number of casualties is of less importance than the political, social, or economic effect. There are two components to a biological weapon. It must have a disease causing agent and a means of delivery. There are varying forms of delivery from traditional rockets and missiles down to using insect, animal, or human vectors to spread the disease. The form of delivery mechanism used can depend on the scale of an intended attack, the properties of the disease causing agent, and whether the weapon is for clandestine or obvious use. There are different kinds of organisms that can be used as biological weapons, these include bacteria, viruses, toxins, fungi, and prions.
Examples of bacteriological agents include anthrax, tularemia, and plague, all of which have been pursued as biological weapons agents. Anthrax has commonly been explored by states and others, such as terrorists, as a viable biological weapon, because it is easily produced in a lab, is incredibly hardy and can survive in the environment for long periods of time, can easily be found in nature, can infect humans or animals, and lends itself well to being spread among the population through a variety of means such as powder, sprays, food, and water. Certain viruses are also good candidates to be used as weapons, Ebola virus, Smallpox, and Marburg virus have all been sought to be made into viable bio weapons.
Smallpox is a disease, that has devastated millions over the history of mankind, and has been a staple in states efforts to develop biological weapons. That Smallpox is no longer occurring in the environment, means that governments do not vaccinate the population against the disease. Toxins have been used as weapons in the past, most often as a means for assassination. Toxins such as Ricin and Botulinum toxin a highly lethal, even in minuscule doses, and are easily transported. Ricin occurs naturally in castor beans, making it easy to obtain. While Botulinum toxin is more lethal per gramme, Ricin was the toxin of choice for the assassination of Bulgarian defector Georgi Markov, in London, in 1978.
A Ricin pellet was fired into his leg, from a modified umbrella, by someone associated with the Bulgarian secret police. Certain fungi can be used to cause disease. Fungi cause disease directly by infection or indirectly through mycotoxins and can infect humans, animals, or crops. There are approximately 100 species of fungi, that can cause disease in humans, but many more have a devastating effect on crops and animals. Prion stands for protenacious infectious particle. Prions are responsible for several neurodegenerative diseases found in both animals and humans. These include Kuru and Creutzfeldt-Jakob Disease, CJD, in humans, scraping sheep, and Bovine Spongiform Encephalopathy, BSE, in cows.
Prions are transmissible across animal species, but their long incubation times and possible difficulty in dispersal may not mean they would make effective, wide scale biological weapons.

A biological weapon is any weapon that uses a disease-causing agent to cause harm to its intended target, whether human, animal or plant. A biological weapon can take many forms.

In ancient times, the type and use of biological weapons were primitive and opportunistic such as adversaries poisoning wells with animal corpses or catapulting diseased corpses over walls during sieges. However, with scientific advances and new understandings of how disease works, biological weapons in modern times became more sophisticated and were used in large scale for the first time during World War Two.

Biological weapons have since been banned by the international community in 1972 by the Biological Weapons Convention (BWC), but the threat of the use of biological weapons has since evolved from mainly states to so-called non-state actors (such as terrorist groups).

Today, the threat posed by biological weapons is often characterised as a low-probability, high consequence event but attempts by non-state actors to acquire or develop these weapons has led to international concern and increased efforts to strengthen biosecurity measures to ensure that biological weapons are never used again.

The effects of the use of a biological weapon can vary widely depending upon the agent used, which makes biological weapons very versatile, with the potential to be used in a wide-scale attack, or on a more limited basis for activities such as assassination, or for incapacitation rather than death. The ongoing COVID-19 pandemic could be used to demonstrate the widespread death and disruption caused by even an agent with low lethality, but high transmissibility.

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Next Generation Biosecurity: Responding to 21st Century Biorisks

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