What are Biological Weapons?
This short introductory video lecture covers the following topics:
- biological agents
- enhanced pathogens
- synthetic agents
- delivery systems
- detection of biological weapons and biowarfare programmes
Biological weapons are complex systems that disseminate disease-causing organisms or toxins to harm or kill humans, animals or plants. They can take many different forms, but generally consist of two parts: a weaponized biological agent and a delivery mechanism.
While almost any pathogenic organism or toxin can be used as a biological weapon, to be useful to the military, biowarfare agents have traditionally been seen to require certain characteristics: They should be dispersible as an aerosol, be economically scalable, remain stable in the air, have a high virulence, and so on. The biological agent of choice will vary depending on the intended effect, be it to kill or incapacitate, contaminate terrain for long periods, trigger a major epidemic, or psychological impact.
Past biological weapon programs have researched and tested a large number of pathogens that eventually were not weaponised. Biological agents that were validated for biological weapons in past programs include those that cause anthrax, brucellosis, Q fever, tularaemia, Venezuelan equine encephalitis, glanders, plague, Marburg virus disease and smallpox.
These are all biological agents found in nature. Biological agents may also be enhanced from their natural state to make them more suitable for use as weapons, as was the case in some of the historical programs.
In future, biological agents might be completely unknown. DNA synthesis techniques, which synthesize DNA strands from off-the-shelf chemicals and assemble them into genes and microbial genomes, may enable the creation of bioengineered agents whose characteristics combine traits from a number of dangerous pathogens, or whose characteristics are entirely novel and possibly more deadly and communicable than those that exist in nature.
The delivery systems of biological weapons can also take a variety of forms. Past programs have constructed missiles, cluster bombs, and drones to deliver biological agents, as well as sprayers and spray-tanks to be fitted to aircraft, cars, trucks and boats. There have also been documented efforts to develop delivery devices for assassinations or sabotage operations, including a variety of sprays, brushes, and injection systems, as well as means for contaminating food and clothing.
Biowarfare programs can also come in all shapes and sizes, as they have done in the past, from the grandiose, resource-rich, high-tech ones to the small, almost primitive efforts funded on a limited budget.
The varied manifestations of biological weapons and BW programs can make them especially hard to detect. This problem is compounded by the fact that there are few aspects of a BW programme that are unique to offensive applications and that are readily detectable by outsiders.
This is unlike nuclear and chemical weapons. Nuclear weapon programs leave unique signatures during the development, production and testing process that can be detected atlong range. Chemical weapon programs require industrial-scale production facilities and large stockpiles of munitions to pose a significant military threat and these are visible to overhead reconnaissance systems. Of course biological weapons—such as munitions designed to disseminate biological agents—and biological defences—such as syringes filled with vaccine—can be readily distinguished when placed side by side, but the research, development, production and testing activities used to develop these capabilities are similar, if not identical, in many ways.
Key Biological Agents Validated for Biological Weapons in Past Programmes
Bacillus anthracis
Anthrax (G) is an acute infectious disease caused by B. anthracis. It was the first disease for which a microbial origin was established – by Robert Koch in 1876.
Inhalation anthrax, the most deadly form of anthrax, is characterised by flulike symptoms including a sore throat, fever, muscle aches and malaise. A brief improvement is followed by respiratory failure and shock, with meningitis also frequently developing.
Bacillus anthracis is one of the most feared BW agents. It can be easily disseminated, can result in high mortality rates, and has the potential for a major public health impact. Like other key biological agents, it can cause public panic and social disruption, and it requires special action for public health preparedness.
Yersinia pestis
Plague is one of the oldest recorded diseases, and caused by the bacterium Yersinia pestis.
There are two forms: classic bubonic plague and pneumonic plague. It is the latter, the inhalation form, that has been targeted in past bioweapons programmes.
Pneumonic plague is characterised by malaise, high fever, chills, headache and muscle pain. This is followed by septicemic shock, respiratory failure, and, often, death.
Yersinia pestis is a strong candidate for biological weapons because it is easy to culture and mass produce, and relatively easy to aerosolize.
Variola major
Smallpox is a highly contagious viral disease caused by the Variola virus (G). It was eradicated in 1980.
Smallpox is characterised by fever, severe headaches, and a rash consisting of small, solid, raised lesions. As the rash progresses the small lesions fill with fluid and become inflamed, pus-filled, blisterlike and typically extremely painful.
Variola major is another strong candidate for biological weapons because it is a hardy virus, highly infectious through the air, can survive explosive delivery, and causes a debilitating disease with high mortality.
Francisella tularensis
Tularemia is an infectious disease of small mammals caused by the bacterium Francisella tularensis.
In humans, pneumonic tularemia is characterised by fever, headaches, chills, cough, chest pain and difficulty breathing. Skin lesions and swollen lymph nodes also develop. Can be fatal.
Francisella tularensis is dangerous because it can be released as an aerosol to cause large tularemia epidemics in both human and animal populations at the same time. It is hardy, tolerant of cold temperatures, extremely infectious in humans, and persists in the environment in water, moist soil, hay, straw and decaying animal carcasses.
Brucella
Brucella bacteria (G) can infect humans through ingestion of contaminated milk or meat, as well as through broken skin.
Brucellosis occurs mostly in animals, particularly pigs, sheep, cattle and dogs. In humans, infection with flulike symptoms including fever, headache, chills and general malaise. Nausea, vomiting and diarrhea may develop. In a small number of cases, the disease affects the heart and nervous system.
Brucella is primarily viewed as an incapacitant or as antianimal disease to cause disruption in the agricultural sector.
Venezuelan equine encephalitis (VEE) virus
In nature, VEE normally exists in a rodent-mosquito cycle that causes human cases only sporadically in restricted localities. When mutations occur that allow the virus to replicate in horses, large-scale equine outbreaks occur that can kill thousands of horses, spread for hundreds of kilometers, and persist for years.
In humans, VEE displays considerable variation in severity. Some strains have signficant mortality and permanent neurological damage.
The virus (G) grows well in the lab and is highly infectious, but contemporary medicine indicates it is considerably less controllable than was believed during the period it served as a US biological agent.