Home » Module 4: Anthrax » Anthrax and Smallpox: The New Weapons of Mass Destruction

Anthrax and Smallpox: The New Weapons of Mass Destruction

Color-enhanced scanning electron micrograph shows splenic tissue from a monkey with inhalational anthrax; featured are rod shaped bacilli (yellow) and an erythrocyte (red).
Color-enhanced scanning electron micrograph shows splenic tissue from a monkey with inhalational anthrax; featured are rod shaped bacilli (yellow) and an erythrocyte (red).

Bacteria, viruses, parasites – over the last few units, we have seen a world that appears filled with disease-causing pathogens. However, now there are increasing fears that pathogens are in line to replace traditional bombs as an agent of warfare and terrorism. Although the government has responded with much research spending on bioterrorism countermeasures, how does one defend against a bioterrorism attack or even prepare troops to confront agents of biological warfare on the battlefield? While vaccination programs might seem a simple answer, the reality is more complicated. Such immunological defenses, as well as pharmacological measures, are an important topic of consideration for today’s policy makers. We’ll consider such policies in this unit, along with two disease agents that highlight the fears of biological weaponry: anthrax and smallpox.


Foundations of Biological Weaponry and Terror

The most direct definition of biological warfare is given in a NATO handbook:

“. . . employment of biological agents to produce casualties in man or animals or damage to plants.”2,3

Of course, this does not explain why anyone would want to make a weapon out of a virus or bacterium. What advantages would such a biological agent have over a traditional bomb?

First, biological weapons are inexpensive. According to the same NATO report, a biological weapon can kill half the population of a square kilometer area for about $1.00. [Though this figure dates to 1969, even inflation would not raise it appreciably in relation to other forms of weaponry]2. Also, unlike traditional bombs, biological weapons specifically attack living organisms, avoiding damage to a city’s infrastructure (and the consequent economics costs of reconstruction)2. Additionally, a biological weapon can act like a slow-ticking bomb. For example, a terrorist group could deposit a biological weapon in a water supply and exit harm’s way as the ensuing epidemic might take months to develop2.

Making a “biobomb”

In most cases, the steps involved in making a biological weapon are frighteningly straightforward. Essentially, all that is required is:

1. A biological agent. Typically acquired from the environment or a laboratory, such agents can be made through the use of molecular biology. For example, a toxin producing gene can be inserted into a normally benign bacterium, making it deadly. Additionally, such agents can sometimes be made from historical samples as seen with the resurrection of the 1918 flu virus and the recent synthesis of the polio virus5,6.

2. Large amounts of the biological agent. Once the agent has been acquired and/or sufficiently purified from contaminants, it has to be grown into large supplies. Bacteria and fungi are usually cultured in media on plates or in flasks, while viruses can be grown in chick embryos (similarly to how vaccine stock is generated). In addition, these large quantities of the agent must be packaged to avoid leaks that would harm the messenger. Bacteria, viruses, and other pathogens usually have optimal conditions for causing disease, including temperature, wind (if air dispersal is necessary), light, or person-to-person contact4. Freeze-drying is a common treatment as many pathogens are inactive at low temperature4.

Many of the techniques involved in the creation of a biological weapon have been developed and refined in biomedical laboratories for decades. A bacterium is a bacterium, after all, and the same tools that are used to devise new cures can also help create terrible weapons. This very issue has led to much recent debate over “dual-use” research, where a technology can be both beneficial and harmful depending upon its use (see Case Study).

What Counts as a Biological Weapon?

There are a wide range of pathogens than can be “weaponized”. In the wake of 9/11, researchers have attempted to more carefully define “high-risk” pathogens deserving particular attention7-9. Under their criteria, a “maximally credible threat” would be highly lethal, overwhelm healthcare and treatment resources, and generally instill panic. Rising to the top of this list were anthrax and smallpox – the two pathogens we will take a closer look in this module.