The World’s Deadliest Biological Weapons


As mentioned in our list of the 10 deadliest chemical weapons, humans love to find new and terrifying ways of destroying each other. Biological warfare dates as far back as 1155 CE when Emperor Barbarossa poisoned the water supply of his enemies with human bodies, but the foundation of microbiology opened up a whole host of terrifying possibilities for deadly pathogens and delivery methods that will give you nightmares.

From anthrax envelopes, deadly bacteria, to vicious RNA superbugs, and hemorrhagic fever inducing viruses, here are ten of the deadliest biological weapons known to humankind. 

10. Anthrax

Anthrax is a naturally occurring bacterium called Bacillus anthracis that can cause severe illness in both animals and humans, though it is rare in the Americas and is thought to have evolved in Egypt—being responsible for the fifth plague as told in the Bible. The deadly bacterium was first weaponized in World War I by the German army. They started by secretly infecting the animal feed and livestock of neutral nations who traded with the Allies. 

After the horrors of biological and Chemical warfare in World War I, the use of such agents on the battlefield was greatly limited or banned by the Geneva Protocol. This served to curtail the use of biological weapons but didn’t specifically ban the research and production of them.

In 1932, the Japanese attacked 11 Chinese cities with anthrax and other biological weapons. Their primary method of delivery was generating sprays from aircraft directly onto enemy homes.

The most recent case of anthrax used as a weapon was in 2001 when 22 people were infected with contaminated envelopes. Of the 22 infected, seven were postal workers, and a total of five people died as a result of the attack.

Victims of an anthrax attack can expect to experience small groupings of itchy blisters, swelling around those blisters, and painless skin ulcers that feature a black center. Other symptoms include chest discomfort, fever, chills, confusion, dizziness, cough, nausea, vomiting, stomach pains, headaches, extreme exhaustion, and full-body aches. 

9. Botulism

Botulism is one of the deadliest toxins in the world. While it is relatively rare to find someone that has developed botulism naturally, the Center for Disease Control and the World Health Organization recognizes its potential to be used as a biological weapon. About 200 people a year are diagnosed with botulism, and none of those cases have so far been linked to bioterrorism. The symptoms, however, can be quite severe. It starts with the muscles in the face becoming paralyzed, and if left untreated, that paralysis can spread to the rest of the body, even shutting down the muscles used for breathing. Typically, if the disease is caught early and properly diagnosed, fewer than five out of 100 people die from it. 

But just because an attack hasn’t happened yet, doesn’t mean someone won’t weaponize it in the future, and the toxin is impossible to see, smell, or taste. Even small doses can make someone extremely sick, and some patients end up hospitalized for months.

8. Variola

Known by some as “the Red Plague,” variola or “smallpox” was a highly contagious disease that caused high fever, head and body aches, a severe rash, and pustules to cover the body of an infected person. With a mortality rate of 30% in adults and a much higher death rate in babies, variola was no small matter. Fortunately, the disease was wiped out in 1980 by the World Health Organization.

However, there are two labs on Earth that have direct access to the disease for research purposes, the Center for Disease Control in the United States, and the Russian State Center for Research on Virology and Biotechnology in the Russian Federation. The World Health Organization is concerned that a country or a terrorist organization may use the disease as a bioweapon in the future, and intelligence suggests that smaller countries have developed secret stashes of smallpox. It’s also feared that those supplies have been lost over time, falling into the hands of various terrorist organizations.

You might be thinking, “So what? There’s a vaccine for it!” and while that’s certainly true, the last real case of smallpox occurred in 1975, and since then vaccination campaigns have all but vanished (except for a brief resurgence in the early 2000s, following the 9/11 attacks)—the vaccine also doesn’t result in lifetime immunity from the disease. Because of this, an entire generation has grown up without immunity to smallpox, leaving us all potentially vulnerable if it were to be weaponized in the future.

7. Q Fever

It’s a disease caused by the bacteria Coxiella burnetii. The bacterium occurs naturally and infects animals such as sheep, cows, and goats, causing their byproducts (milk, feces, and even placenta) to become contaminated. Most people who ingest Coxiella burnetii do not develop symptoms, but symptoms are typically flu-like in those that do. 

Even though those infected with Q fever aren’t very contagious, the US and the Soviet Union developed mass quantities of a weaponized version of the bacteria. The weaponized variety is highly infectious, and human trials proved extremely successful as all those who volunteered to become infected with the disease developed symptoms. Testing of Q fever went on for two decades in the US, with those volunteering being primarily Seventh Day Adventists, who wished to serve their country without wielding weapons.

As recently as 2006, the Center for Disease Control placed restrictions on the research conducted at Texas A&M’s facilities after it was discovered that three researchers had contracted the disease, and not reported it to the CDC (as is dictated by law). The information was obtained by a biosafety group through the Freedom of Information Act.

It’s worth it to note that even the weaponized variant of Q fever is treatable with antibiotics. 

6. Tularemia

Initially thought to be a plague similar to the Black Death when it was first observed in 1911, Tularemia is considered to be one of the most dangerous bacteria ever discovered, and a prime candidate to be harvested into a biological weapon, because of its worldwide abundance. Its true scientific name is Francisella tularensis, a non-spore-forming bacterium which, if left untreated in humans, can lead to a deadly disease. 

Known in some parts as rabbit fever or deer fly fever because of its tendency for infecting mammals, especially rodents, rabbits, and hares, it was one of the many biological weapons experimented with by the Japanese in the ’40s, and stockpiled by the US government in the ’60s. 

Even though it’s not known for human to human spread, governments still fear its use as a biological weapon. This is in part because of the myriad of ways in which it could be spread; whether it be from tick or deer fly bites, skin contact with the infected, drinking contaminated water, inhaling contaminated dust or aerosols, or even laboratory exposure.  

Strangely enough, the symptoms caused by the bacterium depend on where it enters the patient’s body. If caused by a tick or fly bite, an ulcer can form around the bite, followed by the swelling of lymphatic nodes around the affected area, sometimes in the armpit or groin of the patient. If it enters through the eye, the tissue and lymphatic nodes around the patient’s eye can become inflamed. If ingested, it can lead to mouth ulcers and swelling of lymph nodes in the neck. The most serious form of infection is when it’s breathed in as a dust or aerosol, causing severe cough, chest pains, and difficulty breathing. 

5. Bunyavirus

Not just one, but a family of 300 viruses, Bunyaviridae are single-strand enveloped RNA viruses that rarely infect humans and livestock. But, when infection does occur, it’s usually through arthropod bites such as fleas, ticks, and flies. Bunyaviridae cause what’s known as hemorrhagic fever, and while it’s rare for humans and animals to become infected in nature when distilled down into an aerosol form, Bunyaviridae and related viruses become extremely stable.

The potential for Bunyaviridae for biological warfare was first conducted by the former Soviet Union. 

Viral hemorrhagic fever can cause a range of symptoms, including fever, rash, and hemorrhaging. What’s dangerous about these types of infections is that the entire vascular system is damaged, and multiple organs are affected at once. In some cases, this leads to relatively mild symptoms, but in others, it can lead to potentially life-threatening illness. Because Bunyaviridae are not widely common in many parts of the world, a biological attack in a country where the virus isn’t common can have dire consequences on the ecosystem, and the people who live there.

4. Cholera

Despite advances in medical technology, cholera infections still cause 2,000 to 6,000 deaths each year since the beginning of the new millennium. It’s caused by a bacterium, which typically gets into water supplies, infecting everyone who drinks it. 

As many as seven pandemics have been caused by this bacterium

The Japanese studied how to weaponize it and dropped it on Chinese cities, resulting in over 10,000 infected. But among the dead were 1,700 Japanese soldiers, highlighting how difficult it is to protect against its spread. 

As a disease, cholera is particularly deadly, causing severe diarrhea and dehydration. If it isn’t caught, it can be fatal in hours.

Though it has all but been eradicated in the US, it still exists in undeveloped countries. 

3. Marburg Virus

With a mortality rate of 88%, Marburg virus is one of the deadliest diseases on Earth. Discovered in 1967 after an outbreak linked to the study of African green monkeys in Marburg and Frankfurt, the disease resembles Ebola in shape, and folds into a U, or 6-shaped spiral, though it is antigenically different from that disease. The virus is also highly contagious, only requiring person to person contact for spread to occur.

After incubating in a patient’s body for 5-10 days, symptoms such as fever, chills, headache, and myalgia manifest. These symptoms persist for about five days, at which point the patient experiences maculopapular rash, nausea, vomiting, chest pain, sore throat, abdominal pain, and diarrhea. From here, symptoms continue in severity, possibly leading to jaundice, inflammation of the pancreas, severe weight loss, delirium, shock, liver failure, massive hemorrhaging, and multiple-organ failure. 

In order to determine its viability as a bioweapon, the Soviet Union dispersed the virus over groups of monkeys in aerosol form, and determined that infection resulted even with very few virions (the term for virus particles outside a host body). As a result of this testing, Marburg virus is a class A bio-warfare agent. After the accidental exposure of Dr. Ustinov, the lead scientist working on the virus, the Soviets harvested a particularly deadly version of it from his corpse. This version of the virus, called Marburg Virus U, was meant to be loaded into guided warheads or used in conjunction with other delivery methods. 

The Center for Disease Control is still concerned about the potential harvesting of Marburg virus as a biological weapon.

2. Aflatoxins

Aflatoxins are found in molds that primarily grow on various types of nuts. Although deaths as a result of poisoning from aflatoxins are limited to undeveloped countries, they’re still particularly dangerous to humans. Prolonged exposure to these toxins can lead to severe health problems, and even liver cancer. 

But what makes them an effective bioweapon is the fact that they don’t function like a pathogen. Toxins can be dispersed in an area through various means like aerosol, poisoning the water supply, and even contaminating crops. 

A high dose of an aflatoxin will most often cause liver failure, leading the victim to experience jaundice, lethargy, and nausea before finally succumbing to the toxin.

1. Ebola 

Primarily found in sub-Saharan African countries, Ebola is especially deadly in humans and primates. It’s believed that patients can become infected with Ebola by coming into contact with contaminated blood, bodily fluids (including feces), and animal tissues. Bats and primates are thought to be the primary source of the outbreaks which have historically been confined to the African continent. 

Symptoms of the virus can manifest anywhere from two to 21 days after exposure, starting with fever, aches, pains, and fatigue, followed by diarrhea, vomiting, rash, impaired kidney and liver function, blood in their stool, low white blood cell counts, and internal and external bleeding.

Since Ebola has a 90% deathrate in those infected, it has been suggested that it would be a particularly nasty biological weapon. While it is possible to make an “Ebola bomb” the work required to weaponize the virus would be extremely dangerous. There are only four category four laboratories capable of safe handling of the virus on Earth, and if a terrorist organization were to transport the virus to a lab that wasn’t up to par, it’s more than likely that they would end up infecting themselves. So, you probably don’t have to worry about countries harvesting this one as a bioweapon anytime soon, as the virus is extremely sensitive to environmental changes (unlike anthrax), not to mention, obtaining an infected animal with the virus is extremely difficult. 

Still, if someone were able to successfully harvest it as a weapon, it would be especially deadly. Let’s hope that never happens.

Other Articles you Might Like
Liked it? Take a second to support on Patreon!

Leave A Reply

two × three =

This site uses Akismet to reduce spam. Learn how your comment data is processed.