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The oldest seen symptoms of smallpox were found on three mummies in Egypt. While we do not know specifically where smallpox came from, the earliest writing about it were found in China in the 4th Century BCE.
https://www.cdc.gov/smallpox/history/history.html

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The first known smallpox epidemic.

The smallpox epidemic of 1350 BC took place in what is now known as Turkey as well as Northern Africa. The epidemic contributed to the fall of the Hittite civilization. This is the first smallpox epidemic on record.

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Smallpox- The Triumph over the most Terrible of the Ministers of Death.pdf

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There were many different treatments tried to cure smallpox before the use of inoculation, all of which were unsuccessful. One of the ones tried by Dr. Sydenham was to keep his patients cold but giving them 12 small beers a day.

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People in China began making a pill that contained the fleas of cows. This would prevent smallpox and is the first known occurrence of oral vaccination. Variolation, however, was practiced long before this. Variolation involves deliberately infecting a person with a mild form of the disease in hopes they will become immune after their sickness, while vaccination is exposing someone to a benign form of a virus in the hopes they will be immune.

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Smallpox- The Triumph over the most Terrible of the Ministers of Death.pdf

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Inoculation, or the use of purposeful exposure to the smallpox, by putting it in cuts on arms was used as a way to save people. There were earlier practices of this in China, India, and Africa my snorting scabs of those who were infected.

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Small pox, because of its potency, was used by some as a biological weapon. Lord Jeffery Amherst of England would offer smallpox covered blankets to Native Americans to kill them off.

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Smallpox is believed to have first infected humans around the time of the earliest agricultural settlements some 12,000 years ago. No surviving evidence of it, however, predates the so-called New Kingdom of Egypt, which lasted from about 1570 B.C. to 1085 B.C.

A few mummies from that era contain familiar-looking skin lesions. Ramses V, for example, who ruled for roughly four years in the 12th century B.C., looks to have had the raised bumps on his face and body for which smallpox is named (it's derived from the Latin word for "spotted").

Moreover, an ancient Egyptian papyrus scroll briefly describes what could be smallpox, as do Hittite clay tablets. The Hittites, who lived in the Middle East, even accused the Egyptians of infecting them during a war between the two empires.

Many historians speculate that smallpox likewise brought about the devastating Plague of Athens in 430 B.C. and the Antonine Plague of A.D. 165 to 180, the later of which killed an estimated 3.5 million to 7 million people, including Emperor Marcus Aurelius, and hastened the decline of the Roman Empire.

At any rate, it reached Europe no later than the 6th century, when a bishop in France unmistakably described its symptoms-a violent fever followed by the appearance of pustules, which, if the patient survived, eventually scabbed over and broke off. By that time, the contagious disease, caused by the variola virus, had spread all across Africa and Asia as well, prompting some cultures to worship special smallpox deities.

In the Old World, the most common form of smallpox killed perhaps 30 percent of its victims while blinding and disfiguring many others. But the effects were even worse in the Americas, which had no exposure to the virus prior to the arrival of Spanish and Portuguese conquistadors.

Tearing through the Incas before Francisco Pizarro even got there, it made the empire unstable and ripe for conquest. It also devastated the Aztecs, killing, among others, the second-to-last of their rulers. In fact, historians believe that smallpox and other European diseases reduced the indigenous population of North and South America by up to 90 percent, a blow far greater than any defeat in battle.

Recognizing its potency as a biological weapon, Lord Jeffrey Amherst, the commander-in-chief of British forces in North America during the French and Indian War, even advocated handing out smallpox-infected blankets to his Native American foes in 1763.

Knowing that no one can contract smallpox twice, survivors of the disease were often called upon to try and nurse victims back to health. Throughout much of the last millennium, this involved herbal remedies, bloodletting and exposing them to red objects.

One prominent 17th-century English doctor realized that those who could afford care actually seemed to be dying at a higher rate than those who couldn't. Yet that didn't stop him from telling a smallpox-infected pupil to leave the windows open, to draw the bed sheets no higher than his waist and to drink profuse quantities of beer.

Far more effective was inoculation, also called variolation, which involved taking pus or powdered scabs from patients with a mild case of the disease and inserting them into the skin or nose of susceptible, healthy people. Ideally, the healthy people would suffer only a slight infection this way and, in so doing, would develop immunity to future outbreaks.

Some people did die, but at a much lower rate than those who contracted smallpox naturally. Practiced first in Asia and Africa, variolation spread to the Ottoman Empire around 1670 and then to the rest of Europe within a few decades. Its first proponent in the present-day United States was Cotton Mather, a Puritan minister best known for vigorously supporting the Salem witch trials. Benjamin Franklin, who lost a son to smallpox, was another early American supporter.

Variolation notwithstanding, smallpox continued wreaking havoc on princes and paupers alike. In the 17th and 18th centuries, it killed several reigning European monarchs, including Habsburg Emperor Joseph I, Queen Mary II of England, Czar Peter II of Russia and King Louis XV of France, as well as an Ethiopian king, a Chinese emperor and two Japanese emperors.

Queen Elizabeth I of England and U.S. President Abraham Lincoln also apparently contracted smallpox during their time in office, though they fortuitously lived to tell the tale. Meanwhile, in Europe alone, an estimated 400,000 commoners were succumbing to smallpox annually.

Finally, in 1796, English doctor Edward Jenner performed an experiment that would, in good time, cause the virus' downfall. By inserting pus from a milkmaid with cowpox, a disease closely related to smallpox, into the arms of a healthy 8-year-old boy and then variolating him to no effect, Jenner was able to conclude that a person could be protected from smallpox without having to be directly exposed to it. This was the world's first successful vaccine, a term that Jenner himself coined. He tried to get his results published by the prestigious Royal Society, only to be told not to "promulgate such a wild idea if he valued his reputation."

Persisting anyway, his vaccine gradually started catching on. The advantages over variolation were many. Unlike a variolated person, a vaccinated person could not spread smallpox to others. Moreover, the vaccine seldom left a rash and proved fatal in only the rarest of circumstances.

"Future generations will know by history only that the loathsome smallpox existed and by you has been extirpated," U.S. President Thomas Jefferson wrote to Jenner in 1806. The following year, Bavaria declared vaccination mandatory, and Denmark did the same in 1810.

Because the vaccine originally had to be transferred from arm to arm, its use spread slowly. It was also much less effective in tropical countries, where the heat caused it to quickly deteriorate. Nonetheless, one country after another managed to rid itself of the disease. The last reported U.S. case came in 1949.

Spurred by two new technological advances-a heat-stable, freeze-dried vaccine and the bifurcated needle-the World Health Organization then launched a global immunization campaign in 1967 with the goal of wiping out smallpox once and for all. That year, there were 10 million to 15 million cases of smallpox and 2 million deaths, according to WHO estimates. Yet just a decade later, the number was down to zero. No one has naturally contracted the virus since a Somali hospital worker in 1977 (though a laboratory accident in England did kill someone in 1978).

After searching far and wide for any remaining trace of smallpox, the WHO's member states passed a resolution on May 8, 1980, declaring it eradicated. "The world and all its peoples have won freedom from smallpox," the resolution stated, adding that this "unprecedented achievement in the history of public health ... demonstrated how nations working together in a common cause may further human progress."

Today, guarded laboratories in Atlanta and Moscow hold the only known stores of the virus. Some experts say these should be destroyed, whereas others believe they should be kept around for research purposes just in case smallpox somehow remerges.

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Take a look back at the history of the pernicious disease.

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A country doctor named Edward Jenner from England discovered that one could become immune to smallpox by contracting cowpox. This finding was seconded by his friend and fellow doctor, Henry Cline. By 1801, it was a widely used practice.

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In 1806, President Thomas Jefferson wrote a letter to Jenner praising him for his work. By 1810, Denmark and Bavaria made vaccination mandatory.

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Smallpox is believed to have first infected humans around the time of the earliest agricultural settlements some 12,000 years ago. No surviving evidence of it, however, predates the so-called New Kingdom of Egypt, which lasted from about 1570 B.C. to 1085 B.C.

A few mummies from that era contain familiar-looking skin lesions. Ramses V, for example, who ruled for roughly four years in the 12th century B.C., looks to have had the raised bumps on his face and body for which smallpox is named (it's derived from the Latin word for "spotted").

Moreover, an ancient Egyptian papyrus scroll briefly describes what could be smallpox, as do Hittite clay tablets. The Hittites, who lived in the Middle East, even accused the Egyptians of infecting them during a war between the two empires.

Many historians speculate that smallpox likewise brought about the devastating Plague of Athens in 430 B.C. and the Antonine Plague of A.D. 165 to 180, the later of which killed an estimated 3.5 million to 7 million people, including Emperor Marcus Aurelius, and hastened the decline of the Roman Empire.

At any rate, it reached Europe no later than the 6th century, when a bishop in France unmistakably described its symptoms-a violent fever followed by the appearance of pustules, which, if the patient survived, eventually scabbed over and broke off. By that time, the contagious disease, caused by the variola virus, had spread all across Africa and Asia as well, prompting some cultures to worship special smallpox deities.

In the Old World, the most common form of smallpox killed perhaps 30 percent of its victims while blinding and disfiguring many others. But the effects were even worse in the Americas, which had no exposure to the virus prior to the arrival of Spanish and Portuguese conquistadors.

Tearing through the Incas before Francisco Pizarro even got there, it made the empire unstable and ripe for conquest. It also devastated the Aztecs, killing, among others, the second-to-last of their rulers. In fact, historians believe that smallpox and other European diseases reduced the indigenous population of North and South America by up to 90 percent, a blow far greater than any defeat in battle.

Recognizing its potency as a biological weapon, Lord Jeffrey Amherst, the commander-in-chief of British forces in North America during the French and Indian War, even advocated handing out smallpox-infected blankets to his Native American foes in 1763.

Knowing that no one can contract smallpox twice, survivors of the disease were often called upon to try and nurse victims back to health. Throughout much of the last millennium, this involved herbal remedies, bloodletting and exposing them to red objects.

One prominent 17th-century English doctor realized that those who could afford care actually seemed to be dying at a higher rate than those who couldn't. Yet that didn't stop him from telling a smallpox-infected pupil to leave the windows open, to draw the bed sheets no higher than his waist and to drink profuse quantities of beer.

Far more effective was inoculation, also called variolation, which involved taking pus or powdered scabs from patients with a mild case of the disease and inserting them into the skin or nose of susceptible, healthy people. Ideally, the healthy people would suffer only a slight infection this way and, in so doing, would develop immunity to future outbreaks.

Some people did die, but at a much lower rate than those who contracted smallpox naturally. Practiced first in Asia and Africa, variolation spread to the Ottoman Empire around 1670 and then to the rest of Europe within a few decades. Its first proponent in the present-day United States was Cotton Mather, a Puritan minister best known for vigorously supporting the Salem witch trials. Benjamin Franklin, who lost a son to smallpox, was another early American supporter.

Variolation notwithstanding, smallpox continued wreaking havoc on princes and paupers alike. In the 17th and 18th centuries, it killed several reigning European monarchs, including Habsburg Emperor Joseph I, Queen Mary II of England, Czar Peter II of Russia and King Louis XV of France, as well as an Ethiopian king, a Chinese emperor and two Japanese emperors.

Queen Elizabeth I of England and U.S. President Abraham Lincoln also apparently contracted smallpox during their time in office, though they fortuitously lived to tell the tale. Meanwhile, in Europe alone, an estimated 400,000 commoners were succumbing to smallpox annually.

Finally, in 1796, English doctor Edward Jenner performed an experiment that would, in good time, cause the virus' downfall. By inserting pus from a milkmaid with cowpox, a disease closely related to smallpox, into the arms of a healthy 8-year-old boy and then variolating him to no effect, Jenner was able to conclude that a person could be protected from smallpox without having to be directly exposed to it. This was the world's first successful vaccine, a term that Jenner himself coined. He tried to get his results published by the prestigious Royal Society, only to be told not to "promulgate such a wild idea if he valued his reputation."

Persisting anyway, his vaccine gradually started catching on. The advantages over variolation were many. Unlike a variolated person, a vaccinated person could not spread smallpox to others. Moreover, the vaccine seldom left a rash and proved fatal in only the rarest of circumstances.

"Future generations will know by history only that the loathsome smallpox existed and by you has been extirpated," U.S. President Thomas Jefferson wrote to Jenner in 1806. The following year, Bavaria declared vaccination mandatory, and Denmark did the same in 1810.

Because the vaccine originally had to be transferred from arm to arm, its use spread slowly. It was also much less effective in tropical countries, where the heat caused it to quickly deteriorate. Nonetheless, one country after another managed to rid itself of the disease. The last reported U.S. case came in 1949.

Spurred by two new technological advances-a heat-stable, freeze-dried vaccine and the bifurcated needle-the World Health Organization then launched a global immunization campaign in 1967 with the goal of wiping out smallpox once and for all. That year, there were 10 million to 15 million cases of smallpox and 2 million deaths, according to WHO estimates. Yet just a decade later, the number was down to zero. No one has naturally contracted the virus since a Somali hospital worker in 1977 (though a laboratory accident in England did kill someone in 1978).

After searching far and wide for any remaining trace of smallpox, the WHO's member states passed a resolution on May 8, 1980, declaring it eradicated. "The world and all its peoples have won freedom from smallpox," the resolution stated, adding that this "unprecedented achievement in the history of public health ... demonstrated how nations working together in a common cause may further human progress."

Today, guarded laboratories in Atlanta and Moscow hold the only known stores of the virus. Some experts say these should be destroyed, whereas others believe they should be kept around for research purposes just in case smallpox somehow remerges.

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Take a look back at the history of the pernicious disease.

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Dr. Jenner found that by using the cowpox as to inoculate patients it seemed to become less potent. He found a method to increase the potency and that was enough to supply the vaccinations.

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The story of vaccines did not begin with the first vaccine-Edward Jenner's use of material from cowpox pustules to provide protection against smallpox. Rather, it begins with the long history of infectious disease in humans, and in particular, with early uses of smallpox material to provide immunity to that disease.

Evidence exists that the Chinese employed smallpox inoculation (or variolation, as such use of smallpox material was called) as early as 1000 CE. It was practiced in Africa and Turkey as well, before it spread to Europe and the Americas.

Edward Jenner's innovations, begun with his successful 1796 use of cowpox material to create immunity to smallpox, quickly made the practice widespread. His method underwent medical and technological changes over the next 200 years, and eventually resulted in the eradication of smallpox.

Louis Pasteur's 1885 rabies vaccine was the next to make an impact on human disease. And then, at the dawn of bacteriology, developments rapidly followed. Antitoxins and vaccines against diphtheria, tetanus, anthrax, cholera, plague, typhoid, tuberculosis, and more were developed through the 1930s.

The middle of the 20 th century was an active time for vaccine research and development. Methods for growing viruses in the laboratory led to rapid discoveries and innovations, including the creation of vaccines for polio. Researchers targeted other common childhood diseases such as measles, mumps, and rubella, and vaccines for these diseases reduced the disease burden greatly.

Innovative techniques now drive vaccine research, with recombinant DNA technology and new delivery techniques leading scientists in new directions. Disease targets have expanded, and some vaccine research is beginning to focus on non-infectious conditions such as addiction and allergies.

More than the science behind vaccines, these timelines cover cultural aspects of vaccination as well, from the early harassment of smallpox variolators (see the intimidation of a prominent minister described in the 1721 Boston Smallpox Epidemic entry) to the establishment of vaccination mandates, to the effect of war and social unrest on vaccine-preventable diseases. Edward Jenner, Louis Pasteur, and Maurice Hilleman, pioneers in vaccine development receive particular attention as well.

This timeline category holds nearly all of the entries for the subject-specific timelines. A few of the entries have been left out in order to provide a broad overview.

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The story of vaccines did not begin with the first vaccine-Edward Jenner's use of material from cowpox pustules to provide protection against smallpox. Rather, it begins with the long history of infectious disease in humans, and in particular, with early uses of smallpox material to provide immunity to that disease.

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Eradication Plan

The WHO came up with a plan to eradicate smallpox around the world. There was insufficient funding and it was not successful at first.

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Origin of Smallpox

The origin of smallpox is unknown. The finding of smallpox-like rashes on Egyptian mummies suggests that smallpox has existed for at least 3,000 years. The earliest written description of a disease like smallpox appeared in China in the 4 th century CE (Common Era). Early written descriptions also appeared in India in the 7 th century and in Asia Minor in the 10 th century.

Spread of Smallpox

Historians trace the global spread of smallpox to the growth of civilizations and exploration. Expanding trade routes over the centuries also led to the spread of the disease.

Highlights from History:

6th Century-Increased trade with China and Korea brings smallpox to Japan.

7th Century-Arab expansion spreads smallpox into northern Africa, Spain, and Portugal.

11th Century-Crusades further spread smallpox in Europe.

15th Century-Portugal occupies part of western Africa, bringing smallpox.

16th Century-European settlers and the African slave trade import smallpox into:

The Caribbean

Central and South America

17th Century-European settlers bring smallpox to North America.

18th Century-Explorers from Great Britain bring smallpox to Australia.

Early Control Efforts

Smallpox was a terrible disease. On average, 3 out of every 10 people who got it died. People who survived usually had scars, which were sometimes severe.

One of the first methods for controlling smallpox was variolation, a process named after the virus that causes smallpox (variola virus). During variolation, people who had never had smallpox were exposed to material from smallpox sores (pustules) by scratching the material into their arm or inhaling it through the nose. After variolation, people usually developed the symptoms associated with smallpox, such as fever and a rash. However, fewer people died from variolation than if they had acquired smallpox naturally.

The basis for vaccination began in 1796 when the English doctor Edward Jenner noticed that milkmaids who had gotten cowpox were protected from smallpox. Jenner also knew about variolation and guessed that exposure to cowpox could be used to protect against smallpox. To test his theory, Dr. Jenner took material from a cowpox sore on milkmaid Sarah Nelmes' hand and inoculated it into the arm of James Phipps, the 9-year-old son of Jenner's gardener. Months later, Jenner exposed Phipps several times to variola virus, but Phipps never developed smallpox. More experiments followed, and, in 1801, Jenner published his treatise "On the Origin of the Vaccine Inoculation." In this work, he summarized his discoveries and expressed hope that "the annihilation of the smallpox, the most dreadful scourge of the human species, must be the final result of this practice."

Vaccination became widely accepted and gradually replaced the practice of variolation. At some point in the 1800s, the virus used to make the smallpox vaccine changed from cowpox to vaccinia virus.

Global Smallpox Eradication Program

In 1959, the World Health Organization (WHO) started a plan to rid the world of smallpox. Unfortunately, this global eradication campaign suffered from a lack of funds, personnel, and commitment from countries, and a shortage of vaccine donations. Despite their best efforts, smallpox was still widespread in 1966, causing regular outbreaks across South America, Africa, and Asia.

The Intensified Eradication Program began in 1967 with a promise of renewed efforts. Laboratories in many countries where smallpox occurred regularly were able to produce more, higher-quality freeze-dried vaccine. Other factors that played an important role in the success of the intensified efforts included the development of the bifurcated needle, the establishment of a case surveillance system, and mass vaccination campaigns.

By the time the Intensified Eradication Program began in 1967, smallpox was already eliminated in North America (1952) and Europe (1953). Cases were still occurring in South America, Asia, and Africa (smallpox was never widespread in Australia). The Program made steady progress toward ridding the world of this disease, and by 1971 smallpox was eradicated from South America, followed by Asia (1975), and finally Africa (1977).

Last Cases of Smallpox

In late 1975, three-year-old Rahima Banu from Bangladesh was the last person in the world to have naturally acquired variola major. She was also the last person in Asia to have active smallpox. She was isolated at home with house guards posted 24 hours a day until she was no longer infectious. A house-to-house vaccination campaign within a 1.5-mile radius of her home began immediately. A member of the Smallpox Eradication Program team visited every house, public meeting area, school, and healer within 5 miles to ensure the illness did not spread. They also offered a reward to anyone who reported a smallpox case.

Ali Maow Maalin was the last person to have naturally acquired smallpox caused by variola minor. Maalin was a hospital cook in Merca, Somalia. On October 12, 1977, he rode with two smallpox patients in a vehicle from the hospital to the local smallpox office. On October 22, he developed a fever. At first healthcare workers diagnosed him with malaria, and then chickenpox. The smallpox eradication staff then correctly diagnosed him with smallpox on October 30. Maalin was isolated and made a full recovery. Maalin died of malaria on July 22, 2013, while working in the polio eradication campaign.

Janet Parker was the last person to die of smallpox. In 1978, Parker was a medical photographer at England's Birmingham University Medical School. She worked one floor above the Medical Microbiology Department where staff and students conducted smallpox research. She became ill on August 11 and developed a rash on August 15 but was not diagnosed with smallpox until 9 days later. She died on September 11, 1978. Her mother, who was providing care for her, developed smallpox on September 7, despite having been vaccinated two weeks earlier. An investigation suggested that Janet Parker had been infected either via an airborne route through the medical school building's duct system or by direct contact while visiting the microbiology corridor.

World Free of Smallpox

Almost two centuries after Jenner hoped that vaccination could annihilate smallpox, the 33 rd World Health Assembly declared the world free of this disease on May 8, 1980. Many people consider smallpox eradication to be the biggest achievement in international public health.

Stocks of Variola Virus

Following the eradication of smallpox, scientists and public health officials determined there was still a need to perform research using the variola virus. They agreed to reduce the number of laboratories holding stocks of variola virus to only four locations. In 1981, the four countries that either served as a WHO collaborating center or were actively working with variola virus were the United States, England, Russia, and South Africa. By 1984, England and South Africa had either destroyed their stocks or transferred them to other approved labs. There are now only two locations that officially store and handle variola virus under WHO supervision: the Centers for Disease Control and Prevention in Atlanta, Georgia, and the State Research Center of Virology and Biotechnology (VECTOR Institute) in Koltsovo, Russia.

Page last reviewed:

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smallpox (variola major and variola minor)

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A new, properly funded and organized eradication plan was in place. Many countries had to work together and there were many problems that slowed progress.

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A history of eradication-successes, failures, and controversies

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On May 8, 1980, the World Health Assembly endorsed a historic resolution, which declared "that the world and all its peoples have won freedom from smallpox". Smallpox was the first and, so far, the only human disease to have been eradicated.

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The last naturally occurring smallpox case was found in Somalia. There was another case in 1978 but that was the outcome of a lab accident.

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Smallpox is the only human disease that has been successfully eradicated.¹

Smallpox, an infectious disease caused by the variola virus was a major cause of mortality in the past, with historic records of outbreaks across the world. Its historic death tolls were so large that it is often likened to the Black Plague.

The eradication of smallpox is therefore a major success story for global health for several reasons: it was a disease that was endemic (and caused high mortality rates) across all continents; but was also crucial to advances in the field of immunology. The smallpox vaccine was the first successful vaccine to be developed.

In this entry we cover:

the historical and epidemiological context of smallpox disease [jump to section]

a global overview of the long-run data on smallpox cases and mortality rates [jump to section]

the global decline of smallpox and its eradication in 1977 [jump to section]

the journey through varioliation to vaccination that led to its eradication [jump to section]

the impact of smallpox vaccination on life expectancy [jump to section]

the estimated costs of and lives saved from smallpox eradication [jump to section].

All our charts on Smallpox

What is smallpox?

Smallpox is a disease that is caused by the variola virus. It is an infectious (also known as 'communicable') disease meaning it can spread from one person or animal to another, either directly or indirectly. The variola virus, however, infects only humans (meaning animals are unable to catch smallpox).

There are two types of variola viruses - variola major and variola minor - with the former type being a much more severe form.

Humans are infected with the variola virus by coming in touch with droplets of a smallpox-infected patient. A healthy person can become infected if they inhale fluid droplets from another infected individual (e.g. through coughing or sneezing).²

Symptoms

Smallpox is most known for a rash of pustules covering a patient's entire body. After being infected with the variola virus, patients usually had no symptoms for 10-14 days (an incubation period) and symptoms of a common cold for 2-3 days (unspecific symptoms).³

On average, it then took the rash 24 hours to cover the body and an additional three weeks for pustules to grow in size, form crusts and eventually fall off. A surviving patient would be marked for life with depigmented skin and scars in places where pustules had formed.

While an infection of the variola minor virus would lead to death with a probability of less than one percent, the case fatality rate of the variola major virus has been estimated to be around 30 percent.⁴

The specific way a smallpox infection would lead to a patient's death remains unclear.⁵

The Oxford Textbook of Medicine notes symptoms of prostration (total exhaustion), toxaemia (usually poisoned by bacterial toxins) and hypotension (low blood pressure) but the exact biological mechanism causing such symptoms are unknown.⁶

Death usually occurred 10 to 16 days after the onset of symptoms.⁷

If a patient successfully fought off the infection and survived, (s)he would never catch smallpox again. A side effect of the body's fight against the variola virus was that memory cells were produced that were able to quickly detect and activate killer cells for any variola viruses that a survivor encountered in the future.

There was never a treatment for smallpox. Once a person was infected it was impossible to treat them; one could only helplessly let the disease run its course. It might be possible that modern antiviral drugs would now allow a treatment of the disease if the disease still existed: The Centers for Disease Control and Prevention (CDC)⁸ now lists three antiviral drugs as potential treatment options, but since they have never been tested on infected humans, their effectiveness remains unknown.

Origins of smallpox

The origin of the variola virus and the time since when it infected humans are uncertain. The WHO⁹ considers two theories for its origin: either, humans were infected by a variola-like virus from rodents "16,000 or 68,000 years before present"¹⁰ or by a proto-variola mutated into the disease we now know as smallpox.

The fact that the variola virus has remained distinct from the other members of its orthopoxvirus family for 3,000 years makes the former hypothesis more likely than the latter.¹¹

Epidemiologists hypothesized the virus's origin by making use of the fact that it exclusively infected humans and therefore depended on a sufficiently large human population which could continuously provide new human hosts for it to survive (infected humans either die or recover and become immune for life). Egypt hosted one of the earliest concentrations of human civilization along the River Nile about 3,000 years ago, making it a likely candidate for the origin of the continued existence of various infectious diseases, including smallpox and polio.

This hypothesized origin was supported by archeologists finding "dome-shaped vesicles [...] similar to those found in smallpox"¹²on three mummies whose skin, bones and muscles were preserved thanks to the Egyptian mummification practice. One of these was Pharaoh Ramses V who died in 1157 BCE. The photograph of his skull below clearly shows small pustules, especially on his cheeks. At the time of the mummy's discovery, electron microscopy was unfortunately not yet available. This analysis would have allowed for a definite diagnosis; authorities have not allowed investigators to extract tissue samples from the mummies since then.¹³

Ramses V is believed to be the first known victim of smallpox after examining the pustules found on his cheeks.¹⁴

How many died of smallpox?

In his review paper 'The eradication of smallpox - An overview of the past, present, and future' Donald Henderson reports that during the 20th century alone "an estimated 300 million people died of the disease."¹⁵

In his book Anderson suggests that in the last hundred years of its existence smallpox killed "at least half a billion people."¹⁶ 500 million deaths over a century means 5 million annual deaths on average.

Long-run smallpox deaths in Europe

The graph shows the deaths per 1000 citizens from over the long-run, dating from 1774 to 1900 in European countries for which data was available. Two phenomena are illustrated here. First, Swedish data which pre-dates an effective means against smallpox (in 1796) shows the large disease burden and endemicity of smallpox in the 18th century. In peak years, up to 7 out of 1000 Swedes died of smallpox and the volatile nature of outbreaks is a symptom of a disease being endemic (explained in our section on epidemiological definitions further below).

Second, it can be seen that among selected countries, those that had adopted vaccination legislation earlier saw their smallpox death rates decrease more substantially and suffered fewer casualties during the Franco-Prussian War of 1870/71. Austria and Belgium, both of which never made smallpox vaccination mandatory, still recorded large numbers of smallpox deaths from 1875 onwards whereas other European countries displayed had already driven down smallpox fatalities significantly by then.

Nevertheless, smallpox was still endemic in every European country at the end of the 19th century.

Number of smallpox cases

The chart depicts the number of smallpox cases by country, for most countries dating 1920 until 1977. Here we see that by the time the World Health Organization (WHO) launched its Intensified Smallpox Eradication Program in 1966, most countries in Western Europe and North America had almost eliminated smallpox whilst the countries across South America, Africa and Asia, especially India, still recorded very large numbers (note the large differences in color brackets below).

Global data on the number of smallpox cases is shown in the chart. Shown here is the number of reported smallpox cases worldwide from 1920 until the last case in 1977. Just the reported number of smallpox cases between 1920 and 1978 already amounted to 11.6 million cases; and that number was certainly smaller than the actual number of cases, although we do not know by how much. Even though smallpox had a high visibility and should therefore be relatively easy to document, the lack of an international organization dedicated to global health means the number of reported cases is probably substantially lower than the true number of cases. Crosby (1993) estimates that in 1967 10-15 million people were still being infected with smallpox every year while the chart on the reported cases below indicates only 132,000 for that same year.¹⁷

The reasons and extent of discrepancies between reported and estimated cases are discussed in our section on Data Quality.

The chart shows global case numbers (as shown in the section above) disaggregated by world region, extending to 1977, the year of the last case globally.

Even though absolute numbers are almost certainly far too low (as explained above and in our section on Data Quality), it can be seen that in relative terms, South Asia had by far the highest number of smallpox cases. This was primarily driven by incidence in India: in 1973, for instance, in a state that had reported approximately 500 cases a week, the WHO search team found 10,000 cases.¹⁸

Eradication of smallpox

The last variola major infection was recorded in Bangladesh in October 1975, and the last variola minor infection occurred two years later in Merka, Somalia, on October 26th, 1977. During the following two years, WHO teams searched the African continent for further smallpox cases among those rash-like symptoms (which is a symptom of numerous other diseases). They found no further cases.

In 1978, a laboratory accident in the United Kingdom occurred where a variola virus sample was spread through the university laboratory's ventilation system, infecting two people and killing one.¹⁹

The world map shows the year in which each country recorded the last endemic case of smallpox. Europe, North America and Australia managed to eliminate smallpox relatively early, most by the 1940s (predating the WHO's Intensified Smallpox Eradication Program, which was launched in 1966). Countries across Sub-Saharan Africa, Latin America and Asia eliminated smallpox several decades later in the 1960s and 70s.

In May 1980, the World Health Assembly, the governing body of the World Health Organization, officially certified the global elimination of smallpox, the first ever eradication of a disease in human history. It further "recommended that all countries cease vaccination, all laboratories should destroy their remaining stocks or transfer them to" two certified high security laboratories in Moscow (State Research Center of Virology and Biotechnology) or the Centers for Disease Control and Prevention (CDC) in Atlanta.²⁰

These are the only two known places that still hold samples of the variola viruses for research purposes.

Variolation

Variolation (sometimes also inoculation), refers to the deliberate transmission of viral matter.

Before the year 1000, Indians and the Chinese had already observed that contraction of smallpox protected children against any future outbreaks of the disease. As a consequence they developed a procedure that involved the nasal inhalation of dried smallpox scabs by three-year-olds.²¹

Another commonly practiced technique (whose geographic and temporal origin are unknown) encompassed the injection of the liquid found inside the pustules of a smallpox patient underneath the skin of a healthy person. This would usually result in a milder infection of smallpox after which the person was immune against the disease. Both practices became known as variolation (inoculation) techniques.

The disadvantage of variolation, however, was that during the course of the mild infection the person became a carrier of the disease and could infect other people. Additionally, it was difficult to control the severeness of the infection which sometimes developed into a full-blown smallpox case that could lead to the person's death.²²

This meant that the practice usually reduced the severeness of an infection and the likelihood of deaths but that it would never lead to eliminating the virus. If anything, it helped to spread the virus in a population even further and thereby encouraged its survival.

A British ambassador's wife, Lady Mary Wortley Montague (1689-1762) was the force that pushed for government-mandated variolation in England. She herself had suffered a smallpox infection and lost her younger brother to the disease at the age of 26. She first learned about variolation when she arrived in Istanbul in 1717, where variolation was commonly practiced. She later had the embassy inoculate her two children.

News spread among the royal family and after following trials Maitland successfully inoculated the two daughters of the Princess of Wales in 1722. Thereafter, variolation became a common practice in Great Britain and became known in other European countries. It became an even more established practice when the French King Louis XV died of smallpox in May of 1776 and his successor and grandson Louis XVI was inoculated with the variola virus one month later.

Vaccine against smallpox

At the end of the 18th century British surgeon and physician Edward Jenner (1749-1823) pioneered the first ever vaccination against an infectious disease. He himself had been inoculated with smallpox at the age of 8 and later as a surgeon, variolation was part of his work.²³ He observed that people who had suffered from cowpox would subsequently have a very mild, if at all visible reaction to the smallpox variolation. At the time unknowingly, he had discovered that the cowpox and variola viruses were members of the same orthopoxvirus family.

He hypothesized that variolation using the cowpox virus would protect children against smallpox as well. Since cowpox infections were much milder and never fatal, this would eliminate the problem of variolated children being carriers of smallpox and sometimes dying of the virus developing into a full-blown infection. On top of protection against the symptoms, it could reduce the stock of humans that the variola virus needed for survival and brought elimination and eventually eradication of smallpox into the realm of possibility.

In May 1796, Jenner inoculated a boy with cowpox, and then a few months later with the smallpox virus. When the boy did not develop any smallpox symptoms in response to being variolated, his hypothesis of the cowpox offering protection from smallpox was confirmed motivating his further research trials.

Initially, Jenner faced major barriers to spreading the word about his discovery. When he submitted a paper outlining his findings to the journal Philosophical Transactions edited by the Royal Society, it was rejected. They even advised him not to pursue his ideas any further, pointing to the detrimental impact on his career and reputation. Undeterred, he published his work with an increased number of trials at his own expense two years later (in 1798). He also went on to convince colleagues and supply them with vaccines in other British cities of his new procedure that became known as vaccination (derived from the Latin word for cow, vacca).

By 1802, the British Parliament did acknowledge his important contribution and awarded him £30,000. Meanwhile, vaccination had spread to most of Europe and New England.²⁴

His 1798 publication Inquiry into the Variolae vaccinae known as the Cow Pox had been translated into German, French, Spanish, Dutch, Italian, and Latin within three years. US President Thomas Jefferson figured importantly in the widespread application of vaccination throughout the United States and in 1806, he thanked Edward Jenner in a letter for his discovery and famously predicted "Future generations will know by history only that the loathsome smallpox existed and by you has been extirpated."²⁵

The dramatic decline in smallpox fatalities in response to Jenner's vaccine can be traced in the chart, which shows the number of deaths due to smallpox as a share of all deaths in London from 1629 to 1902. Before the introduction of a smallpox vaccine in 1796, on average 7.6% (1-in-13) of all deaths were caused by smallpox. Following introduction of the vaccine, we see a clear decline in smallpox deaths.

Smallpox Eradication Program

It was only with the establishment of the World Health Organization (WHO) in the aftermath of World War II that international quality standards for the production of smallpox vaccines were introduced. This shifted the fight against smallpox from a national to international agenda. It was also the first time that global data collection on the prevalence of smallpox was undertaken.

By 1959, the World Health Assembly, the governing body of the World Health Organization (WHO) had passed a resolution to eradicate smallpox globally. It was not until 1966, however, that the WHO provided the 'Intensified Smallpox Eradication Program' with funding to increase efforts for smallpox eradication.

By 1966, the number of infections of smallpox had already substantially been reduced by national governments' efforts. Nonetheless, skepticism about the feasibility of eradication prevailed and the WHO lacked experience in administering projects that required both technical and material support, as well as coordination across countries. Furthermore, the funding provided to the Intensified Smallpox Eradication Programme was insufficient to meet global needs, resulting mostly in vaccine shortages.²⁶

Further still, continued globalization and growth of international air travel resulted in the continual re-introduction of the disease into countries that had previously managed to eliminate smallpox.

Overcoming the last mile problem: ring vaccination

Smallpox's eradication was greatly spurred by making use of the fact that smallpox transmission occurs via air droplets. Initially, the WHO had pursued a strategy of mass vaccination which attempted to vaccinate as many people as possible, hoping that herd immunity (explained in our vaccine entry) would protect the whole population. Soon, however, vaccination efforts were targeted locally around smallpox cases as smallpox was transmitted by sick patients' air droplets. This is known as the ring vaccination principle.

People who had been in direct contact with a smallpox patient over the last two weeks were quarantined and vaccinated. The downside of such an approach was that the virus could spread easily if it was re-introduced from overseas. This was the case in Bangladesh, for example, which had previously eliminated smallpox until 1972 when it was brought back from across its border with India.²⁷

Despite the risk of re-introductions, ring vaccination greatly reduced the cost of the eradication campaign. The number of administered vaccines dropped and smallpox was increasingly brought under control. Regional elimination came within reach.²⁸

One of the last strongholds of the variola virus was India. While 57.7 percent of global reported smallpox cases were reported in India in 1973, this increased to 86.1 percent in 1974.²⁹ One major push in vaccination campaigns, however, successfully drove down the number of infections to zero in India in 1976.

Impact on life expectancy

Did smallpox variolation and vaccination against smallpox have a notable impact on life expectancy?

Many have made the claim that inoculation against smallpox was one of the first measures that had a positive effect on life expectancy. Angus Deaton (2013) makes this claim based on a book by Razzell (1977), which reviews existing birth, baptism and burial records in various counties of 18th century Britain.³⁰ ³¹ Whilst some anecdotal evidence suggests smallpox deaths declined over the course of the 18th century, we cannot be sure that the spread of inoculation practices were the cause of that decline. Furthermore, the local communities for which records were available may not have been representative of Great Britain as a whole. Such evidence therefore seems insufficient to show a causation relationship between inoculation and increases in life expectancy.

It is hard to prove such claims because of the lack of and low quality of data on both life expectancy and smallpox cases/deaths prior to the invention of Jenner's vaccine in 1796. Whilst we have presented data on smallpox deaths in London dating back to 1629, we only know the aggregate life expectancy of Great Britain (rather than London specifically) over this period. It's unlikely that London's smallpox deaths are nationally representative which means that the direct comparison is not possible.

When comparing these charts on London smallpox deaths and British life expectancy we see that neither smallpox deaths or life expectancy dramatically deviated from their averages following the wider adoption of variolation in 1722.

But can we say something about the impact of Jenner's vaccination on life expectancy? The high case fatality rate of approximately 30 percent (for the variola major virus strand) meant that smallpox shortened the lives of many. Since the virus predominantly affected children during endemic periods, smallpox deaths are likely to have had a disproportionate impact on average life expectancy.

The chart visualizes Sweden's life expectancy (in red) and deaths from smallpox (in blue) from 1774 to 1900. Large-scale smallpox outbreaks were documented for the years 1779, 1784, 1789, 1795 and 1800. These years exactly coincide with sharp declines in life expectancy, implying that smallpox endemicity did have a substantial effect on life expectancy. Furthermore, while the available data did not show a clear decline in smallpox deaths after the introduction of inoculation in Britain, they do show dramatic declines in mortality in London as well as in Sweden (below) from 1800 onwards. Once smallpox mortality fell at the turn of the eighteenth to nineteenth century, life expectancy in Sweden for the first time was put on an upwards trending trajectory.

Overall, the impact of inoculation on life expectancy remains uncertain. Jenner's vaccine appears to have had a notable impact on increased life expectancy but this, to our knowledge, has not been studied in significant detail.³²

Costs of smallpox and its eradication

By the time the World Health Organization launched the Intensified Smallpox Eradication Program in 1967 many countries, most of them high income countries, had already eliminated smallpox. Therefore, the true cost of eradicating smallpox will never be known as individual country programs reach back to before records of public health expenditure existed. Nonetheless, the Intensified Smallpox Eradication Program has been estimated to have cost $300 million in total from 1967 to 1977³³ with one-third of the funding provided by international donors and the remaining two-thirds financed by endemic country governments.³⁴

Beyond direct program costs, smallpox incurred much higher indirect costs in the form of foregone economic performance. It has been estimated that smallpox cost low-to-middle income countries more than $1 billion per year at the beginning of the Intensified Smallpox Eradication Program in 1967, with more than $20 million dedicated to the care of infected patients.³⁵

Industrialized countries incurred much lower costs: $350 million in 1968 which included vaccination programs and absence from work costs.³⁶

Overall, the Center for Global Development³⁷ estimated that direct and indirect costs of smallpox cost the world approximately $1.35 billion in the late 1960s.

Following its eradication, countries now do not have to spend money on vaccine development and administration. Estimates on the savings from forgone costs thanks to the eradication of smallpox exist, but we are not aware of estimates that we would consider reliable.³⁸

Lives saved from smallpox eradication

To date the eradication of smallpox saved millions of lives. It is impossible to know very exactly how many people would have died of smallpox since 1980 if scientists had not developed the vaccine, but reasonable estimates are in the range of around 5 million lives per year, which implies that between 1980 and 2018 around 150 to 200 million lives have been saved.³⁹

Epidemiological definitions/context

The origin of the naming of smallpox and the variola virus
The name of smallpox originates from a common confusion with syphilis in 15th century France. The diseases shared similar symptoms (rashes) even though syphilis was caused by spirochaete bacteria and smallpox by the variola virus. Syphilis had already been known as variola, so smallpox became known as la petite vérole. Petite is French for small so the disease became known as smallpox in English.

The name of the variola virus, in turn, can be derived from the Latin words varus (pimple) or varius (changing color) which derive from smallpox's symptoms described above.⁴⁰

The variola virus family tree
The variola virus is a member of the so-called orthopoxvirus family, whose other members are the vaccinia, cowpox and monkeypox viruses.⁴¹

This is important as Jenner's vaccine used the cowpox virus, a much milder and not lethal disease, to protect humans against smallpox. The variola virus is the family's only virus that exclusively infects humans.

The variola virus consists of two strands, known as the variola major and variola minor viruses. Infections of the variola major strand led to a patient's death in approximately 30% of cases, whereas the variola minor virus proved lethal in only less 1% of infections.⁴²

Eradication is the "permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts".⁴³

Elimination refers to the "reduction to zero of the incidence of infection caused by a specific agent in a defined geographic area as a result of deliberate efforts." A disease can be eliminated from a specific region without being eradicated.⁴⁴

Infectious Diseases are "disease[s] caused by the entrance into the body of organisms (as bacteria, protozoans, fungi, or viruses) which grow and multiply there".⁴⁵

Variolation refers to the deliberate transmission of viral matter, for example by inserting material from an infected person's skin underneath a healthy person's skin.⁴⁶

Endemic refers to the constant presence [...] of a disease in a population within a geographic area.⁴⁷

Endemic vs. non-endemic populations
The severity and most common age group for smallpox infections was dependent on whether the virus was endemic in a population. If a population had never been exposed to smallpox before, all age groups were vulnerable to infection, meaning outbreaks led to high case and death rates across the population. McMillan (2016)⁴⁸

terms this a 'virgin soil epidemic', i.e. when a disease touches "soil" it has never touched before. The most prominent example of smallpox attacking an unprotected and never-exposed population in history is the introduction of the variola virus in North America by British colonialists. Data on the deaths of Native American tribes suffered were unfortunately not collected at the time but available sources agree that tribes were substantially decimated.⁴⁹

Regularity and severity
In an endemic population, on the other hand, smallpox outbreaks with large numbers of cases and deaths usually occurred only every two to four years. In the periods between large outbreaks, the disease would persist at lower levels of incidence (with lower numbers of cases and deaths).

Such a pattern is common among viral diseases in an endemic population: by the time the virus had infected a population, an outbreak either engendered immunity or death, so a renewed outbreak in a subsequent year would infect fewer people.⁵⁰

These cyclical outbreaks can be observed in the volatile pattern of the smallpox share in London deaths and also the smallpox death rates across Europe.

Age profile of patients
Smallpox could infect people of any age. However, when the virus was endemic in a society (uninterrupted transmission without depending on re-introduction from elsewhere), it mainly infected children. Adults in an endemic population would have been infected with the virus at an earlier stage in their lives already and since the only two possible outcomes of an infection were death or survival and life-long immunity, the virus could only infect and be transmitted by individuals that had never been exposed before: children.

In 17th century Britain, this led to children not being considered full members of the family until they had survived their smallpox infection. At the time, the British had not yet come up with a protection against smallpox so children were almost guaranteed to fall prey to an infection and families could do nothing but watch the infection run its course and hope the child would survive.⁵¹

Why are there differences between reported and estimated cases?

Three main reasons are responsible for the huge differences between reported and the estimated (thought to be closer to the truth) number of cases and deaths due to smallpox. First, many infections and deaths were not recorded simply because the monitoring public health system was dysfunctional and that was predominantly the case in developing countries where the disease burden was highest. Fenner et al. (1988) write: "It is clear that the reporting of cases of smallpox was the most efficient in countries in which the health services were well developed, which was usually where the disease was least common. It was very inefficient elsewhere."⁵²

Second, classifying deaths posed another challenge. For instance if smallpox patients had already been suffering from pneumonia or even just a flu when becoming infected with smallpox and then died, it is unclear whether smallpox or pneumonia or the flu were the cause of death. Had a patient survived the smallpox infection if (s)he had not already been weakened by another disease, this creates a major challenge in classifying the cause of deaths which is likely to have further diminished the number of smallpox cases and deaths actually reported and recorded.

Third, some anecdotes suggest that some smallpox outbreaks were deliberately kept secret.⁵³

Razzell (1977) writes in his book about British market towns: "Many tradesmen in market towns may have suppressed information about smallpox in their families and certainly the townspeople as a whole were very anxious to avoid advertising the presence of smallpox in their own town so as to avoid frightening country people from the surrounding area - there are many examples of markets being ruined for more than a year because of the presence of smallpox."⁵⁴

Extent of reporting discrepancy

The World Health Assembly was aware of the underreporting and therefore attempted to correct the number of reported smallpox cases upward for the years 1959 to 1966, just before the Intensified Smallpox Eradication Program was launched. The chart illustrates that the corrections were highest for 1965, where the originally reported smallpox cases only amounted to 64,000 cases which was corrected to almost double its value, 112,000 cases.

Many sources suggest, however, that even these corrections were small in comparison to what the actual extent of smallpox's disease burden was. Fenner et al. (1988) write "it is not unreasonable to regard the official figures reported to WHO as representing only 1-2 percent of the true incidence - probably nearer 1 percent for the years before the initiation of the global eradication programme. In the early 1950s, 150 years after the introduction of vaccination, there were probably some 50 million cases of smallpox in the world each year, a figure which had fallen to perhaps 10-15 million by 1967."⁵⁵

These figures are also mentioned in the final report by the WHO that confirmed smallpox's eradication, along with the disease still causing approximately 2 million deaths in 1967.⁵⁶

Henderson (1976) adds that the global cases numbers reported to the WHO in 1967 probably were the number of infections taking place in northern Nigeria alone.⁵⁷

In 1973, the World Health Organization conducted a thorough search for smallpox cases in line with its ring vaccination strategy in India: in a state that had reported approximately 500 cases a week the search team found 10,000 cases.⁵⁸

Data: Global number of smallpox cases

Geographical coverage: Global (total)

Time span: 1920-2016

Available at: Link under the data tab at the right on the Earth Policy Institute's website here.

Data: The year of the last recorded smallpox case and the reported number of smallpox cases

Geographical coverage: Global (by country)

Time span: Year of the last recorded smallpox case: 1910-1977
Reported number of smallpox cases: 1886-1966

Available at: Chapter 8 of Fenner, F., Henderson, D., Arita, I., Jezek, Z., & Ladnyi, I. (1988). Smallpox and its eradication. Geneva: World Health Organization. Fully available for download here.

Data: The reported number of smallpox cases

Geographical coverage: Global (by country)

Time span: 1967-1977

Available at: Archived Weekly Epidemiological Records available on the WHO website but the links to the relevant decades at the bottom of the list are unfortunately dysfunctional. Therefore, the search function at the top right was used and search times such as "Weekly Epidemiological Record 1970" were used. Direct links to the individual volumes used for graphs on this entry can be found under the "Sources" tab of the graph The number of reported smallpox cases.

Data: The number of deaths caused by smallpox as a share of all deaths

Geographical coverage: London

Time span: 1629-1902

Available at: The Guy (1882) paper is available on JSTOR here. For detailed information on which data sources we used in addition to Guy (1882), click on the Sources tab at the bottom of our graph for individual years' references.

Data: The number of smallpox deaths per 1,000 (living) population

Geographical coverage: Austria, Belgium, England, Netherlands, Prussia, Scotland, Sweden

Time span: 1774-1900

Available at: Edwardes (1902) A concise history of small-pox and vaccination in Europe. H.K. Lewis. Available online here.

Further reading recommendations

S.L. Kotar and J.E. Kessler's novel Smallpox: A history

Christian W. McMillen's Pandemics: A very short introduction

Jonathan B. Tucker's Scourge: The Once and Future Threat of Smallpox

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Smallpox is the only human disease that has been successfully eradicated.1 Smallpox, an infectious disease caused by the variola virus was a major cause of mortality in the past, with historic records of outbreaks across the world. Its historic death tolls were so large that it is often likened to the Black Plague.

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After eradication efforts around the world, smallpox was ended. Months later, the WHO officially confirmed it had been eradicated.

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The World Health Organization commemorated the 40th anniversary of smallpox eradication today, recognizing the historic moment on 9 December 1979 when the end of smallpox was confirmed to have been eradicated. Five months later, in May 1980, the 33rd World Health Assembly issued its official declaration that 'the world and all its peoples have won freedom from smallpox'.

A plaque marking the end of a scourge that had afflicted millions for thousands of years was unveiled at WHO headquarters in Geneva in the very same meeting room where, four decades earlier, the 19 members of the Global Commission for the Certification of Smallpox Eradication certified that smallpox had been eradicated from the world.

Speaking at the event attended by country representatives, UN representatives and WHO staff who worked on smallpox, WHO Director-General Tedros Adhanom Ghebreyesus said, "Today, smallpox is the only human disease ever eradicated, a testimony to what we can achieve when all nations work together.

"When it comes to epidemic disease, we have a shared responsibility and a shared destiny. With this plaque, we commemorate the heroes around the world who came together to fight smallpox and worked to keep future generations safe."

Until it was wiped out, smallpox had plagued humanity for at least 3000 years, killing 300 million people in the 20th century alone. The last known endemic case of smallpox was reported and the outbreak promptly contained in Somalia in 1977.

The successful smallpox eradication programme yielded vital knowledge and tools for the field of disease surveillance, the benefits of ring vaccination and the importance of health promotion in fighting diseases such as poliomyelitis and the Ebola virus. It also laid the foundation for stronger national immunization programmes worldwide, underpinning the establishment of primary health care in many countries and creating momentum toward Universal Health Coverage.

Today's commemoration kicks off a year-long campaign in which WHO and partners will mark the eradication of smallpox and raise awareness about the need to continue the fight against polio and other diseases and accelerate investments in global health security. A smallpox eradication exhibition will be unveiled at the World Health Assembly in May 2020 and is expected to travel to other events, including the United Nations General Assembly in New York.

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WHO commemorates the 40th anniversary of smallpox eradication

# data[].attributes.attachment_link.description
The World Health Organization commemorated the 40th anniversary of smallpox eradication today recognizing the historic moment on 9 December 1979 when the end of smallpox was confirmed to have been eradicated. Five months later, in May 1980, the 33rd World Health Assembly issued its official declaration that 'the world and all its peoples have won freedom from smallpox'.

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Smallpox samples are known to exist in two labs: one in the USA and one in Russia. Smallpox is still considered a threat to public safety and continues to be researched.

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Smallpox, caused by the variola virus, was a highly contagious infectious disease that caused infected individuals to develop a fever and a progressive, disfiguring skin rash. Three of out 10 individuals infected with smallpox died. Many survivors have permanent scars, often on their faces, or were left blind. Through vaccination, the disease was eradicated in 1980. However, research for effective vaccines, drugs and diagnostics for smallpox continues in the event it is used as a bioterror weapon.

The last naturally occurring case of smallpox was reported in 1977. In 1980, the World Health Organization declared that smallpox had been eradicated. Currently, there is no evidence of naturally occurring smallpox transmission anywhere in the world. Although a worldwide immunization program eradicated smallpox disease decades ago, small quantities of smallpox virus officially still exist in two research laboratories in Atlanta, Georgia, and in Russia.

Why Is the Study of Smallpox a Priority for NIAID?

Smallpox is a category A pathogen which are those organisms/biological agents that pose the highest risk to national security and public health because they can be easily disseminated or transmitted from person to person, result in high mortality rates and have the potential for major public health impact, might cause public panic and social disruption, and require special action for public health preparedness.

How Is NIAID Addressing This Critical Topic?

NIAID supports basic, preclinical, and clinical research needed to advance product development for biodefense and emerging infectious diseases. Product development goals in this arena have shifted from a "one bug-one drug" approach to a more flexible strategy that is applicable to a broad spectrum of infectious diseases. Specifically, this broad-spectrum approach is being used to develop products effective against a variety of pathogens and toxins; find technologies that can be widely applied to improve multiple classes of products; and establish platforms that can reduce the time and cost of creating new products. This is evident in both the treatment and vaccine research NIAID has supported for smallpox, outlined below.

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Smallpox, caused by the variola virus, was a highly contagious infectious disease that caused infected individuals to develop a fever and a progressive, disfiguring skin rash. Three of out 10 individuals infected with smallpox died. Many survivors have permanent scars, often on their faces, or were left blind.