Variola virus
Missing image

Micrograph of the smallpox virus

Template:Taxobox begin placement virus Template:Taxobox group i entry

Species:Variola virus

|} Smallpox (also known by the Latin names Variola or Variola vera) is a highly contagious disease unique to humans. It is caused by two virus variants called Variola major and Variola minor. V. major is the more deadly form, with a typical mortality of 20-40 percent of those infected. The other type, V. minor, only kills 1% of its victims. Many survivors are left blind in one or both eyes from corneal ulcerations, and persistent skin scarring - pockmarks - is nearly universal. Smallpox was responsible for an estimated 300-500 million deaths in the 20th century. As recently as 1967, The World Health Organization (WHO) estimated that 15 million people contracted the disease and that two million died in that year.

After successful vaccination campaigns, the WHO in 1979 declared the eradication of smallpox, though cultures of the virus are kept by the Centers for Disease Control and Prevention (CDC) in the United States and at the Institute of Virus Preparations in Siberia, Russia. Smallpox vaccination was discontinued in most countries in the 1970s as the risks of vaccination include death (~1 per million), among other serious side effects. Nonetheless, after the 2001 anthrax attacks took place in the United States, concerns about smallpox have resurfaced as a possible agent for bioterrorism. As a result, there has been increased concern about the availability of vaccine stocks. Moreover, President George W. Bush has ordered all American military personnel to be vaccinated against smallpox and has implemented a voluntary program for vaccinating emergency medical personnel.

Famous victims of this disease include Ramesses V (see Koplow, p. 11, plus notes), Shunzhi Emperor of China (official history), Mary II of England, Louis XV of France, and Peter II of Russia. Henry VIII's fourth wife, Anne of Cleves, survived the disease but was scarred by it, as was Henry VIII's daughter, Elizabeth I of England in 1562 and Abraham Lincoln in 1863.

Missing image
A smallpox victim.

After first contacts with Europeans and Africans, the death of a large part of the native population of the New World was caused by Old World diseases. Smallpox was the chief culprit. On at least one occasion, germ warfare was attempted by the British Army under Jeffrey Amherst when two smallpox-infected blankets were deliberately given to representatives of the besieging Delawares Indians during Pontiac's Rebellion in 1763. That Amherst intended to spread the disease to the natives is not doubted by historians; whether or not the attempt succeeded is a matter of debate.[details]

Smallpox is described in the Ayurveda books. Treatment included inoculation with year-old smallpox matter. The inoculators would travel all across India pricking the skin of the arm with a small metal instrument using "variolous matter" taken from pustules produced by the previous year's inoculations. The effectiveness of this system was confirmed by the British doctor J.Z. Holwell in an account to the College of Physicians in London in 1767.

Edward Jenner developed a smallpox vaccine by using cowpox fluid (hence the name vaccination, from the Latin vacca, cow); his first inoculation occurred on May 14, 1796. After independent confirmation, this practice of vaccination against smallpox spread quickly in Europe. The first smallpox vaccination in North America occurred on June 2, 1800. National laws requiring vaccination began appearing as early as 1805. The last case of wild smallpox occurred on September 11th, 1977. One last victim was claimed by the disease in the UK in September 1978, when Janet Parker, a photographer in the University of Birmingham Medical School, contracted the disease and died. A research project on smallpox was being conducted in the building at the time, though the exact route by which Ms. Parker became infected was never fully elucidated.



Transmission is by droplets, and infection in the natural disease will be via the lungs. The incubation period to obvious disease is around 12 days. In the initial growth phase the virus seems to move from cell to cell, but around the 12th day, lysis of many infected cells occurs and the virus will be found in the bloodstream in large numbers. The initial or prodromal symptoms are essentially similar to other viral diseases such as influenza and the common cold - fevers, muscle pain and stomach aches etc. The digestive tract is commonly involved, leading to vomiting. Most cases will be prostrated.

Smallpox virus preferentially attacks skin cells and by days 14-15, smallpox infection becomes obvious. The attack on skin cells causes the characteristic pimples associated with the disease. The pimples tend to erupt first in the mouth, then the arms and the hands, and later the rest of the body. At that point the pimples, called macules, should still be fairly small. This is the stage at which the victim is most contagious.

By days 15-16 the condition worsens - at this point the disease can take two vastly different courses. The first form is of classical ordinary smallpox, in which the pimples grow into pauples, and then fill up with pus (turning them into pustules). Ordinary smallpox generally takes one of two basic courses. In discrete ordinary smallpox, the pustules stand out on the skin separately - there is a greater chance of surviving this form. In confluent ordinary smallpox, the blisters merge together into sheets which begin to detach the outer layers of skin from the underlying flesh - this form is usually fatal. If a victim of ordinary smallpox survives for the course of the disease, the pustules will deflate in time (the duration is variable), and will start to dry up, usually beginning on day 28. Eventually the pustules will completely dry and start to flake off. Once all of the pustules flake off, the patient is considered cured.

In the other form of smallpox, known as haemorrhagic smallpox, an entirely different set of symptoms starts to develop. The skin does not blister, but remains smooth. Instead, bleeding will occur under the skin, making the skin look charred and black (this is known as black pox). The eyes will also haemorrhage, making the whites of the eyes turn deep red (and, if the victim lives long enough, eventually black). At the same time, bleeding begins in the organs. Death may occur from bleeding (fatal loss of blood or by other causes such as brain haemorrhage), or from loss of fluid. The entry of other infectious organisms, since the skin and intestine are no longer a barrier, can also lead to multi-organ failure. This form of smallpox occurs in anywhere from 3-25% of fatal cases (depending on the virilence of the smallpox strain).



Several historical plagues are believed by some historians to have been early outbreaks of smallpox. But contemporary records are not detailed enough to make a definite diagnosis at this distance. Other historians suggest bubonic plague, measles or other epidemic diseases may have been responsible.

The Plague of Athens decimated the city of Athens in 430 BCE, killing around a third of the population, according to Thucydides. Historians have long considered this an example of bubonic plague, but more recent examination of the reported symptoms led some scholars to believe this disease was either measles or smallpox.

The Antonine Plague that swept through the Roman Empire and Italy in 165180 is also thought to be either smallpox or measles. A second major outbreak of disease in the Empire, known as the Plague of Cyprian (251266), was also either smallpox or measles.

The next major epidemic believed to be smallpox occurred in India. The exact date is unknown. Around 400, an Indian medical book recorded a disease marked by pustules, saying "the pustules are red, yellow, and white and they are accompanied by burning pain … the skin seems studded with grains of rice." The Indian epidemic was thought to be punishment from a god, and the survivors created a goddess to honor the disease. In Hinduism the goddess Sitala both causes and cures high fever, rashes, hot flashes and pustules. All of these are symptoms of smallpox.

Smallpox did not enter Europe until about 581. Most of the details about the epidemic that followed are lost, probably due to the scarcity of written records and the general lack of social order in the European Dark Ages.

The Americas

In 1519 Hernán Cortés landed on the shores of what is now Mexico and was then the Aztec empire. After he landed, one of the most famous coincidences in history took place. The Aztecs were expecting the arrival of a white-skinned god with yellow hair, Quetzalcoatl. Cortes had yellow hair and white skin and thus was received as a god, and was allowed to rule accordingly. In 1520, another group of Spanish came from Cuba and landed in Mexico. Among them was an African slave who had smallpox. When Cortes heard about the other group, he went and defeated them. In this contact, one of Cortes's men contracted the disease. When Cortes returned to Tenochtitlán, he brought the disease with him.

Soon the Aztecs realized that Cortes was not a god and rose up in rebellion. Outnumbered, the Spanish were forced to flee. In the fighting, the Spanish soldier carrying smallpox died. After the battle, the Aztecs evidently looked on the invaders' bodies for riches and contracted the virus. Cortes would not return to the capital until August 1521. In the meantime smallpox was devastating the Aztec population. It killed most of the Aztec army, the emperor, and 25% of the overall population. A Spanish priest left this description: "As the Indians did not know the remedy of the disease...they died in heaps, like bedbugs. In many places it happened that everyone in a house died and, as it was impossible to bury the great number of dead, they pulled down the houses over them so that their homes become their tombs." On Cortes' return, he found the Aztec army's chain of command in ruins. The soldiers who lived were still weak from the disease. Cortes then easily defeated the Aztecs and entered Tenochtitlán, where he found that smallpox had killed more Aztecs than had the cannons. The Aztecs said that they could not walk though the streets without stepping on the bodies of smallpox victims.

The effects of smallpox on Tahuantinsuyu (or Inca empire) were even more devastating. Beginning in Colombia, smallpox spread rapidly before the Spanish invaders first arrived in the empire. The spread was probably aided by the efficient Inca road system. Within months, the disease had killed the Sapa Inca Huayna Capac, his successor, and most of the other leaders. Two of his surviving sons warred for power and, after a bloody and costly war, Atahualpa become the new Sapa Inca. As Atahualpa was returning to the capital Cuzco, Francisco Pizarro arrived and through a series of deceits captured the young leader and his best general. Within a few years smallpox claimed between 60% and 90% of the Inca population, with other waves of European disease weakening them further.

Even after the two mighty empires of the Americas were defeated by the virus, smallpox continued its march of death. North America was next. In 1633 in Plymouth, Massachusetts, the Native Americans were struck by the virus. As it had done elsewhere, the virus wiped out entire population groups of Native Americans. It reached Lake Ontario in 1636, and the lands of the Iroquois by 1679, killing millions. The worst sequence of smallpox attacks took place in Boston, Massachusetts. From 1636 to 1698, Boston endured six epidemics. In 1721 the most severe epidemic occurred. The entire population fled the city, bringing the virus to the rest of the 13 colonies. In the late 1770s, during the American Revolutionary War, smallpox returned once more and killed an estimated 125,000 people.Template:Ref

See: Population history of American indigenous peoples for a discussion of this disease and other issues at the time of European contact.


By that time, a preventive treatment for smallpox had finally arrived. It was a process called inoculation, also known as insufflation or variolation. Inoculation was not a sudden innovation, as some practices had been around for centuries. The Chinese blew powdered smallpox scabs up the noses of the healthy. The patients would then develop a mild case of the disease and from then on were immune to it. The process spread to Turkey, where an American doctor learned of it. He then told the Royal Society in England, where Lady Mary Wortley Montagu learned of it. She began to get other people interested in inoculation. When no one listened, she tried it on her son and daughter, aged 5 and 4 respectively. They both recovered quickly and the procedure was hailed as a success.

In 1721, an epidemic of smallpox hit London and left the British Royal Family in fear. When they read about the success of Lady Wortley Montagu's efforts, they wanted to use inoculation on themselves. Doctors told them that it was a dangerous procedure, so they decided to try it on other people first. The subjects they used were condemned prisoners. The doctors inoculated the prisoners and all of them recovered in a couple of weeks. So assured, the British royal family inoculated themselves and reassured the English people that it was safe.

But inoculation still had its critics. Prominent among them were religious preachers who claimed that smallpox was God's way of punishing people and that inoculation was a tool of Satan. This resistance only encouraged Montagu and the others to work even harder. By 1723 inoculations were extremely common in England.

In 1721, Onesimus (Oh-NES-ih-mus) was the slave of a Boston preacher when smallpox came to Boston via a ship arriving from Barbados.Template:Ref His owner, Cotton Mather asked his slave if he ever had smallpox. Onesimus said, "Yes and no," and explained a technique from his homeland in Africa, thought to be in Sudan. He explained that pus from an infected person was deliberately rubbed into a scratch or cut of a non-infected person, and when successful, the person had immunity. This remedy from an African-American slave was the precursor to inoculations. Cotton Mather, the son of a former Harvard University dean, was waging a campaign of his own to promote the process, although religious resistance to inoculation was very strong. At one point, Cotton Mather was in danger from a crowd that wanted to hang him. After six patients died from the procedure, he was called a murderer. But, when the population of Boston returned after the end of a smallpox epidemic in 1722, he was an instant hero. Out of the population of Boston, 7% had died from smallpox. Out of the 300 people that chose to inoculate themselves, only 2% died. By 1774, it was considered odd not to choose inoculation. Onesimus was later freed by Mather, not for his knowledge and help in combating smallpox, but because Mather considered him to be disobedient.

Even though inoculation was a powerful method of controlling smallpox, it was far from perfect. Inoculation caused a mild case of smallpox which resulted in death in about 2% of the cases. It was also difficult to administer. Sick patients had to be locked away to prevent them from transmitting the disease to others. In 1757, a young boy in England by the name of Edward Jenner was inoculated. He suffered from the disease for an entire month. Even though he recovered, he was determined to find a better method of preventing smallpox.


At the age of thirteen, young Jenner was apprenticed to a doctor. He observed that people who caught cowpox while working with cows were known not to catch smallpox. He assumed a causal connection. The idea was not taken up by Dr. Ludlow at that time. After Jenner returned from medical school in London, a smallpox epidemic struck his home town of Berkeley, England. He advised the local cow workers to be inoculated. The farmers told him that cowpox prevented smallpox. This confirmed his childhood suspicion, and he studied cowpox further.

In 1796 Sarah Nelmes, a local milkmaid, contracted cowpox and went to Jenner for treatment. Jenner took the opportunity to test his theory. He inoculated James Phipps, the eight year-old son of his gardener, not with smallpox but with cowpox. After an extremely weak bout of cowpox, James recovered. Jenner then tried to infect James with smallpox but nothing happened — the boy was immune to smallpox.

Jenner reported his observations to the Royal Society. The initial reception was cool. Jenner repeated the process with five more children, one of them his son Edward. It worked on all of them. After this he was taken seriously, and by 1800 Jenner's work had been published in all of the major European languages. The process was performed all over Europe and the United States. The death rate was close to zero with the process, which became known as vaccination.

The Balmis Expedition (1803) carried the vaccine to Spanish America, the Philippines and China under commission of the Spanish Crown.

Some years before Dr. Jenner, Benjamin Jesty, a farmer from Yetminster in Dorset (he later moved to and is buried at Worth Matravers) is recorded as observing the two milkmaids living with his family to have been immune to smallpox and then inoculating his family with cowpox to protect them from smallpox. This has never been adequately verified, however, and the question of who first initiated smallpox inoculation/vaccination has not been settled to this day.

Louis T. WrightTemplate:Ref, an African-American and Harvard medical school graduate in 1915, introduced intradermal vaccination for smallpox for the soldiers while serving in the Army during WWI.Template:Ref


Jenner said, "The annihilation of smallpox - the dreadful scourge of the human race - will be the final result of vaccination." Jenner's dream was ultimately realized. Around the world, attempts would be made to annihilate smallpox. In 1842, England banned inoculation and ordered everyone to get vaccinated instead. In the United States, from 1843 to 1855, different states started requiring all students to be vaccinated. Not everyone liked this requirement, however. Many people said that the government was crossing a line by ordering people to get vaccinated. Despite the complaints, the war against smallpox went on and the disease was disappearing quickly in the wealthy countries.

However, in poorer countries such as Somalia and India, vaccines were unaffordable and sometimes unknown. The final effort to attain the noble goal first set by Jenner would not begin until 1958, when the Soviet Union called for the eradication of smallpox from the planet. At that point, 2 million people were dying every year. In 1967, an international team of doctors was placed under the leadership of an American, Donald Henderson. For the eradication plan to work properly, the team needed to find cases of smallpox when they were erupting, so that they could vaccinate everyone who lived close by. This process is known as ring vaccination. The idea was cheaper and easier to implement than a process to vaccinate everyone who lived on the planet. The team ran into problems right away. They found that 95% of all smallpox victims do not report to the authorities.

Instead of rushing to where smallpox was occurring, they were forced to deploy a network of experts around the world. When the disease emerged, local governments (whether they were willing or not) were rallied to vaccinate everyone in the area.

The project would have failed, if not for the sheer heroism displayed by many of the experts involved. All of them knew that failure was not acceptable. The world would never have devoted so many resources to defeat this disease unless it were imperative that smallpox be wiped out.

But smallpox fought tenaciously and did not give ground easily. In India and Bangladesh, religion and around-the-clock civil wars became huge obstacles. In fear of offending the goddess associated with the disease, many Hindus refused the vaccine. Undeterred, the team simply vaccinated them against their will. Civil war ended up being a bigger problem. The nature of war means that troops are often moved from place to place and lodge in crowded tents or barracks, an ideal condition for spreading smallpox. The soldiers then spread the disease to villagers, who then disperse it further.

The team's answer to civil war was to vaccinate all the troops, with or without the permission of generals commanding the armies. The team placed themselves in great danger by doing this, and the WHO even told them to stop. Surprisingly, none of the team members were hurt in the process.

Nature, unfortunately, also impeded the vaccination team's efforts. Just as the team was on the brink of success, the monsoon rains came, bursting dams and dikes. The rain and flooding forced people to flee, once again allowing smallpox to spread. This outbreak took the team a whole year to stop.

The last major European outbreak of smallpox was the 1972 outbreak of smallpox in Yugoslavia. After a pilgrim returned from the Middle East, where he had contracted the virus, an epidemic infected 175 people with 35 deaths. Authorities declared martial law, enforced quarantine and undertook massive revaccination of the population, enlisting the help of the WHO and Donald Henderson. In two months, the outbreak was over.

The last naturally occurring case of Variola Minor was diagnosed on October 26, 1977. The last naturally occurring case of the more deadly Variola Major was detected two years earlier in November 1975. It had cost a mere 300 million United States dollars to eradicate smallpox.


In 1978, there was evidently an escape of smallpox from containment in a research laboratory in Birmingham, England. A medical photographer, Janet Parker, died from the disease itself, and the Professor responsible for the unit killed himself. In light of this accident, all known stocks of smallpox were destroyed, except the stocks at the United States Center for Disease Control (CDC) and the Vector Institute in Koltsovo, Novosibirsk in Siberia, where a regiment of troops guard it. Under such tight control, smallpox would, it was thought, never be let out again. Even though the destruction of virus stocks was ordered in 1993, 1994, 1995, and 1996, they have not yet been destroyed. There apparently remain a number of researchers who still wish to retain the stocks for scientific purposes.

It is also feared that additional stocks of the virus may exist in research collections, the product of the accumulatory nature of microbiologists. Additional collections of the virus almost certainly exist as the result of certain military and biological warfare programs, such as the Soviet State Research Center of Virology and Biotechnology (also known as Vector) labs, which maintained stocks separate from those held by the Moscow Institute for Viral Preparation.

In March 2003 Smallpox scabs were found tucked inside an envelope in a book on Civil War medicine in Santa Fe, New Mexico. The envelope was labeled as containing the scabs and listed the names of the patients that were vaccinated with them. Assuming the contents could be dangerous, the librarian who found them did not open the envelope. This was fortunate, as, unlike bacteria (with the exception of those that produce spores), viruses can theoretically survive for many years. The scabs ended up with employees from the National Centers for Disease Control, who responded quickly once informed of the discovery. The discovery raised concerns that smallpox DNA could be extracted from these and other scabs and used for a biological attack. However, the chances of successfully doing that are very slim according to experts.

See also


  • Fenner, Frank, Henderson, D.A., Arita, Isao, Jezek, Zdenek, and Ladnyi, Ivan D. "Smallpox and Its Eradication." World Health Organization (WHO), Geneva, Switzerland, 1988. ISBN 9241561106.
  • Hopkins, Donald R. "Princes and Peasants: Smallpox in History." University of Chicago Press, Chicago, IL, 1983. ISBN 0226351777.
  • Koplow, David. "Smallpox: The Fight to Eradicate a Global Scourge." University of California Press, Berkeley and Los Angeles, CA, 2003, ISBN 0-520-23732-3.
  • McNeill, William H. "Plagues and Peoples." Bantam Doubleday Dell Publishing Group, Inc., New York, NY, 1976, ISBN 0-385-12122-9.

Numbered references

  1. Template:Note Fenn, Elizabeth Anne (2001). Pox Americana: The Great Smallpox Epidemic of 1775-82 (1st edition). Hill and Wang. ISBN 0809078201.
  2. Template:Note Willoughby, Brian (Feb 12, 2004). BLACK HISTORY MONTH II: Why Wasn't I Taught That? ( Availability verified 2005-03-02.
  3. Template:Note A Brief Biography of Dr. Louis T. Wright ( hosted as part of the Great Migration Project ( Availability verified 2005-03-03.
  4. Template:Note Spotlight on Black Inventors, Scientists, and Engineers (,%20Scientists,%20and%20Engineers.htm) hosted by the Department of Computer Science of Georgetown University ( Availability verified 2005-03-03.

External link

cs:Neštovice de:Pocken es:Viruela eo:Variolo fr:Variole he:אבעבועות שחורות nl:Pokken ja:天然痘 no:Kopper pl:Ospa prawdziwa pt:Varíola sk:Kiahne fi:Isorokko sv:Smittkoppor zh:天花


  • Art and Cultures
    • Art (
    • Architecture (
    • Cultures (
    • Music (
    • Musical Instruments (
  • Biographies (
  • Clipart (
  • Geography (
    • Countries of the World (
    • Maps (
    • Flags (
    • Continents (
  • History (
    • Ancient Civilizations (
    • Industrial Revolution (
    • Middle Ages (
    • Prehistory (
    • Renaissance (
    • Timelines (
    • United States (
    • Wars (
    • World History (
  • Human Body (
  • Mathematics (
  • Reference (
  • Science (
    • Animals (
    • Aviation (
    • Dinosaurs (
    • Earth (
    • Inventions (
    • Physical Science (
    • Plants (
    • Scientists (
  • Social Studies (
    • Anthropology (
    • Economics (
    • Government (
    • Religion (
    • Holidays (
  • Space and Astronomy
    • Solar System (
    • Planets (
  • Sports (
  • Timelines (
  • Weather (
  • US States (


  • Home Page (
  • Contact Us (

  • Clip Art (
Personal tools