History of smallpox
The history of smallpox extends into pre-history; the disease likely emerged in human populations about 10,000 BC. The earliest credible evidence of smallpox is found in the Egyptian mummies of people who died some 3000 years ago. During the 18th century the disease killed an estimated 400,000 Europeans each year, including five reigning monarchs, and was responsible for a third of all blindness. Between 20 and 60% of all those infected—and over 80% of infected children—died from the disease.
During the 20th century, it is estimated that smallpox was responsible for 300–500 million deaths. In the early 1950s an estimated 50 million cases of smallpox occurred in the world each year. As recently as 1967, the World Health Organization estimated that 15 million people contracted the disease and that two million died in that year. After successful vaccination campaigns throughout the 19th and 20th centuries, the WHO certified the eradication of smallpox in December 1979. To this day, smallpox is the only human infectious disease to have been completely eradicated.
Eurasian epidemics 
There are no unequivocal records of smallpox in Europe before the 6th century CE, but it has been suggested that it was a major component of the Plague of Athens that occurred in 430 BCE, during the Peloponnesian Wars, and was described by Thucydides. A recent analysis of the description of clinical features provided by Galen during the Antonine Plague that swept through the Roman Empire and Italy in 165–180, indicate that it was probably caused by smallpox. Although some historians believe that many historical epidemics and pandemics were early outbreaks of smallpox, contemporary records are not detailed enough to make a definite diagnosis. In the 2nd century, returning soldiers brought the disease home with them to Syria and Italy, where it raged for fifteen years and greatly weakened the Roman empire, killing up to one-third of the population in some areas. Total deaths have been estimated at 5 million. A second major outbreak of disease in the Roman Empire, known as the Plague of Cyprian (251–266), was also either smallpox or measles.
Most of the details about the epidemics are lost, probably due to the scarcity of surviving written records from the Early Middle Ages. The first incontrovertible description of smallpox in Western Europe occurred in 581, when Bishop Gregory of Tours provided an eyewitness account describing the characteristic symptoms of smallpox. Waves of epidemics wiped out large rural populations. The establishment of the disease in Europe was of special importance, for this served as the endemic reservoir from which smallpox spread to other parts of the world, as an accompaniment of successive waves of European exploration and colonization.
Around 400 AD, an Indian medical book recorded a disease marked by pustules and boils, 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, Sitala, as the anthropomorphic personification of the disease. Smallpox was thus regarded as possession by Sitala. In Hinduism the goddess Sitala both causes and cures high fever, rashes, hot flashes and pustules. All of these are symptoms of smallpox.
The clearest description of smallpox from pre-modern times was given in the 9th century by the Persian physician, Muhammad ibn Zakariya ar-Razi, known in the West as "Rhazes", who was the first to differentiate smallpox from measles and chickenpox in his Kitab fi al-jadari wa-al-hasbah (The Book of Smallpox and Measles).
Smallpox was a leading cause of death in the 18th century. Every seventh child born in Russia died from smallpox. It killed an estimated 400,000 Europeans each year in the 18th century, including five reigning European monarchs. Most people became infected during their lifetimes, and about 30% of people infected with smallpox died from the disease, presenting a severe selection pressure on the resistant survivors.
In 1849 nearly 13% of all Calcutta deaths were due to smallpox. Between 1868 and 1907, there were approximately 4.7 million deaths from smallpox in India. Between 1926 and 1930, there were 979,738 cases of smallpox with a mortality of 42.3%.
African epidemics 
One of the earliest records of what may have been an encounter with smallpox in Africa is associated with the elephant war in 568 AD when after fighting a siege in Mecca, Ethiopian troops contracted the disease which they carried with them back to Africa. Arab ports in Coastal towns in Africa likely contributed to the importation of smallpox into Africa, as early as the 13th century, though no records exist until the 16th century. Upon invasion of these towns by tribes in the interior of Africa, a severe epidemic affected all African inhabitants while leaving the Portuguese spared. Densely populated areas of Africa connected to the Mediterranean, Nubia and Ethiopia by caravan route likely were affected by smallpox since the 11th century, though written records do not appear until the introduction of the slave trade in the 16th century.
The slave trade continued to spread smallpox to the entire continent, with raiders pushing farther inland along caravan routes in search of slaves. The effects of smallpox could be seen along caravan routes, and those who were not affected along the routes were still likely to become infected either waiting to board or on board ships.
Smallpox in Angola was likely introduced shortly after Portuguese settlement of the area in 1484. The 1864 epidemic killed 25,000 inhabitants, one third of the total population in that same area. In 1713, an outbreak occurred in South Africa after a ship from India docked at Cape Town, bringing infected laundry ashore. Many of the white population suffered, and whole clans of the Hottentot tribe were wiped out. A second outbreak occurred in 1755, again affecting both the white population and the Hottentots. The Hottentots spread the disease further among their tribes, and completely eradicating several tribes, all the way to the Kalahari desert. A third outbreak in 1767 similarly affected the Hottentots and Bantu tribes, but the whites settlers, having practiced variolation, were not affected nearly to the extent that they were in the first two outbreaks. Continued slaving operations brought smallpox to Cape Town again in 1840, taking the lives of 2500 people, and then to Uganda in the 1840s. It is estimated that up to eighty percent of the Griqua tribe was exterminated by smallpox in 1831, and whole tribes were being wiped out in Kenya up until 1899. Along the Zaire river river basin were areas where no one survived the epidemics, leaving the land devoid of human life. In Ethiopia and the Sudan, Six epidemics occurred in over the 19th century as follows: 1811–1813, 1838–1839, 1865–1866, 1878–1879, 1885–1887, and 1889–1890.
Epidemics in the Americas 
|1520–1527||Mexico, Central America, South America||Smallpox kills millions of native inhabitants of Mexico. Unintentionally introduced at Veracruz with the arrival of Panfilo de Narvaez on April 23, 1520 and was credited with the victory of Cortes over the Aztec empire at Tenochtitlan (present-day Mexico City) in 1521. Kills the Inca ruler, Huayna Capac, and 200,000 others and weakens the Incan Empire.|
|1561–1562||Chile||No precise numbers on deaths exist in contemporary records but it is estimated that natives lost 20 to 25 percent of their population. According to Alonso de Góngora Marmolejo so many Indian laborers died that the Spanish gold mines had to shut down.|
|1617–1619||North America northern east coast||Killed 90% of the Massachusetts Bay Indians|
|1674||Cherokee Tribe||Death count unknown. Population in 1674 about 50,000. After 1729, 1738, and 1753 smallpox epidemics their population was only 25,000 when they were forced to Oklahoma on the Trail Of Tears.|
|1702–1703||St. Lawrence Valley, NY|
|1770s||West Coast of North America||Kills out 30% of the West Coast Native Americans|
|1830s||Alaska||Reduced Dena'ina Athabaskan population in Cook Inlet region of southcentral Alaska by half. Smallpox also devastated Yup'ik Eskimo populations in western Alaska.|
|1865–1873||Philadelphia, PA, New York, Boston, MA and New Orleans, LA||Same period of time, in Washington D.C., Baltimore, MD, Memphis, TN, Cholera and a series of recurring epidemics of Typhus, Scarlet Fever and Yellow Fever|
|1877||Los Angeles, CA|
After first contacts with Europeans and Africans, some believe that the death of 90–95% of the native population of the New World was caused by Old World diseases. It is suspected that smallpox was the chief culprit and responsible for killing nearly all of the native inhabitants of the Americas. For more than 200 years, this disease affected all new world populations, mostly without intentional European transmission, from contact in the early 16th century to until possibly as late as the French and Indian Wars (1754–1767).
In 1519 Hernán Cortés landed on the shores of what is now Mexico and was then the Aztec empire. In 1520 another group of Spanish arrived in Mexico from Hispaniola, bringing with them the smallpox which had already been ravaging that island for two years. When Cortés heard about the other group, he went and defeated them. In this contact, one of Cortés's men contracted the disease. When Cortés returned to Tenochtitlan, he brought the disease with him.
Soon, the Aztecs rose up in rebellion against Cortés and his men. Outnumbered, the Spanish were forced to flee. In the fighting, the Spanish soldier carrying smallpox died. After the battle, the Aztecs contracted the virus from the invaders' bodies. Cortes would not return to the capital until August 1521. In the meantime smallpox devastated the Aztec population. It killed most of the Aztec army and 25% of the overall population. The Spanish Franciscan Motolinia 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 Cortés's return, he found the Aztec army’s chain of command in ruins. The soldiers who still lived were weak from the disease. Cortés then easily defeated the Aztecs and entered Tenochtitlán. The Spaniards said that they could not walk through the streets without stepping on the bodies of smallpox victims.
The effects of smallpox on Tahuantinsuyu (or the 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 Incan Emperor 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 emperor. 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. A handful of historians argue that a disease called Bartonellosis might have been responsible for some outbreaks of illness, but this opinion is in the scholarly minority. The effects of Bartonellosis were depicted in the ceramics of the Moche people of ancient Peru.
Even after the two largest empires of the Americas were defeated by the virus and disease, smallpox continued its march of death. In 1561, smallpox reached Chile by sea, when a ship carrying the new governor Francisco de Villagra landed at La Serena. Chile had previously been isolated by the Atacama Desert and Andes Mountains from Peru, but at the end of 1561 and in early 1562, it ravaged the Chilean native population. Chronicles and records of the time left no accurate data on mortality but more recent estimates are that the natives lost 20 to 25 percent of their population. The Spanish historian Marmolejo said that gold mines had to shut down when all their Indian labor died. Mapuche fighting Spain in Araucanía regarded the epidemic as a magical attempt by Francisco de Villagra to exterminate them because he could not defeat them in the Arauco War.
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 Mohawks in 1634, the Lake Ontario area in 1636, and the lands of the Iroquois by 1679. During the 1770s, smallpox killed at least 30% of the West Coast Native Americans. The smallpox epidemic of 1780–1782 brought devastation and drastic depopulation among the Plains Indians. This epidemic is a classic instance of European immunity and non-European vulnerability. It is probable that the Indians contracted the disease from the ‘Snake Indians’ on the Mississippi. From there it spread eastward and northward to the Saskatchewan River. According to David Thompson’s account, the first to hear of the disease were fur traders from the Hudson’s House on October 15, 1781. A week later reports were made to William Walker and William Tomison, who were in charge of the Hudson and Cumberland Hudson’s Bay Company posts. By February, the disease spread as far as the Basquia Tribe. Smallpox attacked whole tribes and left few survivors. E. E. Rich described the epidemic by saying that “Families lay unburied in their tents while the few survivors fled, to spread the disease.” After reading Tomison’s journals, Houston and Houston, have calculated that out of the Indians that traded at the Hudson and Cumberland houses, ninety-five percent died of smallpox. Paul Hackett adds to the mortality numbers suggesting that perhaps up to one half to three quarters of the Ojibway situated west of the Grand Portage died from the disease. The Cree also suffered a casualty rate of approximately seventy-five percent with similar effects found in the Lowland Cree. By 1785 the Sioux Indians of the great plains had also been affected. Not only did smallpox devastate the Indian population, it did so in an unforgiving way. William Walker described the epidemic stating that “the Indians [are] all Dying by this Distemper … lying Dead about the Barren Ground like a rotten sheep, their Tents left standing & the Wild beast Devouring them.”
A particularly virulent sequence of smallpox outbreaks 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 Thirteen Colonies.
In the late 1770s, during the American Revolutionary War, smallpox returned once more and killed an estimated 125,000 people. Peter Kalm in his Travels in North America, described how in that period, the dying Indian villages became overrun with wolves feasting on the corpses and weakened survivors.
In 1900 starting in New York City, smallpox reared its head once again and started a sociopolitical battle with lines drawn between the rich and poor, white and black. In populations of railroad and migrant workers who traveled from city to city the disease had reached a endemic low boil. This fact did not bother the government at the time, nor did it spur them to action. Despite the general acceptance of the germ theory of disease, pioneered by John Snow in 1849, smallpox was still thought to be mostly a malady that followed the less-distinct guidelines of a "filth" disease, and therefore would only affected the "lower classes".
In Canada, between 1702–1703, nearly a quarter of the population of Quebec city died due to a smallpox epidemic.
Australasian epidemics 
In 1789, near Sydney, smallpox devasted the Aboriginal population of coastal New South Wales (NSW). The extent of this outbreak is disputed, but some sources claim that it killed about 50% of all indigenous Australians.
Controversy has long surrounded a popular theory that smallpox was introduced to NSW in 1789 by British settlers. The hypothesis was tentatively put forward in 1914 by the Director of the Australian Quarantine Service, Dr. J.H.L. Cumpston. and most forcefully stated by the economic historian, Noel Butlin, in 1983. This theory was rebutted by Judy Campbell's full length book Invisible Invaders (2002). In particular, Campbell argued that scientific evidence concerning the viability of variolous matter (used for inoculation) does not support the possibility of the disease being brought to Australia on the long voyage from Europe. Some, however, such as Christopher Warren (2007); and Craig Mear (2008); continue to hold that smallpox emanated from the importation of variolous matter on the First Fleet. Warren argued that Campbell's approach was based on a false premise. After H. A. Willis (2010) reiterated Campbell's argument, Warren (2011) suggested that Willis had not taken into account research on how heat affects the smallpox virus, cited by the World Health Organization. Willis (2011) replied that his position was supported by a closer reading of Fenner’s WHO Report. and invited readers to consult the report online.
Campbell’s finding that the 1789 outbreak was introduced to Australia by Macassan mariners visiting Arnhem Land follows the opinion of C. C. Macknight, an authority on the interaction between indigenous Australians and the Macassans. Citing the scientific opinion of Frank Fenner (who wrote the forward to her book), and historical documents, Campbell (2002) argued that the 1789 outbreak was introduced to Australia by Macassans, from where it spread overland. More recently, Macknight (2011) has re-entered the debate by declaring: “The overwhelming probability must be that it [smallpox] was introduced, like the later epidemics, by trepangers[disambiguation needed] on the north coast and spread across the continent to arrive in Sydney quite independently of the new settlement there.”
Early in history, it was observed that those who had contracted smallpox once were never struck by the disease again. Thought to have been discovered by accident, it became known that those who contracted smallpox through a break in the skin in which smallpox matter was inserted received a less severe reaction than those who contracted it naturally. This realization led to the practice of purposely infecting people with matter from smallpox scabs in order to protect them later from a more severe reaction. This practice, known today as variolation, was first practiced in China in the 10th century. Methods of carrying out the procedure varied depending upon location. Variolation was the sole method of protection against smallpox other than quarantine until Jenner's discovery of the inoculating abilities of cowpox against the smallpox virus in 1798. Efforts to protect populations against smallpox by way of vaccination followed for centuries after Jenner's discovery. Smallpox has since been completely eradicated since 1979, because of the mass vaccination efforts of the World Health Organization.
The word variolation is synonymous with inoculation, insertion, en-grafting, or transplantation. The term is used to define insertion of smallpox matter, and distinguishes this procedure from vaccination, where cowpox matter was used to obtain a much milder reaction among patients.
The practice of variolation (also known as inoculation) first came out of the orient. First writings documenting variolation in China appear around 1500. Scabs from smallpox victims who had the disease in its mild form would be selected, and the powder was kept close to body temperature by means of keeping it close to the chest, killing the majority of the virus and resulting in a more mild case of smallpox. Scabs were generally used when a month old, but could be used quicker in hot weather (15–20 days), and slower in winter (50 days). The process was carried out by taking eight smallpox scabs and crushing them in a mortar with two grains of Uvularia grandiflora in a mortar. The powder was administered nasally through a silver tube that was curved at its point, through the right nostril for boys and the left nostril for girls. A week after the procedure, those variolated would start to produce symptoms of smallpox, and recovery was guaranteed. In India, where the European colonizers came across variolation in the 17th century, a large, sharp needle was dipped into the pus collected from mature smallpox sores. Several punctures with this needle were made either below the deltoid muscle or in the forehead, and then were covered with a paste made from boiled rice. Variolation spread further from India to other countries in south west Asia, and then to the Balkans.
Mary Wortley Montagu 
In 1713, Mary Wortley Montagu's brother died of smallpox; she too contracted the virus two years later at the age of twenty-six, leaving her badly scarred. When her husband was made ambassador to Turkey, she accompanied him to Constantinople. It was here that Montagu first came upon variolation. Two Greek women made it their business to engraft people with pox that left them un-scarred and unable to catch the pox again. In a letter, she wrote that she intended to have her own son undergo the process and would try to bring variolation into fashion in England. Her son underwent the procedure, which performed by Dr. Charles Maitland, and survived with no ill effects. When an epidemic broke out in London following her return, Mary Wortley Montagu wanted to protect her daughter from the virus by having her variolated as well. Maitland performed the procedure, which was a success. The story made it to the newspapers and was a topic for discussion in London salons. Princess Caroline of Wales wanted her children variolated as well but first wanted more validation of the operation. She had both an orphanage and several convicts variolated before she was convinced. When the operation, performed by the King's surgeon, Claude Amyand, and overseen by Maitland, was a success, variolation got the royal seal of approval and the practice became widespread.
When the practice of variolation set off local epidemics and caused death in two cases, public reaction was severe. Minister Edmund Massey, in 1772, called variolation dangerous and sinful, saying that people should handle the disease as the biblical figure Job did with his own tribulations, without interfering with God's test for mankind. Lady Mary still worked at promoting variolation but its practice waned until 1743.
Robert and Daniel Sutton further revived the practice of variolation in England by advertising their perfect variolation record, maintained by selecting patients who were healthy when variolated and were cared for during the procedure in the Sutton's own hygienic hospital. Other changes that the Suttons made to carrying out the variolation process include reducing and later abolishing the preparatory period before variolation was carried out, making more shallow incisions to distribute the smallpox matter, using smallpox matter collected on the fourth day of the disease, where the pus taken was still clear, and recommending that those inoculated get fresh air during recovery. The introduction of the shallower incision reduced both complications associated with the procedure and the severity of the reaction. The prescription of fresh air caused controversy about Sutton's method and how effective it was in reality when those inoculated could walk about and spread the disease to those that had never before experienced smallpox. It was the Suttons who introduced the idea of mass variolation of an area when an epidemic broke out as means of protection to the inhabitants in that location.
News of variolation spread to the royal families of Europe. Several royal families had themselves variolated by English physicians claiming to be specialists. Recipients include the family of Louis XV following his own death of smallpox, and Catherine the Great, whose husband had been horribly disfigured by the disease. Catherine the Great was variolated by Thomas Dimsdale, who followed Sutton's method of inoculation. In France, the practice was sanctioned until an epidemic was traced back to an inoculation. After this instance, variolation was banned within city limits. These conditions caused physicians to move just outside the cities and continue to practice variolation in the suburbs.
Edward Jenner 
Edward Jenner was variolated in 1756 at age eight in an inoculation barn in Wooton, England. At this time, in preparation for variolation children were bled repeatedly and were given very little to eat and only given a diet drink made to sweeten their blood. This greatly weakened the children before the actual procedure was given. Jenner's own inoculation was administered by a Mr. Holbrow, an apothecary. The procedure involved scratching the arm with the tip of a knife, placing several smallpox scabs in the cuts and then bandaging the arm. After receiving the procedure, the children stayed in the barn for several weeks to recover. First symptoms occurred after one week and usually cleared up three days later. On average, it took a month to fully recover from the encounter with smallpox combined with weakness from the preceding starvation.
At the age of thirteen, Jenner was sent to study medicine in Sodbury with Daniel Ludlow, a surgeon and apothecary, from 1762–1770 who had a strong sense of cleanliness which Jenner learned from him. During his apprenticeship, Jenner heard that upon contracting cowpox, the recipient became immune to smallpox for the remainder of their life. However, this theory was dismissed because of several cases proving that the opposite was true. After learning all he could from Ludlow, Jenner apprenticed with John Hunter in London from 1770–1773. Hunter was a correspondent of Ludlow’s, and it is likely that Ludlow recommended Jenner to apprentice with Hunter. Hunter believed in deviating from the accepted treatment and trying new methods if the traditional methods failed. This was considered unconventional medicine for the time period and had a pivotal role in Jenner's development as a scientist. After two years of apprenticeship, Jenner moved back to his hometown of Berkeley, where he quickly gained the respect of both his patients and other medical professionals for his work as a physician. It was during this time that Jenner revisited the connection between cowpox and smallpox. He began investigating dairy farms in the Gloucestershire area looking for cowpox. This research was slow going as Jenner often had to wait months or even years before cases of cowpox would again return to the Gloucestershire area. During his study, he found that cowpox was actually several diseases that were similar in nature but were distinguishable through slight differences, and that not all versions had the capacity to make one immune from smallpox upon contraction. Through his study, he incorrectly deduced that grease, smallpox and cowpox were all the same disease, simply manifesting themselves differently in different animals, eventually setting back his research and making it difficult to publish his findings. Though Jenner had seen cases of people becoming immune to smallpox after having cowpox, too many exceptions of people still contracting smallpox after having had cowpox were arising. Jenner was missing crucial information which he later discovered in 1796. Jenner hypothesized that in order to become immune to smallpox using cowpox, the matter from the cowpox pustules must be administered at maximum potency; else it was too weak to be effective in creating immunity to smallpox. He deduced that cowpox was most likely to transfer immunity from smallpox if administered at the eighth day of the disease. On May 14, 1796, he performed an experiment in which he took pus from a sore of a cowpox infected milkmaid named Sarah Nelmes and applied it to a few small scratches on the arm of an eight-year-old boy who had never before contracted either smallpox or cowpox, named James Phipps. Phipps recovered as expected. Two months later, Jenner repeated the procedure using matter from smallpox, observing no effect. Phipps became the first person to become immune to smallpox without ever actually having the disease. He was variolated about many more times over the course of his life to prove his immunity. When the next cowpox epidemic broke out in 1798, Jenner conducted a series of inoculations using cowpox, all of them successful except on his own son Robert. Because his findings were revolutionary and lacked in evidence, the Royal Society (of whom Jenner was a member) refused to publish his findings. Jenner then rode to London and had his book published by Sampson Low’s firm in June 1798 The book was an instant bestseller among the elite in London salons, in the medical establishment and among the ladies and gentlemen of the enlightenment. Knowledge of the ability of cowpox to provide immunity from smallpox was present in England before Jenner's discovery. In 1774, a cattle dealer named Benjamin Jesty successfully inoculated his wife and three sons using cowpox. This was before Jenner discovered the immunization capabilities of cowpox. However, Jesty simply performed the procedure; he did not take the discovery any further by inoculating his family with smallpox matter to see if there would be a reaction or perform any other trials. Jenner was the first to prove the effectiveness of vaccination with cowpox using experimentation.
United States of America 
Benjamin Franklin, who had lost his own son to smallpox in 1736, made the suggestion to create a pamphlet to distribute to families explaining how to inoculate their children themselves, so as to eliminate cost as the factor in the decision to choose to inoculate children. William Heberden, a friend of Franklin's and an English physician, followed through with Franklin's idea, printing 2000 pamphlets in 1759 which were distributed by Franklin in America. An American physician, John Kirkpatrick, upon his visit to London in 1743, told of an instance where variolation stopped an epidemic in Charleston, South Carolina, in 1738, where 800 people were inoculated and only eight deaths occurred. His account of the success of variolation in Charleston helped to play a role in the revival of its practice in London. Kirkpatrick also advocated inoculating patients with matter from the sores of another inoculated person, instead of using matter from the sore of a smallpox victim, a procedure that Maitland had been using since 1722.
- Barquet N, Domingo P (1997). "Smallpox: the triumph over the most terrible of the ministers of death". Ann. Intern. Med. 127 (8 Pt 1): 635–42. doi:10.1059/0003-4819-127-8_Part_1-199710150-00010. PMID 9341063.
- Fenner, F.; Henderson, D.A.; Arita, I.; Jezek, Z.; & Ladnyi, I.D. (1988). Smallpox and Its Eradication (History of International Public Health, No. 6) (PDF). Geneva: World Health Organization. ISBN 92-4-156110-6.
- Behbehani AM (1983). "The smallpox story: life and death of an old disease". Microbiol Rev 47 (4): 455–509. PMC 281588. PMID 6319980.
- Riedel S (2005). "Edward Jenner and the history of smallpox and vaccination". Proc (Bayl Univ Med Cent) 18 (1): 21–5. PMC 1200696. PMID 16200144.
- Koplow, David A. (2003). Smallpox: the fight to eradicate a global scourge. Berkeley: University of California Press. ISBN 0-520-24220-3.
- "UC Davis Magazine, Summer 2006: Epidemics on the Horizon". Retrieved 2008-01-03.
- How Poxviruses Such As Smallpox Evade The Immune System, ScienceDaily, February 1, 2008
- "Smallpox". WHO Factsheet. Retrieved 2007-09-22.
- De Cock KM (2001). "(Book Review) The Eradication of Smallpox: Edward Jenner and The First and Only Eradication of a Human Infectious Disease". Nature Medicine 7 (1): 15–6. doi:10.1038/83283.
- Littman, R. J.; Littman, M. L. (1973). "Galen and the Antonine Plague". The American Journal of Philology 94 (3): 243–255. doi:10.2307/293979. JSTOR 293979. PMID 11616517.
- Hopkins DR (2002). The Greatest Killer: Smallpox in history. University of Chicago Press. ISBN 0-226-35168-8. Originally published as Princes and Peasants: Smallpox in History (1983), ISBN 0-226-35177-7
- Plague in the Ancient World. Loyno.edu. Retrieved on 2011-12-06.
- Past pandemics that ravaged Europe, BBC News, November 7, 2005
- Heather Whipps, "How Smallpox Changed the World', LiveScience, June 23, 2008
- Nicholas R (1981). "The goddess Sitala and epidemic smallpox in Bengal, India". J Asian Stud 41 (1): 21–45. doi:10.2307/2055600. JSTOR 2055600. PMID 11614704.
- "Sitala and Smallpox". The thermal qualities of substance: Hot and Cold in South Asia. Retrieved 2006-09-23.
- Vassar: Points out that variolation was regarded as a means of invoking the goddess whereas vaccination was opposition to her. Gives duration of belief until fifty years ago. Reli350.vassar.edu. Retrieved on 2011-12-06.
- Otri AM, Singh AD, Dua HS (2008). "Cover illustration. Abu Bakr Razi". Br J Ophthalmol 92 (10): 1324. PMID 18815419.
- Smallpox and Vaccinia. Ncbi.nlm.nih.gov. Retrieved on 2011-12-06.
- Smallpox In Europe Selected For Genetic Mutation That Confers Resistance To HIV Infection. ScienceDaily. November 20, 2003
- Macintyre, Donald Meeting the First Inhabitants, TIME Asia. 21 August 2000
- Texas Department of State Health Services, History of Smallpox. Dshs.state.tx.us. Retrieved on 2011-12-06.
- The War Against Smallpox. Strategypage.com (2007-09-25). Retrieved on 2011-12-06.
- Rogers, L (1945). "Smallpox and Vaccination in British India During the Last Seventy Years". Proc R Soc Med. 38 (3): 135–40. PMC 2181657. PMID 19993010.
- Robin ED, McCauley RF (Jan–Mar 1997). "Smallpox – some unknown heroes in smallpox eradication". Indian Journal of Medical Ethics 5 (1).
- Fenner, Frank, Donald A. Henderson, Isao Arita, Zdenek Jezek, and Ivan Danilovich Ladnyi. Smallpox and its Eradication. Geneva: World Health Organization, 1988. WHO Library Database.
- Worldwide Epidemics 1999 Genealogy Inc
- The Demon in the Freezer. Randomhouse.com. Retrieved on 2011-12-06.
- Alonso de Góngora Marmolejo Historia de Chile desde su descubrimiento hasta el año 1575. Cervantesvirtual.com. Retrieved on 2011-12-06.
- Boraas AS (1991). Peter Kalifornsky: A Biography. In: A Dena’ina Legacy — K’tl’egh’i Sukdu: The Collected Writings of Peter Kalifornsky (Kari J, Boraas AS, eds). Fairbanks, AK: Alaska Native Language Center, University of Alaska Fairbanks. p. 475.
- The Story Of... Smallpox. Pbs.org. Retrieved on 2011-12-06.
- Henderson DA; Inglesby TV; Bartlett JG; Ascher, MS; Eitzen, E; Jahrling, PB; Hauer, J; Layton, M et al. (1999). "Smallpox as a biological weapon: medical and public health management. Working Group on Civilian Biodefense". JAMA 281 (22): 2127–37. doi:10.1001/jama.281.22.2127. PMID 10367824.
- Worldviews: Contact and Change (Alberta grade 8 social studies textbook), page 233.
- Quoted in Tzvetan Todorov, The Conquest of America: The Question of the Other (1999:136).
- – The War Against Smallpox. Strategypage.com (2007-09-25). Retrieved on 2011-12-06.
- Silent Killers of the New World. millersville.edu
- Cook, Noble David (2004). "Smallpox or Bartonellosis?": Comment on "Epidemics and Demographic Disaster in Colonial Latin America: A Reassessment" (PDF).
- Berrin, Katherine & Larco Museum. The Spirit of Ancient Peru:Treasures from the Museo Arqueológico Rafael Larco Herrera. New York: Thames and Hudson, 1997.
- Diego Barros Arana, Historia general de Chile, Tomo Segundo, pg. 51 note 87, pg. 231–232.
- Dutch Children's Disease Kills Thousands of Mohawks. Paulkeeslerbooks.com. Retrieved on 2011-12-06.
- Smallpox, The Canadian Encyclopedia
- Lange, Greg. (2003-01-23) Smallpox epidemic ravages Native Americans on the northwest coast of North America in the 1770s. Historyink.com. Retrieved on 2011-12-06.
- Houston CS, Houston S (2000). "The first smallpox epidemic on the Canadian Plains: In the fur-traders' words". Can J Infect Dis 11 (2): 112–5. PMC 2094753. PMID 18159275.
- Rich, E. E. and Johnson, A. M. (1952). Cumberland House Journals and Inland Journals 1775–82. London: The Hudson’s Bay Record Society.
- Rich EE (1967). The Fur Trade and the Northwest to 1875 (11th ed.). McClelland and Stewart Limited.
- Paul Hackett (2002). A Very Remarkable Sickness. University of Manitoba Press. ISBN 0-88755-659-0.
- Fenn EA (2001). Pox Americana: The Great Smallpox Epidemic of 1775–82 (1st ed.). Hill and Wang. ISBN 0-8090-7820-1.
- "Groundhog day at the wolf wars". Retrieved 2007-06-18.
- Lewis Cass and the Politics of Disease: The Indian Vaccination Act of 1832. Muse.jhu.edu. Retrieved on 2011-12-06.(registration required)
- Willrich, Micheal (2011). Pox: An American History. 1st ed. London, England: The Penguin Press p. 15-30
- "Smallpox Through History". Archived from the original on 2009-10-31.
- Cumpston, JHL "The History of Small-Pox in Australia 1788–1908", Government Printer (1914) Melb.
- Butlin, Noel | title=Our Original Aggression | publication-date=1983 | pp 19–24, 138–39
- Campbell, Judy; 2002, Invisible Invaders: Smallpox and Other Diseases in Aboriginal Australia 1780–1880, Carlton, Melbourne University Press, pp60–2, 80–1, 194–6, 201, 216–7
- Warren C. "Could First Fleet smallpox infect Aborigines? – A note". Aboriginal History 31: 152–164.
- Mear C. "The origin of the smallpox in Sydney in 1789". Journal of Royal Australian Historical Society 94 (1): 1–22.
- Willis, H. A (2010-09), "Poxy history [Smallpox and Aboriginal history.]", Quadrant (Sydney) 54 (9): 70–73, ISSN 0033-5002
- Warren, C. (2011), "The 1789 Smallpox", Quadrant (Sydney) 55 (4): 4, ISSN 0033-5002
- Willis, H.A. (2011), "Bringing Smallpox with the First Fleet", Quadrant (Sydney) 55 (7–8): 2, ISSN 0033-5002
- Macknight, C. C. "Macassans and the Aboriginal past" in Archaeologia Oceania | publication-date=1986 | volume=21 | pages=69–75
- Macknight, Campbell "The view from Marege’: Australian knowledge of Makassar and the impact of the trepang industry across two centuries " in Aboriginal History | publication-date=2011 | volume=35 | pages=121–143.
- New Zealand Historical Perspective. canr.msu.edu
- How did Easter Island's ancient statues lead to the destruction of an entire ecosystem?, The Independent
- U.S. National Library of Medicine. “Variolation.” Accessed October 29, 2012. www.nlm.nih.gov/exhibition/smallpox/sp_variolation.html
- Glynn, Ian and Jennifer Glynn. The Life and Death of Smallpox. New York: Cambridge University Press, 2004.
- Hopkins, Donald R. The Greatest Killer: Smallpox in History. Chicago: The University of Chicago Press, 2002.
- Case, Christine L, and Chung, King Thom. “Montagu and Jenner: The Campaign Against Smallpox." SIM News 47, no. 2 (1997): 58–60.
- Shurkin, Joel N. The Invisible Fire: The Story of Mankind's Triumph Over the Ancient Scourge of Smallpox. Toronto: Longman Canada, 1979.
- Halsal, Paul. ”Modern History Sourcebook: Lady Mary Wortley Montagu (1689–1762): Smallpox Vaccination in Turkey.” Fordham University. Accessed October 29, 2012. www.fordham.edu/halsall/mod/montagu-smallpox.asp
- MacNalty, Arthur S. “The Prevention of Smallpox: From Edward Jenner to Monckton Copeman.” Medical History 12, no. 1 (1968): 1–18.
- Bailey, Ian. “Edward Jenner (1749–1823): Naturalist, Scientist, Country Doctor, Benefactor to Mankind.” Journal of Medical Biography 4 no.2 (1996): 63–70.
- The UCLA Louise M. Darling Biomedical Library History and Special Collections Division. “Smallpox: an online exhibit.” Accessed October 29, 2012. Unitproj.library.ucla.edu/biomed/his/smallpox/jenner.html
- Wells, Lloyd Allan. "Why Not Try the Experiment?" The Scientific Education of Edward Jenner. Proceedings of the American Philosophical Society 41, no. 1 (1999): 108–110.
- Meynell, Elinor. "French Reactions to Jenner's Discovery of Smallpox Vaccination: The Primary Sources." Social History of Medicine 8 no.2 (1995): 287.
- McCandless, Peter. Slavery, Disease, and Suffering in the Southern Lowcountry. New York: Cambridge University Press, 2011
Further reading 
- Otto, Simon; Cappel, Constance (2007). The smallpox genocide of the Odawa tribe at L'Arbre Croche, 1763: the history of a Native American people. Lewiston, NY: Edwin Mellen Press. ISBN 0-7734-5220-6.
- "Hugh Walker and North Carolina's 'Smallpox Currency' of 1779", R. Neil Fulghum. The Colonial Newsletter, a research journal of the American Numismatic Society, New York. December 2005, pp. 2895–2934.
- Rich, E. E. and Johnson, A. M. (1952). Cumberland House Journals and Inland Journals 1775–82. London: The Hudson’s Bay Record Society.
- Sheldon Watts (1997). Epidemics and History:Disease, Power and Imperialism. New Haven: Yale University Press. ISBN 0-300-07015-2.