The initial symptoms of the disease included fever and vomiting.[5] This was followed by formation of ulcers in the mouth and a skin rash.[5] Over a number of days, the skin rash turned into the characteristic fluid-filled blisters with a dent in the center.[5] The bumps then scabbed over and fell off, leaving scars.[5] The disease was transmitted from one person to another primarily through prolonged face-to-face contact with an infected person or (rarely) via contaminated objects.[6][13][14] Prevention was achieved mainly through the smallpox vaccine.[9] Once the disease had developed, certain antiviral medications could potentially have helped, but such medications did not become available until after the disease was eradicated.[9] The risk of death was about 30%, with higher rates among babies.[6][15] Often, those who survived had extensive scarring of their skin, and some were left blind.[6]
The earliest evidence of the disease dates to around 1500 BC in Egyptian mummies.[16][17] The disease historically occurred in outbreaks.[10] In 18th-century Europe, it is estimated that 400,000 people died from the disease per year, and that one-third of all cases of blindness were due to smallpox.[10][18] Smallpox is estimated to have killed up to 300 million people in the 20th century[19][20] and around 500 million people in the last 100 years of its existence.[21] Earlier deaths included six European monarchs, including Louis XV of France in 1774.[10][18] As recently as 1967, 15 million cases occurred a year.[10]
Inoculation for smallpox appears to have started in China around the 1500s.[22][23] Europe adopted this practice from Asia in the first half of the 18th century.[24] In 1796, Edward Jenner introduced the modern smallpox vaccine.[25][26] In 1967, the WHO intensified efforts to eliminate the disease.[10] Smallpox is one of two infectious diseases to have been eradicated, the other being rinderpest (a disease of even-toed ungulates) in 2011.[27][28] The term "smallpox" was first used in England in the 16th century to distinguish the disease from syphilis, which was then known as the "great pox".[29][30] Other historical names for the disease include pox, speckled monster, and red plague.[3][4][30]
^Koprowski H, Oldstone MB (1996). Microbe hunters, then and now. Medi-Ed Press. p. 23. ISBN978-0-936741-11-6.
^Henderson DA (December 2011). "The eradication of smallpox – an overview of the past, present, and future". Vaccine. 29 (Suppl 4): D7–9. doi:10.1016/j.vaccine.2011.06.080. PMID22188929.