Origin of Smallpox

The origin of smallpox is unknown. Smallpox is thought to date back to the Egyptian Empire around the 3rd century BCE (Before Common Era), based on a smallpox-like rash found on three mummies. The earliest written description of a disease that clearly resembles smallpox appeared in China in the 4th century CE (Common Era). Early written descriptions also appeared in India in the 7th century and in Asia Minor in the 10th century.

Spread of Smallpox

The global spread of smallpox can be traced to the growth and spread of civilizations, exploration, and expanding trade routes over the centuries.

Historical Highlights:

6 th Century – Increased trade with China and Korea introduces smallpox into Japan.

Century – Increased trade with China and Korea introduces smallpox into Japan. 7 th Century – Arab expansion spreads smallpox into northern Africa, Spain, and Portugal.

Century – Arab expansion spreads smallpox into northern Africa, Spain, and Portugal. 11 th Century – Crusades further spread smallpox in Europe.

Century – Crusades further spread smallpox in Europe. 15 th Century – Portuguese occupation introduces smallpox into part of western Africa.

Century – Portuguese occupation introduces smallpox into part of western Africa. 16 th Century – European colonization and the African slave trade import smallpox into the Caribbean and Central and South America.

Century – European colonization and the African slave trade import smallpox into the Caribbean and Central and South America. 17 th Century – European colonization imports smallpox into North America.

Century – European colonization imports smallpox into North America. 18th Century – Exploration by Great Britain introduces smallpox into Australia.

Early Control Efforts

Smallpox was a devastating disease. On average, 3 out of every 10 people who got it died. Those who survived were usually left with scars, which were sometimes severe.

One of the first methods for controlling the spread of smallpox was the use of variolation. Named after the virus that causes smallpox (variola virus), variolation is the process by which material from smallpox sores (pustules) was given to people who had never had smallpox. This was done either by scratching the material into the arm or inhaling it through the nose. With both types of variolation, people usually went on to develop 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 an English doctor named Edward Jenner observed that milkmaids who had gotten cowpox did not show any symptoms of smallpox after variolation. The first experiment to test this theory involved milkmaid Sarah Nelmes and James Phipps, the 9 year-old son of Jenner’s gardener. Dr. Jenner took material from a cowpox sore on Nelmes’ hand and inoculated it into Phipps’ arm. Months later, Jenner exposed Phipps a number of 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 which 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 precise time remains unclear), the virus used to make the smallpox vaccine changed from cowpox to vaccinia virus.