The History of Smallpox

The Rise and Fall of a Disease

The history of the rise and fall of smallpox is a success story for "modern" medicine and public health. Even though the disease has been eradicated, the threat of its return has once again brought it to the forefront of public controversy.

The origin of smallpox is uncertain, but it is believed to have originated in Africa and then spread to India and China thousands of years ago. The first recorded smallpox epidemic was in 1350 BC during the Egyptian-Hittite war.

Smallpox reached Europe between the 5th and 7th centuries and was present in major European cities by the 18th century. Epidemics occurred in the North American colonies in the 17th and 18th centuries. At one time smallpox was a significant disease in every country throughout the world except Australia and a few isolated islands. Millions of people died in Europe and Mexico as a result of widespread smallpox epidemics.

The fall of smallpox began with the realization that survivors of the disease were immune for the rest of their lives. This led to the practice of variolation - a process of exposing a healthy person to infected material from a person with smallpox in the hopes of producing a mild disease that provided immunity from further infection. The first written account of variolation describes a Buddhist nun practicing around 1022 to 1063 AD. She would grind up scabs taken from a person infected with smallpox into a powder, and then blow it into the nostrils of a non-immune person.

By the 1700's, this method of variolation was common practice in China, India, and Turkey. In the late 1700's European physicians used this and other methods of variolation, but reported "devastating" results in some cases. Overall, 2% to 3% of people who were variolated died of smallpox, but this practice decreased the total number of smallpox fatalities by 10-fold.

The next step towards the eradication of smallpox occurred with the observation by English physician, Edward Jenner, that milkmaids who developed cowpox, a less serious disease, did not develop the deadly smallpox. In 1796, Jenner took the fluid from a cowpox pustule on a dairymaid's hand and inoculated an 8-year-old boy. Six weeks later, he exposed the boy to smallpox, and the boy did not develop any symptoms. Jenner coined the term "vaccine" from the word "vaca" which means "cow" in Latin. His work was initially criticized, but soon was rapidly accepted and adopted. By 1800 about 100,000 people had been vaccinated worldwide.

The "modern" vaccine that was licensed by the FDA was taken from a weak strain of virus called the New York City Board of Health strain. It was produced by Wyeth Laboratories and licensed under the name Dryvax. The last outbreak of smallpox in the United States occurred in Texas in 1949 with 8 cases and 1 death. Even though most of North America, Western Europe, Australia, and New Zealand were free of smallpox by this time, other countries such as Africa and India continued to suffer from epidemics.

In 1967 the World Health Organization (WHO) started a worldwide campaign to eradicate smallpox. This goal was accomplished in 10 years due in a large part to massive vaccination efforts. The last endemic case of smallpox occurred in Somalia in 1977. On May 8, 1980, the World Health Assembly declared the world free of smallpox.

The United States stopped vaccinating the general population in 1972, but continued to vaccinate military personnel. It was recommended that vaccination of military personnel stop in 1986, and vaccination was officially stopped in military recruits in 1990.

Information for this article was taken from
-Polgreen P, Helms C. Immunizations - Vaccines, biological warfare, and bioterrorism. Primary Care Clinics in Office Practice 01-Dec-2001; 28(4): 807-21, vii.
-Diven D. An overview of poxviruses. Journal of the American Academy of Dermatology 01-Jan-2001; 44(1): 1-16.
-Silvers M, Steptoe M. Immunizations - Historical overview of vaccines. Primary Care Clinics in Office Practice 01-Dec-2001; 28(4): 685-95, v.

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