A History of Smallpox

Smallpox long reigned as the king of dreaded contagious diseases. It killed more people than any other virus in recorded history — about 500 million people in the 20th century alone. For about 20 years it seemed to have vanished, no longer haunting the dreams of most people. Many had never even heard of it. However, terrorists’ suicidal viciousness and new biological attacks have brought the threat of smallpox back to the future.

The first record of smallpox was a physical one: it was found in ancient Egyptian mummies. The first written descriptions are from early China where it was described as a disease from the west. The disease also spread as part of the great Islamic expansion across North Africa and into Spain. The ill-fated travel of the Crusades then brought it to the rest of Europe where for many generations it caused about 10% of all deaths every year.

European explorers then brought it to the American colonies, where epidemics were devastating to colonists – but especially to Native Americans. Smallpox-contaminated blankets may have been given to natives as intentional acts of biological warfare. Later, George Washington believed that British troops intentionally infected colonial forces with smallpox.

Eventually, almost everyone on earth got it. This airborne disease was so contagious that it became a standard feature of life on our planet. Most people recovered, but the overall mortality rate when infected was 1 to 30% — and even higher during some epidemics.

People with the illness got sick suddenly, with a high fever, headache, and marked fatigue. Nausea, vomiting, abdominal pain, back pain, and muscle pains were also common. A few days later, pox appeared – mostly on the face and legs.

Efforts at developing immunity to smallpox first began in China. A Buddhist nun living a millennium ago noticed that some people had milder cases of smallpox than others. She took powdered scabs from people who had mild cases and put them in healthy people’s noses to prevent serious infection. This process is called “variolation” after variola, the name of the smallpox virus. Variolation spread over the next 750 years. On balance, it was a beneficial practice, even though it caused the death of 2-3% of those variolated. I suspect that those who died from variolation would probably have died from smallpox anyway.

Variolation had come to England but had been outlawed because of the deaths it caused, when Edward Jenner made his momentous observations. Jenner noticed that milkmaids had unusually beautiful complexions. Over the course of a decade, he wondered if they were safe from smallpox because they had caught a much milder illness, cowpox, from their handling of the cows. On May 14, 1796, Jenner took material from cowpox on the hand of milkmaid Sarah Nelm and inoculated it into the arm of young James Phipps. Jenner then deliberately exposed Phipps to smallpox – and Phipps didn’t get it! With the solid success of using cowpox (the virus is called vaccinia), “vaccination” was born.*

The success was so dramatic that 10 years later President Thomas Jefferson predicted that one day people would only know about the dread of smallpox from reading history books. And there was a time that it looked as if Mr. Jefferson had been proven right. Join us for the next several days for DrGreene’s discussion of smallpox, anthrax, and his surprising conclusions for children’s health.

*Vaccination did not begin with Jenner, though he did both popularize it and coin the term. Decades earlier a cattle rancher named Benjamin Jesty used cowpox to protect his family from smallpox.