Used to rapid advances in medicine, the populace fails to appreciate the historical origins of vaccines and the challenges their creation represents. I used to enjoy lecturing on the history of germ theory and the discovery of vaccines, and central to such a discussion was smallpox.             

For many centuries, smallpox (a member of the orthopoxvirus family) was the scourge of mankind and affected all segments of society. 400,000 people died annually in 18th century Europe, and one-third of survivors went blind. Known as the “speckled monster” because of the small sacs that covered the skin, symptoms appeared suddenly and its progression was devastating. The fatality rate ranged from 20-60% and left survivors with horribly disfiguring scars. The fatality rate in infants was chilling (80% in London, 98% in Berlin). The word “variolae” was commonly used for smallpox and meant “mark on the skin.” The most successful means of combating smallpox before vaccination was a process called “variolation,” where a ripe pustule from a patient suffering from smallpox was lanced, and the liquid contents were subcutaneously introduced into the arms or legs of a non-infected individual. This practice was likely common in Africa, India and China long before the 18th century, at which time it was introduced in Europe, where it quickly became popular among physicians. After all, the 2-3% fatality rate from the procedure was at least 10 times lower than that associated with naturally occurring smallpox, although the procedure of variolation could also transmit other serious diseases.

[An interesting side note: variolation eventually spread to the American colonies. In 1766, American troops under George Washington were unable to capture Quebec from the British, because a smallpox epidemic had decimated his troops while the British troops had all been variolated. From then on, all American troops were variolated.]

Edward Jenner (1749-1823) was an English physician, who pioneered the concept of vaccines and is given credit for developing the smallpox vaccine. In his day, girls were hired as milkmaids to do the milking of dairy cows, and they would often catch cowpox (virus from the orthopoxvirus family), a mild viral skin infection, from diseased cows. But word had circulated that these girls did not catch smallpox.

Hearing this, Jenner developed the theory that cowpox could protect against smallpox. In 1796, he found a dairy maid named Sarah Nelms with fresh cowpox lesions (see drawing of her hand), removed some lesion fluid and inoculated an 8-year-old boy (James Phipps) with it. The boy developed a slight fever but nothing more. Nine days later, he inoculated Phipps with material from a fresh smallpox lesion and the boy failed to develop smallpox. He published a paper about the procedure and coined the term “vaccination” (‘vaccinia” is Latin for cowpox). Vaccination gradually replaced variolation. Strictly speaking, Jenner didn’t invent vaccination, but was the first person to give it scientific status and pursue its scientific investigation.

How things have changed. The smallpox vaccine was decades in the making, while the COVID vaccine took less than a year.

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