This month marks 266 years since the birth of one of the most celebrated names in medical discovery. Edward Jenner, credited with the discovery of the smallpox vaccination, was born on 17 May 1749 (6 May by the Julian calendar, still in use in England by a quirk of anti-papal authoritarianism until 1752) in the village of Berkeley in Gloucestershire, England. He went to school in Wotton-under Edge and Cirencester, and between the ages of 13 and 21, studied surgery as an apprentice in Chipping Sodbury under the surgeon apothecary Daniel Ludlow, and later the country surgeon, George Hardwicke. He then took a position at St George’s Hospital in London under the wing of the well-known ‘scientific surgeon’, John Hunter. In 1772 Jenner returned home to Berkeley where he became practitioner and surgeon to the local community.
He was only 23 years of age, but had amassed nine years of knowledge and experience in dissection and investigation, an extraordinary erudition for one so young. Jenner’s interest in the smallpox disease may have been sparked during his earlier apprenticeship with Ludlow and Hardwicke where it is said (not everyone agrees) that he came across the dairy maid folklore ‘If I am exposed to and succumb to cowpox I will never get smallpox’. A well-known 17th century nursery rhyme, combined with some poetical exegesis, supports perhaps this folklore assertion “Where are you going to my pretty maid? I’m going a milking sir, she said… What is your fortune my pretty maid? My face is my fortune sir, she said”. (Weiss, R.A. & Esparza, J. 1755)
Smallpox and its treatment
During the 18th century, smallpox claimed around 400,000 lives per year in Europe. Of the survivors a third became blind. Although the method of variolation (Lat. varius = spotted or stained), in which fluid from a live smallpox sore was injected into individuals subcutaneously, had been known for some hundreds of years its adoption in Europe only began after a series of procedures had been carried out initially on members of the English aristocracy and then in a more controlled set of trials on Newgate prisoners and later orphaned children, with some success. By 1757 Jenner, now eight years of age, became a beneficiary, along with thousands of other English schoolboys of the vastly superior ‘Suttonian’ method of smallpox ‘inoculation’, developed by a Suffolk surgeon Robert Sutton, and later improved by his son Daniel. In this procedure a shallow stab with a lancet dipped in smallpox matter was made, penetrating only about a millimeter or so into the skin. This reduced the severity of post-inoculation symptoms but conferred immunity as effectively as earlier procedures and, despite clear cut differences in the morbidity statistics on natural exposure to smallpox (anything from 1-15% of those infected) and the Suttons’ inoculation exposure (perhaps lower than one in a thousand), the widely practiced Sutton procedures were not published until 1796.
Vaccination or variolation?
Jenner’s analytical approach to the relationship between exposure to cowpox and the subsequent immunity to smallpox, is reflected in his report of 23 case studies involving individuals or groups of individuals 1. who had been exposed naturally to cowpox and then smallpox, 2. who had been naturally exposed to cowpox and were then variolated, and 3. those who had experienced neither infection and were then inoculated with cowpox followed by smallpox. The first of the case studies appear to have occurred in 1743 but it was only the last seven of these occurring after 1790 that Jenner became personally aware of or involved with. The most famous of these was the case of Sarah Nelms, a milkmaid on a farm near to Berkeley. Reported as case XVI Jenner observes:
“SARAH NELMS, a dairymaid at a Farmer’s near this place, was infected with the Cow Pox from her master’s cows in May, 1796. She received the infection on a part of the hand …. A large pustulous sore and the usual symptoms accompanying the disease were produced in consequence…”
Jenner was convinced this was a genuine case of cowpox with a clean presentation. Here was the opportunity to test the hypothesis in a rigorous experiment. Jenner identified a young village boy, James Phipps, who had not yet been variolated, and injected the secretions from Sarah Nelms’s sores under Phipps’s skin as “two superficial incisions, barely penetrating the cutis, each about half an inch long…” This was in May 1796 and was the first example of a human-to-human vaccination. Two months later, Phipps was variolated by the same procedure and “… as I ventured to predict, produced no effect. I shall now pursue my experiments with redoubled ardour”. Jenner’s attempt to get his results published by the Royal Society of London failed for ‘lack of sufficient experimental evidence’. His conviction that this was an enormously important medical advance led him to finance the publication himself. This was not enough however to convince the entire medical community. Skepticism abounded until several renowned London physicians supported Jenner’s procedure.
This is part one of a two-part series on Edward Jenner and the discovery of the smallpox vaccine. Check back next week for part two.
Feature image credit: Edward Jenner vaccinating his young child. Coloured engraving by C. Manigaud after E Hamman, Wellcome Library. CC BY 4.0 via Wikimedia Commons.