Edward Jenner is famous for his invention of vaccination against smallpox. Before this vaccine was available, smallpox was a big problem around the globe, killing millions of people and especially infants and young children. However, thanks to Jenner's discovery, the work of other scientists and doctors, and improvements in standards of living, smallpox has been eradicated. The last natural case was reported on Somalia in October 1977 and in 1980 the World Health Assembly officially declared 'the world and its peoples' free from endemic smallpox.

Growing Up

Edward Jenner was born on 17 May, 1749¹ in Berkeley, a small market town in the Severn Valley in Gloucestershire. He was the eighth of nine children of the Reverend Stephen Jenner (1702 - 1754), Master of Arts from Oxford, rector of Rockhampton and vicar of Berkeley. His mother was a daughter of the Reverend Henry Head, a former vicar of Berkeley. His parents owned a considerable amount of land and the family had a comfortable life. However, in 1754 both parents died, leaving the five-year-old Edward to be looked after by an older sibling.

Edward loved the countryside where he lived and was very interested in nature. He learned to recognise and observe the life around him and could name all the plants and recognise the birds from their cries. He was also interested in fossils and would spend hours looking for them among the rocks. This interest in nature stayed with him his whole life.

Education

Edward started his school life in the nearby village of Wotton-under-Edge. He then went to a grammar school in Cirencester before studying under a clergyman back in Wotton-under-Edge. It was this clergyman who gave him an early interest in the classics. Fortunately, however, he did not follow this path and decided instead to study medicine, and in 1761 (at just 13 years of age) he became apprenticed to Abraham Ludlow, a surgeon of Sodbury, near Bristol.

It was while he was learning with Dr Ludlow that he first became aware of the problem of smallpox and its link with cowpox. It was common knowledge among the farming community that most people who caught cowpox would not get smallpox, and milkmaids would be relieved when they caught the relatively harmless cowpox instead.

Jenner finished his training with Dr Ludlow in 1770 at the age of 21 and moved to London for further education. At that time, studying medicine at university was both expensive and mostly theoretical, and so Jenner opted to go St George's Hospital. John Hunter (his teacher at St George's) taught him scientific methods as well as anatomy and physiology, and he learned not just to look and think but to experiment. Hunter also encouraged Jenner to study natural history and incorporated many of Jenner's observations in his own papers. By 1773, Jenner had finished his training and returned to Berkeley where he lived with his elder brother and built a very successful practice as a village surgeon.

The Problem Of Smallpox

Smallpox was a leading cause of death in the 18th Century². It affected all social classes, left many of the patients who recovered disfigured, and there was no effective treatment against it. The only way of fighting the disease was by intentionally infecting a healthy person with the matter taken from a patient sick with a mild attack of smallpox. This would hopefully give the person a mild case of smallpox so they would gain immunity from the disease. However, this was very dangerous, as the induced smallpox could be very disfiguring or even fatal and also could trigger an outbreak in the population.

At his practice in Berkeley, Jenner inoculated patients in this way. He noticed that patients who had had cowpox did not contract even a mild case of smallpox after the inoculation. Jenner was familiar with the folklore he learned whilst doing his apprenticeship, but now took it one step further and concluded that cowpox not only protected against smallpox, but could be transferred from one human being to another as a deliberate mechanism of protection. Jenner observed that there were many types of cowpox and experimented until he found the type that gave immunity against smallpox. He called this type 'true cowpox'. Unfortunately for Jenner, at that period of time there was not much smallpox around Berkeley and so it was some time before he could put his theory to the test.

In May 1796, Jenner got his chance. A farm in Jenner's district was struck with cowpox and a young maid there, Sarah Nelmes, had fresh scars of cowpox on her finger, giving pus Jenner could use. Jenner spoke to the parents of a local eight-year-old boy, James Phipps, with no known history of either cowpox or smallpox. He obtained consent from them to do a very risky experiment that by today's ethical standards would never have been allowed. He removed pus from Sarah and deposited it over scratches he had made on the Phipps' arms. Phipps developed cowpox symptoms a week later and shortly recovered, as expected with cowpox. Two months later Jenner performed the risky part of the experiment. He inoculated Phipps with pus from a smallpox patient and waited to see if he got the disease. Phipps did not develop smallpox, even after repeated inoculations. The experiment was successful.

After further experimentation in the following years, Jenner published, at his own expense, a small 75-page book based on 23 cases in which cowpox had conferred lasting immunity to smallpox. In his paper Jenner used the term 'virus', which during the Middle Ages was used to describe 'a slimy, poisonous, malodorous liquid', and due to the significance of Jenner's work the modern medical definition of a virus now agrees with Jenner's viewpoint. This paper also described an allergic hypersensitivity reaction of the body, a reaction now known as 'anaphylaxis'. The work was not immediately well received. He moved to London to continue experimenting. Here he found support from a few well-known doctors at St George's. After some time even the sceptics could not deny the evidence that the vaccine worked. By 1800 it was being used in Europe as well as the UK and started spreading worldwide.

The Later Years

In 1785 Jenner acquired a comfortable Georgian country house at Berkeley, called The Chantry, where he resided for the rest of his life. In 1788, aged 39 years, Jenner married Catherine Kongscote and had three children with her, and he stayed with her until her death in 1815. In 1792 Jenner obtained the medical doctorate from the University of St Andrews in Fife, Scotland. He became a physician, a more reputable and better paid job than his previous one as a surgeon, and from then until 1815 he practiced as a balneologist³ at the spa in Cheltenham. In 1813 the University of Oxford awarded him an honorary MD degree for his work. He carried on his interest in natural history throughout his life. On 25 January, 1823 he was found unconscious on the floor of his library. He had had a stroke and his right side was completely paralysed. He died early the next morning.

A museum dedicated to Jenner was opened in 1985 at Jenner's former residence, The Chantry. The website of this museum can be found at http://www.jennermuseum.com.