Edward Jenner

Edward Jenner was born on May 17, 1749, in Berkeley, a small market town in Gloucestershire in the west of England. He was the eighth of nine children of the Reverend Stephen Jenner, vicar of Berkeley, and his wife Sarah. Both parents died when Edward was five years old, and he was raised largely by his older siblings, particularly his brother Stephen, who had followed their father into the church ^[1].

As a schoolboy at Wotton-under-Edge, Jenner was inoculated against smallpox by the older method known as variolation, in which material from a smallpox pustule was deliberately introduced into a healthy person to provoke a mild case and lasting immunity. The procedure of that era involved weeks of preparation, including fasting, purging, and bloodletting, and the experience reportedly affected his health for some time afterward. It also gave him a direct, personal acquaintance with the disease that would define his career ^[2].

At thirteen he was apprenticed to Daniel Ludlow, a surgeon at Chipping Sodbury near Bristol. Tradition holds that during these years he heard a dairymaid claim she could never take smallpox because she had already had cowpox, a mild disease caught from cattle. Whether or not that exact conversation happened, the belief was common among Gloucestershire farming people, and Jenner carried the idea with him for decades before testing it ^[1].

In 1770 Jenner moved to London to complete his training under John Hunter, the Scottish surgeon and anatomist whose house doubled as a school of experimental science. Hunter took the young man as a resident pupil at St George's Hospital and became his lifelong mentor and correspondent. Hunter's advice to Jenner on one occasion, urging him to test a question by experiment rather than speculation, captured the working method Jenner would later apply to cowpox ^[3].

Jenner turned down opportunities in London, including an invitation connected with cataloguing specimens from Captain Cook's first voyage, and returned to Berkeley in 1773 to practise as a country doctor. He was no narrow provincial, though. He studied geology, ballooning, and bird behaviour, and his paper on the nesting habits of the cuckoo, which described how the newly hatched cuckoo chick ejects its foster siblings from the nest, earned him election as a Fellow of the Royal Society in 1789 ^[3].

Throughout the 1770s and 1780s Jenner kept notes on cowpox cases in his district. He observed that milkers who had contracted cowpox from infected udders resisted smallpox when later variolated, and he began to suspect that the folk belief rested on a real biological effect. He discussed the subject so persistently at meetings of a local medical society that colleagues reportedly threatened to expel him if he raised it again ^[2].

The decisive test came in May 1796. A young dairymaid named Sarah Nelmes consulted Jenner with cowpox sores on her hand, caught from a cow called Blossom. On May 14 Jenner took matter from one of her lesions and inserted it into scratches on the arm of James Phipps, the eight-year-old son of his gardener. The boy developed a slight fever and a small sore, then recovered fully. In July, Jenner variolated Phipps with live smallpox material. No disease followed, and repeated later challenges produced the same result ^[4].

Jenner submitted a paper to the Royal Society, which declined to publish it on the grounds that the evidence was too thin. He responded by gathering more cases, and in 1798, after a fresh outbreak of cowpox let him repeat the procedure on several more children, including his own eleven-month-old son Robert, he published his findings privately as An Inquiry into the Causes and Effects of the Variolae Vaccinae. The seventy-five page pamphlet described twenty-three cases and argued that cowpox inoculation gave protection against smallpox without the dangers of variolation ^[4].

He coined his terminology from the Latin vacca, meaning cow: the infectious material was variolae vaccinae, smallpox of the cow. The word vaccination for the procedure followed, and decades later Louis Pasteur proposed extending the term to all protective inoculations in Jenner's honour ^[5].

The Inquiry provoked both enthusiasm and hostility. Some physicians failed to reproduce the results, often because they used contaminated or spurious material, and variolators whose income was threatened attacked the method. Caricaturists, most famously James Gillray in 1802, mocked vaccination with images of patients sprouting cow heads from their bodies. Clergymen questioned the propriety of transferring an animal disease to human beings ^[5].

Careful practitioners soon confirmed Jenner's claims, and the practice spread with remarkable speed. Within a few years vaccination had reached most of Europe and crossed the Atlantic; Benjamin Waterhouse introduced it to the United States, and President Thomas Jefferson corresponded with Jenner about it. In 1803 the Spanish crown sent the Balmis expedition to carry the vaccine to its American and Asian territories, one of the first international public health campaigns in history ^[6].

Parliament recognised the discovery with grants of 10,000 pounds in 1802 and a further 20,000 pounds in 1807, substantial sums that acknowledged how much time and income Jenner had sacrificed answering correspondence and supplying vaccine free of charge. Napoleon, at war with Britain, nonetheless had his own army vaccinated and is said to have released English prisoners at Jenner's request, remarking that he could refuse nothing to such a man ^[6]. The Royal Jennerian Society was founded in London in 1803 to promote the practice, with Jenner as its president.

Jenner married Catherine Kingscote in March 1788, and the couple settled at The Chantry, a house beside the churchyard in Berkeley. They had three children: Edward, Catherine, and Robert. Family life brought repeated grief. His eldest son Edward died of tuberculosis in 1810 at the age of twenty-one, and Catherine, herself long troubled by the same disease, died in 1815. Jenner withdrew from public life after her death and rarely left Berkeley again ^[1].

In the garden of The Chantry, Jenner built a small thatched hut he called the Temple of Vaccinia, where he vaccinated the poor of the district without charge. The gesture was characteristic. Despite his fame he remained a working country doctor, riding out to patients across the Vale of Berkeley, and he consistently declined suggestions that he move to London and grow rich from a fashionable practice ^[7].

His curiosity never confined itself to medicine. He collected fossils, and in 1819 he unearthed bones of a plesiosaur near Berkeley. He wrote verse for friends, played the violin and flute, and continued the natural history observations, on bird migration among other subjects, that had first brought him scientific notice ^[3].

Honours accumulated through Jenner's final two decades. Oxford awarded him an honorary degree of Doctor of Medicine in 1813, and learned societies across Europe and America elected him to membership. In 1821 he was appointed physician extraordinary to King George IV, and he served his own community as a magistrate and as mayor of Berkeley ^[2].

He continued to defend and refine vaccination, publishing further papers on the sources of vaccine matter and on cases where protection appeared to fail. He recognised that spurious cowpox and careless technique explained many reported failures, though the question of how long immunity lasted, and whether revaccination might be needed, remained unsettled in his lifetime. He also returned to natural history, and his study of bird migration appeared after his death ^[3].

On January 25, 1823, Jenner was found unconscious at his home, having suffered a stroke. He died the following morning, January 26, 1823, at Berkeley, aged seventy-three. He was buried in the chancel of the parish church of St Mary, a few steps from the house where he had lived and worked, alongside his wife and parents ^[1].

Any list of Edward Jenner achievements begins with a number: smallpox had killed an estimated 400,000 Europeans a year in the eighteenth century, and it was the vaccine descended from his work that finally ended it. After a global campaign led by the World Health Organization, the last natural case occurred in Somalia in 1977, and in 1980 the WHO declared smallpox eradicated, the only human disease so far eliminated by deliberate action ^[8].

Jenner is often called the father of immunology. He did not understand viruses or antibodies, concepts that lay a century in the future, but he established by controlled trial that exposure to a mild related infection could protect against a deadly one, and he published his evidence for others to test. Pasteur's rabies and anthrax vaccines, and every vaccine since, extend the principle he demonstrated on James Phipps's arm in 1796 ^[5].

His memory is kept in stone and in institutions. Statues of Jenner stand in Gloucester Cathedral and in Kensington Gardens in London, the latter originally erected in Trafalgar Square in 1858. The Chantry at Berkeley is now Dr Jenner's House Museum, preserving the Temple of Vaccinia, and the Jenner Institute at the University of Oxford, which developed the Oxford-AstraZeneca COVID-19 vaccine, carries his name into current research ^[7]. Among Edward Jenner facts, perhaps the most striking is the estimate, often repeated by historians of medicine, that his work has saved more lives than that of any other single person.