… or cowpox and cuckoos, which may be more euphonious but is chronologically the wrong way round. It is apparently the case that Edward Jenner (1749–1823), more famous as the discoverer of vaccination against smallpox, was the first person to observe (or at any rate to observe and report on) the way in which the cuckoo deals with the real offspring of the birds on whom she is imposing her own egg.
Some thought that the cuckoo first jettisoned the other eggs or fledglings; others speculated that the foster parents decided to devote themselves to their biggest ‘offspring’ and expelled the others. Jenner, assisted by his young nephew, spent a summer observing the behaviour of female cuckoos and their unwitting hosts around his aunt’s farm in Eastington, Gloucestershire. He wrote up his findings in a paper for the Royal Society (published in 1788), describing the way in which the blind, newly hatched cuckoo expels both eggs and other fledglings from the nest, carrying the burdens in a ‘dent’ in its back which disappears after the first few days of life.
The fellows of the Royal Society apparently did not believe him. The president, Sir Joseph Banks, suggested tactfully that more evidence might be thought to be required, and offered to publish the paper in the following year, giving Jenner ‘a full scope for altering it as you shall choose’. In fact, it was not until a fledgling was filmed in the act in 1922 that all doubt was brought to an end. (F. D. Drewitt in his slim but readable biography of 1931 queried what would happen if the nest were in a more enclosed space with no ‘drop’ for the hapless victims. But presumably once out of the nest itself they would die rapidly anyway?)
As it happens, we have now reissued two biographies of Jenner, the one by Drewitt, author of The Romance of the Apothecaries’ Garden at Chelsea, and the other, in two volumes, by John Baron (1786–1851), who as a disciple of the great man was asked by his family to write his life. As so often with biographies or memoirs published by people who knew their subject well, the advantage of this intimate knowledge has to be weighed against a tendency to hagiography – except of course on the rare occasions when the biographer really has a score to settle, definitely not the case here.
Jenner was the son (the eighth of nine children, only five of whom survived childhood) of the vicar of Berkeley in Gloucestershire (where there is now a Jenner Museum), and was given the name of an elder brother who had died the month before he was born. (The – to us disturbing – custom of naming a baby after a dead sibling was surprisingly commonplace, as is evidenced by family tombstones, and of course it is one of the hinges on which the plot of Hardy’s The Mayor of Casterbridge turns.)
Edward Jenner started his medical career as an apothecary’s apprentice, but in 1770 he went to London and worked under the great John Hunter at St George’s Hospital, and it was at this time that he came into the orbit of Sir Joseph Banks: had the latter gone on Cook’s second voyage, he planned to take Jenner with him as an assistant. As it was, Jenner returned home and set up as a general practitioner, married, and had three children. A well-to-do country physician, on visiting terms with the gentry and minor nobility, writing poetry, making notes on natural history, he showed no obvious signs that he would be responsible for the most important public health breakthrough of the eighteenth century.
Inoculation against smallpox, the disease which, if it did not bring you to an agonising death, would leave you weakened and disfigured, was known in the Middle East, and popularised in Britain by Lady Mary Wortley Montagu in the 1720s. It was effective, but also dangerous, since it involved deliberately infecting a healthy person with matter from the pustules on the skin of a victim. If the patient was only mildly affected, immunity from smallpox would result, but there was still a risk of death, as well as a considerable danger that unprotected people would catch the disease from the inoculated patient during the infectious period.
Famously, Jenner (who remembered his own unpleasant boyhood inoculation) made a link between infection and the apparent immunity from smallpox of milkmaids, which was a well-known country truism. Being infected with cowpox (mild in symptoms and in after-effects) appeared to guarantee that you would not get smallpox. He tried the experiment of using pus from an infected dairymaid to inoculate a healthy eight-year-old boy. He developed cowpox, and quickly recovered. Next, Jenner infected him with smallpox: he did not catch the disease. (Though what an ethics committee would have said is another matter…) A safe and effective form of immunisation against a dread illness had been found.
So far, so familiar from history lessons, but I did not know that most scientists at the time (including the great Sir Joseph) rejected Jenner’s finding when he sent a paper describing the results of several such ‘vaccinations’ (Latin vacca, a cow) to the Royal Society. His results, apparently, did not accord with then current knowledge. Moreover, subsequent attempts by William Woodville to replicate his results were disastrous, as his cowpox pus was in fact contaminated with smallpox.
A war of pamphlets followed, but increasingly both in Europe and in the newly independent United States, physicians adopted Jenner’s process. President Thomas Jefferson had his whole family vaccinated; Marquess Wellesley set up a vaccination programme in India (the life-saving vaccine was acceptable to Hindus because it originated from cows but did not harm them); Lord Elgin promoted it in Greece and Constantinople. Jenner petitioned Napoleon for the release of friends taken prisoner by the French: the emperor could not refuse him, and nor could the king of Spain when similarly approached.
Jenner became the most famous person in England, whom all foreign visitors wanted to meet. Baron lists in an appendix all the honours, medals, degrees, royal gifts, etc. that he received. He continued to promote vaccination at home and abroad: the Royal Jennerian Society (patrons, the entirety of the royal family; president, the duke of Wellington) was founded in 1803 with the purpose of ‘the extermination of the small-pox’, with a ‘plan, regulations, and instructions for vaccine inoculation’. The problem of regulation, to prevent inadequately trained people (or straightforward con-men) from offering vaccination, was difficult to resolve, and there continued to be outbreaks of smallpox which were not contained, because of either failed inoculation, or active infection from contaminated material. Worldwide, the disease was not officially declared eradicated until the 1970s, though effectively it had been eliminated in Europe and North America by 1900.
Jenner himself died in 1823, after a stroke. His wife and oldest son had pre-deceased him, both victims of tuberculosis. Baron’s very detailed biography (and history of smallpox) depicts a modest genius, often frustrated by an obtuse Establishment and denigrated by the jealousy of lesser scientists. In Drewitt’s work, the story of vaccination makes up only about half the book, Jenner’s interest in natural history (which he shared with John Hunter) being possibly more congenial to the author than the medical side. Both show a man, who, having made his life-changing discovery, was thoroughly committed to spreading its use, was intolerant of all opposition, and had the foresight to declare in 1801 that it would one day be possible to eradicate the disease for ever.