Benjamin Jesty has not been dealt a fair hand by history. By rights, it should be his name that appears in all the textbooks as the inventor of vaccination, but the credit has long been assigned to Edward Jenner.
Little is known about Jesty's early life, except that he was baptized on 19th August 1736 at Yetminster in north Dorset, the youngest son of a local butcher. He married Elizabeth Notley in March 1770, and lived at Upbury Farm, next to the church at Yetminster. The couple eventually had four sons and three daughters. Benjamin kept cattle on his farm and employed two milkmaids to milk the cows twice a day.
At the time, smallpox was a killer disease that was rife throughout the country, with periodic outbreaks that killed hundreds of people (about 20% of those who caught it) and left disfiguring pockmarks on those who survived. There was also a much milder form of the disease, known as cowpox, that was caught from the udders of infected cattle but, unlike smallpox, was not infectious between humans. It had long been known that people who worked closely with cattle, such as milkmaids, were virtually immune from smallpox. Milkmaids were much sought after by young men in country districts because of their fair, unblemished complexions, Jesty's maids being no exception. He was not alone in wondering if there was a connection between the maids' (and his own) contact with cowpox and their apparent immunity from smallpox, even when they nursed smallpox victims, which both maids had done and he had done himself.
In 1774, with a smallpox epidemic at its height, Jesty took the bold step of deliberately infecting with cowpox his wife and two sons (the rest of the family were born later), none of whom had had cowpox up to that date. His method was to take pox matter from an infected cow's udder on to a needle and then scratch the arms of his subjects with the "dirty" needle. The two boys suffered only mild reactions, but Elizabeth Jesty's arm became very inflamed and gave cause for concern for a time. However, none of them caught smallpox, despite being exposed to the disease.
The fact that material from cows was used to perform the operation was why the term "vaccination" was given to the process (in 1802), "vacca" being the Latin for cow. However, the use of non-human matter caused problems for Jesty when his experiments became known about in the locality, and he was for a time spat at by villagers who accused him of debasing human blood by introducing an animal disease. People who had been treated by Jesty were looked at with curiosity by their neighbors in case they started to grow horns!
Jesty's experiments became known about more widely, and Edward Jenner conducted his own investigations, beginning in 1796, some 22 years after the work of Benjamin Jesty. There is some doubt as to whether Jenner knew about Jesty's work, and therefore whether Jenner does or does not deserve the credit for discovering vaccination. It is true that Benjamin Jesty was a simple Dorset farmer, and therefore wrote no scientific papers that later researchers could work from, but it was also the case that Edward Jenner, as well as being a country doctor, was from the class of minor gentry, and thus more likely to be given any credit that was on offer. He also performed his experiments in a more scientific way, and published his results in 1798 in a scientific paper. Science tends to ascribe discoveries to the people who are first to get them into print.
That said, Benjamin Jesty was encouraged to continue his experiments, particularly after he moved to Worth Matravers, in south Dorset, in 1797. He found a champion in Andrew Bell, the rector of nearby Swanage, and in 1802 his work was recognised by the House of Commons with a very handsome reward of 10,000 pounds. Andrew Bell wrote to the Vaccine Pock Institute with a full account of Jesty's early experiments, and the Institute subsequently invited him to give his evidence in London, where he was warmly received and given an award. The Institute also commissioned a portrait of Benjamin Jesty. It cannot therefore be said that Jesty's contemporaries completely ignored his efforts, although later generations have tended to do so.
Benjamin Jesty died in 1816 at Worth Matravers, where his gravestone can be seen to this day. It reads:
"Sacred to the memory of Benjamin Jesty of Downshay, who departed this life April 16th 1816, aged 79 years. He was born at Yetminster in this county and was an upright honest man, particularly noted for being the first person (known) that introduced the cow pox by inoculation, and who from his great strength of mind made the experiment on his wife and two sons in the year 1774"
Nothing is said about whether the wife and two sons were quite as happy about the idea!
The question remains about whether posterity has been fair to Benjamin Jesty, for the reasons mentioned above. The debate between the rival claims of Jesty and Jenner is similar to that over the theory of natural selection, as between Charles Darwin and Alfred Russel Wallace. In both cases, it was the man who published first who gained the credit, whether or not the idea had been theirs first.
One difficulty for Jesty's claim to fame is that he did not approach the matter from a scientific viewpoint but from the application of nothing more than logic. Experiments in inoculation had taken place before Jesty's experiment, but these had involved using material from smallpox pustules on healthy subjects. This practice was banned in many places for fear that it would spread the disease rather than cure it, and it was certainly not a proven technique.
Whether Jesty was aware of such work is unclear, but it is almost certain that he never read a scientific paper before 1774, and probably not afterwards either. What he did was simply to say to himself: "People with cowpox do not die. People with smallpox often do. People who have had cowpox do not get smallpox. So if I give someone cowpox they will not get smallpox, and there is no chance that they will die." His experiment was therefore carried out with the certainty that it would succeed, and he would not have seen himself as risking the lives of his family members. It is quite possible that the bad reaction suffered by his wife had more to do with blood poisoning caused by other organisms than the cowpox, as it is probably unwise to scrape a needle on a cow's udder in a country milking parlor and then scratch somebody's arm with the same needle. Had Benjamin Jesty had any knowledge of how infections enter the bloodstream, it is unlikely that he would have taken the chance. As it was, his logical thinking outweighed his scientific ignorance, and his named should be remembered, alongside that of Edward Jenner, for that reason.