Edward Jenner and the Search for the Smallpox Vaccine in the 18th Century


Edward Jenner in the prime of his studies / Wikimedia Commons

His work led to systematically developing, testing, and popularizing inoculation that saved countless lives.


Edited by Matthew A. McIntosh
Journalist and Historian
Brewminate Editor-in-Chief


Introduction

Edward B. Jenner (May 17, 1749 – January 26, 1823) was an English physician and scientist who is most recognized for introducing and popularizing an effective and relatively safe means of vaccination against smallpox, a discovery that proved to be one of the most significant medical advances of all time.

Although inoculations using dried smallpox secretions had been known for centuries in China and had spread to the Ottoman Empire and then England before Jenner’s time, his vaccine utilizing material from a cowpox lesion was safer, more effective, and without the risk of smallpox transmission. Vaccination to prevent smallpox was soon practiced all over the world. Eventually, a disease that had killed many hundreds of millions, and disfigured and blinded countless more, was completely eradicated. It is the only infectious disease in humans that has been completely eradicated.

Jenner also coined the term immunization, which in its original meaning specifically referred to the protection conferred against smallpox using material from cowpox virus. Jenner called the material used for inoculation “vaccine,” from the root word vacca, which is Latin for cow.

Jenner also was a naturalist, who studied his natural surroundings in Berkeley, Gloucestershire, in rural England; was a horticulturist; and discovered the fossils of a plesiosaur. He became a Fellow of the Royal Society based on his study of the nesting habits of the cuckoo.

Although Jenner was not the first to discover the practice of inoculation, and even the use of cowpox as vaccine predated him, his leadership and intellectual qualities lead to systematically developing, testing, and popularizing this method that saved countless lives. Ironically, the first experiment he performed, on a young boy, would be considered unethical by current standards, but lead to major benefit for humanity.

Early Life

Jenner trained in Chipping Sodbury, Gloucestershire as an apprentice to John Ludlow, a surgeon, for eight years from the age of 13. In 1770, Jenner went up to London to study surgery and anatomy under the surgeon John Hunter and others at St George’s, University of London. Hunter was the preeminent medical teacher in Britain (Last 2002), a noted experimentalist, and later a fellow of the Royal Society.

William Osler records that Jenner was a student to whom Hunter repeated William Harvey’s advice, very famous in medical circles (and characteristically Enlightenment), “Don’t think, try.” Jenner, therefore, was noticed early by men famous for advancing the practice and institutions of medicine. Hunter remained in correspondence with him over natural history and proposed him for the Royal Society. Returning to his native countryside by 1773, he became a successful general practitioner and surgeon, practicing in purpose-built premises at Berkeley.

Jenner and others formed a medical society in Rodborough, Gloucestershire, meeting to read papers on medical subjects and dine together. Jenner contributed papers on angina pectoris, ophthalmia, and valvular disease of the heart and commented on cowpox. He also belonged to a similar society which met in Alveston, near Bristol (RCP).

He was elected Fellow of the Royal Society in 1788, following a careful study combining observation, experiment, and dissection into a description of the previously misunderstood life of the cuckoo in the nest.

Common Cuckoo / Wikimedia Commons

Jenner’s description of the newly-hatched cuckoo pushing it’s host’s eggs and fledglings from the nest was confirmed in the twentieth century (JM) when photography became feasible. Having observed the behavior, he demonstrated an anatomical adaptation for it—the baby cuckoo has a depression in its back that is not present after 12 days of life, in which it cups eggs and other chicks to push them out of the nest. It had been assumed that the adult bird did this but the adult does not remain in the area for sufficiently long. His findings were published in the Philosophical Transactions of the Royal Society in 1787.

He married Catherine Kingscote (died 1815 from tuberculosis) in March 1788 having met her when balloons were hot science, and he and other Fellows were experimenting with them. His trial balloon descended into Kingscote Park, owned by Anthony Kingscote, Catherine being one of his three daughters.

Jenner did not take any examinations to receive his medical degree, but purchased a medical degree in 1792, from a Scottish University, the University of St. Andrews, and subsequently would apply for a degree from Oxford University, which he was granted (Last 2002).

Smallpox

Smallpox at one time was a very deadly disease, that is estimated to have killed 400,000 Europeans each year during the 18th century (including five reigning monarchs), and was responsible for a third of all blindness (Behbehani 1983). Between 20 to 60 percent of all those infected—and over 80 percent of infected children—died from the disease (Riedel 2005). During the twentieth century, it is estimated that smallpox was responsible for 300 to 500 million deaths (Koplow 2003).

A method of inoculating against smallpox was known from Asia centuries before Jenner. Basically, when the human immune system is exposed to a disease once, it can develop the ability to quickly respond to a subsequent infection. Therefore, by exposing an individual to an immunogen in a controlled way, the person’s body will then be able to protect itself from infection later on in life. One does not necessarily have to be exposed to the natural infection, but exposure to a similar agent can confer an increased resistance to the disease.

Recognizing that an infectious disease, once overcome, did not normally reappear, people have tried to prevent getting a disease by purposely inoculating themselves with infected material. This is considered to have first been done successfully with smallpox before 200 B.C.E. (NMAH 2007), and having been practiced in India as early as 1000 B.C.E. (Bourzac 2002). However, this idea of such an early treatment has been challenged and the earliest confirmed inoculations are from China around 1000 C.E. (Last 2002), and were widely practiced during the Ming Dynasty (Temple 1986).

These early inoculations involved the process of variolation, involving either nasal insufflation of powdered smallpox scabs, or scratching material from a smallpox lesion into the skin. However, because the person was actually infected with the virus, a severe infection could result, and the person could transmit smallpox to others. However, the mortality rate was much less than the contracting the disease itself.

From China, this practice of variolation spread along the silk route, reaching Asia Minor sometime in the seventeenth century. In 1718, Lady Mary Wortley Montague, wife of the British ambassador to the Ottoman Empire, reported that the Turks have a habit of deliberately inoculating themselves with fluid taken from mild cases of smallpox and she inoculated her own children (Behbehani 1983). She imported this idea to England when she returned home, and many educated English families used this method to offer some protection against smallpox (Last 2002). Jenner himself was inoculated at a young age (Gross and Sepkowitz 1998).

Around the time of Jenner, smallpox was greatly feared, as one in three of those who contracted the disease died, and those who survived were often badly disfigured. Voltaire recorded that 60.243 percent of people caught smallpox, with 20 percent of the population dying of it.

It was noticed by many that people who had been infected with cowpox, a milder relative of the smallpox virus, did not get smallpox. After 1770, there were at least several people in England and Germany (Sevel, Jensen, Jesty 1774, Rendall, Plett 1791) who had successfully tested the possibility of using the cowpox vaccine as an immunization for smallpox in humans (Plett 2006).

1802 caricature of Jenner vaccinating patients who feared it would make them sprout cowlike appendages. / Wikimedia Commons

In 1774, during a smallpox epidemic, Dorset farmer, Benjamin Jesty had successfully induced immunity in his wife and two children with cowpox. There was a popular belief that people infected and recovered from cowpox did not get smallpox, and Jesty noticed that “milkmaids” did not become infected with smallpox, or displayed a milder form. Jestey took the pus from an infected cow’s udder and inoculated his wife and children with cowpox.

It is not known whether Jenner had the advantage of hearing stories of Jesty and perhaps others deliberately arranging cowpox infection of their families and of a reduced risk in those families. However, noting the common observation that milkmaids did not generally get smallpox, Jenner theorized that the pus in the blisters that milkmaids received from cowpox protected the milkmaids from smallpox.

On 14 May 1796, Jenner tested his theory by inoculating James Phipps, a young boy of 8 years old, with material from the cowpox blisters of the hand of Sarah Nelmes, a milkmaid who had caught cowpox from a cow called Blossom (JM). Blossom’s hide now hangs on the wall of the library at St George’s medical school (now in Tooting), in commemoration of one of the school’s most renowned alumni. Phipps was the 17th case described in Jenner’s first paper on vaccination.

Jenner inoculated Phipps with cowpox pus in both arms on one day, by scraping the pus from Nelmes’ blisters onto a piece of wood then transferring this to Phipps’ arms. This produced a fever and some uneasiness but no great illness. Later, he injected Phipps with variolous material, which would have been the routine attempt to produce immunity at that time. No disease followed. Jenner reported that later the boy was again challenged with variolacious material and again showed no sign of infection.

He continued his research and reported it to the Royal Society, who did not publish the initial report. After improvement and further work, he published a report of twenty-three cases, mostof theim children that he had inoculated, all of whom survived unharmed and did not get smallpox. Some of Jenner’s conclusions were correct, and some erroneous. The medical establishment, as cautious then as now, considered his findings for some time before accepting them. Eventually vaccination was accepted, and in 1840, the British government banned variolation and provided vaccination free of charge.

Later Life

Jenner’s continuing work on vaccination prevented his continuing his ordinary medical practice. He was supported by his colleagues and the King in petitioning Parliament and was granted £10,000 for his work on vaccination. In 1806, he was granted another £20,000 for his continuing work.

In 1803, in London, he became involved with the Jennerian Institution, a society concerned with promoting vaccination to eradicate smallpox. In 1808, with government aid, this society became the National Vaccine Establishment. Jenner became a member of the Medical and Chirurgical Society on its foundation in 1805, and subsequently presented to them a number of papers. This is now the Royal Society of Medicine.

Returning to London in 1811, Jenner observed a significant number of cases of smallpox after vaccination occurring. He found that in these cases the severity of the illness was notably diminished by the previous vaccination. In 1821, he was appointed Physician Extraordinary to King George IV, a considerable national honor, and was made Mayor of Berkeley and Justice of the Peace. He continued his interests in natural history. In 1823, the last year of his life, he presented his Observations on the Migration of Birds to the Royal Society.

He was found in a state of apoplexy on 25 January 1823, with his right side paralyzed. He never rallied, and died of what was apparently a stroke (he had suffered a previous stroke) on January 26, 1823 at the age of 73. He was survived by one son and one daughter, his elder son having died of tuberculosis at the age of 21.

Legacy

Bronze statue of Jenner in Kensington Gardens / Wikimedia Commons

In 1980, the World Health Organization declared smallpox an eradicated disease. This was the result of coordinated public health efforts by many people, but vaccination was an essential component. Although it was declared eradicated, some samples still remain in laboratories in Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia in the United States, and State Research Center of Virology and Biotechnology VECTOR in Koltsovo, Novosibirsk Oblast, Russia.

References


Originally published by New World Encyclopedia, 05.07.2014, under a Creative Commons Attribution-ShareAlike 3.0 Unported license.

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