Edward Jenner



Edward Jenner was an English physician, immunologist, and zoologist. He is often erroneously credited with developing the world's first vaccine. His work on smallpox, was a major step forward in combating what was arguably the most deadly disease in human history. In a 2002 BBC poll, he was ranked the 78th greatest Briton of all time.

Early life
Edward Jenner was born in Berkeley, Gloucestershire. At age 8, he was inoculated with cowpox for prevention of smallpox infection. He received a basic primary education before beginning an apprenticeship with a surgeon at the age of 14. In his early 20s, he began another apprenticeship at St George's, University of London to continue his study of surgery and general human anatomy. In 1772 he earned his M.D. from the University of St Andrews and went on to become a successful general practitioner and surgeon. He later became a member of the Royal Society in 1788 where he published groundbreaking new research on the behavior of the cuckoo bird and its life history strategy.

Smallpox
Smallpox's origins are unclear. Reports of smallpox appear in ancient texts of China India and and was likely found on the mummy of pharaoh Ramses V in Egypt, all about 3000 years ago. Since then, it repeatedly ravaged different parts of the world in devastating outbreaks. During the 20th century as many as 300 million people were killed by it. After 1492, when first introduced to the Americas, it contributed to the deaths of about 54 million people. In medieval Europe, China and India, it killed hundreds of thousands of people every year, leaving many of its survivors blind, scarred, or both.

Variolation
Before modern vaccines, there was variolation, which seems to date back to around the year 1000 CE in China, although precise references to smallpox immunization don't appear until a few hundred years later. The terms 'variolation' and 'smallpox vaccination' are synonymous because the word 'variolation' is derived from the synonym for smallpox, 'variola'; 'variolation' is only used in reference to smallpox, whereas 'vaccination' can apply to a wide range of diseases.

Variolation was a practice in which people were intentionally exposed to a mild form of the disease. Scabs were taken from a cow with cowpox or a person with smallpox, powdered into dust and then inhaled through the nose of uninfected people. Occasionally, more direct contact was made by rubbing the powdered scabs or even pustule fluids into a shallow cut. Over time, the practice spread West across Eurasia into Africa and eventually Europe. Those inoculated had lower rates of death than the untreated but there were some serious deficiencies. People who were treated often still carried a live virus, meaning they became a potential walking biohazard who could infect others if not quarantined for a time.

Jenner's contribution
Jenner had actually been variolated in his youth before going on to study medicine himself. The practice was first introduced to Europe in the early 18th century where it was met with skepticism but was eventually practiced. In 1706, an enslaved African named informed  his slave owner in Massachusetts, about the method of variolation for smallpox that he had received when he lived in Africa. Mather later convinced a physician, Zabdiel Boylston, to conduct a variolation experiment during a 1721 smallpox outbreak in Boston. Mather and Boylston then used a statistical analysis to demonstrate the efficacy of variolation at preventing smallpox deaths: the fatality rate among non-variolated people who contracted smallpox was 14% vs. variolated people at 2%.

By 1768, English physician John Fewster had noticed that people who had been struck with cowpox were immune to smallpox. This fact had been known in several countries by people tending cattle, in England, and indigenous people of Mexico.

Noting the common observation that milkmaids were generally immune to smallpox, Jenner theorized that the pus in the blisters that milkmaids received from cowpox immunized them to smallpox. Jenner hypothesized that exposure to cowpox would protect people from smallpox.

In 1796, Jenner tested his hypothesis by inoculating one James Phipps, the eight-year son of his gardener. He acquired pus from cowpox blisters on the hands of a milkmaid who had caught cowpox from a cow. Phipps was the 17th case described in Jenner's first paper on vaccination. Jenner inoculated Phipps in both arms that day, resulting in a fever and some uneasiness, but no full-blown infection. Later, he injected Phipps with variolous material, the routine method of immunization at that time. No disease followed. The boy was later challenged with variolous material and again showed no sign of infection. Jenner went on to successfully test his hypothesis on 23 additional subjects.

Jenner continued his research and reported it to the Royal Society, which did not publish the initial paper. After revisions and further investigations, he published his findings on the 23 cases, including his own infant son Robert. Eventually, vaccination was accepted, and in 1840, the British government fully banned variolation with smallpox and began providing vaccination using cowpox free of charge.

The success of his discovery soon spread around Europe after some initial hesitancy.

Later life and legacy
I avail myself of this occasion of rendering you a portion of the tribute of gratitude due to you from the whole human family. Medicine has never before produced any single improvement of such utility. Jenner continued to pursue and encourage research and experimentation to study and improve his vaccine for the remainder of his life. He died at age 73 due to a complications from internal bleeding and eventually a stroke. His keen use of the scientific method; observation, experimentation, inquisitiveness, cross-disciplinary learning, served as a major breakthrough in modern medicine. In many ways he represents the best of the Enlightenment and Scientific Revolution, helping pave the way for later scientists like Louis Pasteur while simultaneously helping untold numbers of people by making breakthroughs in applied science. Smallpox was officially declared to have been fully eradicated in 1980, Jenner helped take some of the earliest steps toward making that happen.