Thursday, March 17, 2011

Edward Jenner: The Smallpox Vaccine

Great Advances in Science

I hope that some day the practice of producing cowpox in human beings will spread over the world — when that day comes, there will be no more smallpox.
Edward Jenner on the smallpox vaccine

The joy I felt as the prospect before me of being the instrument destined to take away from the world one of its greatest calamities (smallpox) was so excessive that I found myself in a kind of reverie
Edward Jenner

Making a discovery may never come or it may take a long time and only come to fruition after your death—it is a privilege to make a real difference in your own life time
Edward Jenner

Edward Jenner [1749-1823]:  Portrait by James Northcote, oil on canvas, 1803, 1823: English general practioner and surgeon, and known as the Father of Immunology, Jenner essentially used the scientific method to develop the first modern vaccine for smallpox. As Jenner said: I shall endeavour further to prosecute this inquiry, an inquiry I trust not merely speculative, but of sufficient moment to inspire the pleasing hope of its becoming essentially beneficial to mankind."
Photo Credit: © National Portrait Gallery, London

Edward Jenner is considered the father of immunology, earning that distinction as the inventor of the first modern vaccine for smallpox (also called variola), a disease with debilitating if not deadly consequences. The term smallpox was first used in Europe in the 15th century to distinguish variola from the great pox of syphilis.

Nevertheless, despite its lesser stature in the lexicon of infectious diseases, in the period during Edward Jenner's birth in eighteenth century England, many people were dying from smallpox, and the great majority children.

The disease killed an estimated 400,000 Europeans per year during the closing years of the 18th century, including five reigning monarchs. It was responsible for a third of all blindness. And, even if persons survived this disease, many would suffer horrible disfiguring scars on their faces, the characteristic pockmarks.

As with many diseases, it was no respecter of persons, power or position. Smallpox killed Queen Mary II of England, Emperor Joseph I of Austria, King Luis I of Spain, Tsar Peter II of Russia, Queen Ulrika Elenora of Sweden, and King Louis XV of France.

Or to put it more bluntly: Smallpox killed more people than any disease in history. One-third of its victims died from the disease. "Smallpox killed more people than the Black Death and all the wars of the twentieth century combined; about five hundred million people died from the disease," Paul Offit, M.D., wrote in Deadly Choices: How The Anti-Vaccine Movement Threatens Us All.

Such clearly and urgently explained the importance of the smallpox vaccine. What is fascinating is the way Jenner found his way to discovering the relationship between cowpox and the more deadly smallpox. What Jenner discovered, initially through a milkmaid's observations, is that a person injected with an attenuated (weakened) cowpox virus was vaccinated against the more deadly smallpox disease.

It was an observation that was not easily apparent and went against the conventional wisdom of the time. Imagination married to verifiable observations is often necessary in all new breakthrough discoveries.

So, it's not surprising that it made little sense to the scientifically untrained mind to inject a known virus (cowpox) into a human being and reap a viable benefit. The scientific community was cautious, if not somewhat skeptical. But such is often the strangeness of scientific advancement, and yet the benefits of vaccines have been proven the last two hundred years.

The Formative Years

Edward Jenner was born to Stephen Jenner and a unnamed woman (a daughter of the Reverend Henry Head, a former vicar of Berkeley), in Berkeley, Gloucestershire, England on May 18,1749. Edward was the third son and youngest of six children born to the couple. The father was a clergyman of the Church of England, rector of Rockhampton and vicar of Berkeley, a small market town in the Servern Valley.

In addition to his church offices, Jenner's father owned a considerable amount of land in the vicinity of Berkeley. The son of a local vicar he was interested in natural history and medicine from an early age. Both his parents died within weeks of each other when the young Jenner was only five. He was brought up by an older brother, Reverend Stephen Jenner, also a clergyman. As the Encyclopedia Britannica says:
Edward acquired a love of nature that remained with him all his life. He attended grammar school and at the age of 13 was apprenticed to a nearby surgeon. In the following eight years Jenner acquired a sound knowledge of medical and surgical practice.

On completing his apprenticeship at the age of 21, he went to London and became the house pupil of John Hunter, who was on the staff of St. George’s Hospital and was one of the most prominent surgeons in London. Even more important, however, he was an anatomist, biologist, and experimentalist of the first rank; not only did he collect biological specimens, but he also concerned himself with problems of physiology and function.
When he studied at St George's Hospital under surgeon John Hunter. Jenner was influenced by his philosophy of seeking new discoveries with the idea—"Don't Think, Try"— a series of trial and errors, essentially today's scientific method:

In 1773, after two years of study under Hunter, Jenner returned to his native Berkeley in southern England to become a general practitioner. There he enjoyed substantial success, for he was capable, skillful, and popular. In addition to the practice of medicine, he joined two local medical groups for the promotion of medical knowledge and continued to write occasional medical papers. In his spare time, he pursued his study of native wildlife and also kept abreast of new developments in medical science.

The First Modern Vaccine

For many years, Jenner had heard stories that dairymaids were protected from smallpox naturally after having suffered from cowpox. After having observed this himself, he decided to test that observation. Opportunity soon came. Sarah Nelms, a young dairymaid had fresh cowpox lesions on her hands and armsand James Phipps, the eight-year-old son of a local labourer became the subject of the experiment. On May 14, 1796, Jenner extracted fluid from Nelms' lesions, and carried out his now famous experiment, the BBC archives reports:
Jenner inserted pus taken from a cowpox pustule [of Sarah Nelms] and inserted it into an incision on the boy's arm. He was testing his theory, drawn from the folklore of the countryside, that milkmaids who suffered the mild disease of cowpox never contracted smallpox, one of the greatest killers of the period, particularly among children. Jenner subsequently proved that having been inoculated with cowpox Phipps was immune to smallpox. 
He did this by injecting Phipps on July 1, 1796, with pus taken from someone with smallpox. Phipps survived. With such wonderful results, a medical breakthrough, he was encouraged to have its results widely reported so others would benefit. Accordingly, Jenner submitted a paper to the Royal Society in 1797 describing his experiment. He told that his ideas were too revolutionary and that he needed more proof. Determined, Jenner experimented on several other children, including his own 11-month-old son.

In 1798, the results were finally published in a monograph, Inquiry into the Causes and Effects of the Variolae Vaccine. Jenner coined the word vaccination from the Latin vaccinae, "of the cow." Jenner had developed the first modern vaccine.

The Anti-Vaccine Lobby: In this cartoon from June 12 1802, the British satirist James Gillray caricatured a scene at the Smallpox and Inoculation Hospital at St. Pancras, showing Edward Jenner administering cowpox vaccine to frightened young women, and cows emerging from different parts of people's bodies. The cartoon was inspired by the controversy over inoculating against the dreaded disease, smallpox. The inoculation agent, cowpox vaccine, was rumored to have the ability to sprout cow-like appendages.
Source: U.S. Library of Congress Prints and Photograph Division: Washington
The Modern Anti-Vaccine Movement

The public response, perhaps not surprising, was less generous than Jenner expected. Jenner was widely ridiculed and he and his theories attacked for being against the tenets of Christianity. Critics, especially the clergy, claimed it was repulsive and ungodly to inoculate someone using with material from a diseased animal. James Gillray's satirical cartoon in 1802 (above) portrayed people who had been vaccinated sprouting cow's heads.

Of course, it was pure nonsense and an example of the power of fear-mongering when in the hands of those both scientifically ignorant and scientifically illiterate. (Such battles still take place today, and for similar reasons. See, for example, Improving Scientific Literacy and On Vaccines: A Matter of Life,)

Even so, science and good reason eventually prevailed, when the obvious advantages of vaccination and the protection it provided won out, and vaccination soon became widespread. Jenner became famous and now spent much of his time researching and advising on developments in his vaccine.

Jenner married in 1788 and fathered four children. The family lived in the Chantry House, which became the Jenner Museum in 1985. Jenner built a one-room hut in the garden, which he called the “Temple of Vaccinia," where he vaccinated the poor for free.

For example, 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 when it was formed in 1805, to whom it presented a number of papers. This is now the Royal Society of Medicine. In 1806, he was elected a foreign member of the Royal Swedish Academy of Sciences.

After ten years of public service, where he was hailed and reviled in equal measure, Jenner withdrew from public life. Then tragedy overtook him in the disease of tuberculosis. In 1810, his oldest son, Edward, died of tuberculosis at at the age of twenty-one. His sister Mary died the same year and his sister Anne two years later. In 1815, his wife, Catherine, also died of tuberculosis.

Eventual Eradication of Smallpox

Edward Jenner suffered a stroke on January 24, 1923, and died in Berkeley, Gloucestershire, two days later on Sunday January 26, 1823. He was 73. He was buried with his parents, his wife, and his son near the altar of the Berkeley church.

His contribution to science and the betterment of humanity in indisputable.But it took time for the once deadly disease to be eradicated, the World Health Organization reports:
In the early 1950s —150 years after the introduction of vaccination — an estimated 50 million cases of smallpox occurred in the world each year, a figure which fell to around 10–15 million by 1967 because of vaccination.

In 1967, when WHO launched an intensified plan to eradicate smallpox, the "ancient scourge" threatened 60% of the world's population, killed every fourth victim, scarred or blinded most survivors, and eluded any form of treatment. Through the success of the global eradication campaign, smallpox was finally pushed back to the horn of Africa and then to a single last natural case, which occurred in Somalia in 1977
That last reported case of smallpox was of an unvaccinated hospital cook in Somalia on October 26, 1977. The World Health Organization declared smallpox an eradicated disease in 1980, one of only two having achieved that distinction, the other being Rinderpest, or cattle plague  Since then routine vaccinations for smallpox are no longer given.

We can thank the Father of Immunology, Edward Jenner.

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