17 November, 2014

Edward Jenner - Great Contribution to immunization

Introduction

For many centuries, smallpox devastated mankind. In modern times we do not have to worry about it thanks to the remarkable work of Edward Jenner and later developments from his endeavors. With the rapid pace of vaccine development in recent decades, the historic origins of immunization are often forgotten. Unfortunately, since the attack on the World Trade Center on September 11, 2001, the threat of biological warfare and bioterrorism has reemerged. Smallpox has been identified as a possible agent of bioterrorism . It seems prudent to review the history of a disease known to few people in the 21st century.
Edward Jenner (1749–1823) is well known around the world for his innovative contribution to immunization and the ultimate eradication of smallpox . Jenner's work is widely regarded as the foundation of immunology—despite the fact that he was neither the first to suggest that infection with cowpox conferred specific immunity to smallpox nor the first to attempt cowpox inoculation for this purpose.

Edward Jenner's Work and Life

Figure 1
Edward Jenner was born on May 17, 1749, in Berkeley, Gloucestershire, the son of the Rev. Stephen Jenner, vicar of Berkeley. Edward was orphaned at age 5 and went to live with his older brother. During his early school years, Edward developed a strong interest in science and nature that continued throughout his life. At age 13 he was apprenticed to a country surgeon and apothecary in Sodbury, near Bristol . The record shows that it was there that Jenner heard a dairymaid say, “I shall never have smallpox for I have had cowpox. I shall never have an ugly pockmarked face.” It fact, it was a common belief that dairymaids were in some way protected from smallpox.
In 1764, Jenner began his apprenticeship with George Harwicke. During these years, he acquired a sound knowledge of surgical and medical practice . Upon completion of this apprenticeship at the age of 21, Jenner went to London and became a student of John Hunter, who was on the staff of St. George's Hospital in London. Hunter was not only one of the most famous surgeons in England, but he was also a well-respected biologist, anatomist, and experimental scientist. The firm friendship that grew between Hunter and Jenner lasted until Hunter's death in 1793. Although Jenner already had a great interest in natural science, the experience during the 2 years with Hunter only increased his activities and curiosity. Jenner was so interested in natural science that he helped classify many species that Captain Cook brought back from his first voyage. In 1772, however, Jenner declined Cook's invitation to take part in the second voyage .
Jenner occupied himself with many matters. He studied geology and carried out experiments on human blood . In 1784, after public demonstrations of hot air and hydrogen balloons by Joseph M. Montgolfier in France during the preceding year, Jenner built and twice launched his own hydrogen balloon. It flew 12 miles. Following Hunter's suggestions, Jenner conducted a particular study of the cuckoo. The final version of Jenner's paper was published in 1788 and included the original observation that it is the cuckoo hatchling that evicts the eggs and chicks of the foster parents from the nest . For this remarkable work, Jenner was elected a fellow of the Royal Society. However, many naturalists in England dismissed his work as pure nonsense. For more than a century, antivaccinationists used the supposed defects of the cuckoo study to cast doubt on Jenner's other work. Jenner was finally vindicated in 1921 when photography confirmed his observation . At any rate, it is apparent that Jenner had a lifelong interest in natural sciences. His last work, published posthumously, was on the migration of birds.
In addition to his training and experience in biology, Jenner made great progress in clinical surgery while studying with John Hunter in London. Jenner devised an improved method for preparing a medicine known as tartar emetic (potassium antimony tartrate). In 1773, at the end of 2 years with John Hunter, Jenner returned to Berkeley to practice medicine. 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 . He also played the violin in a musical club and wrote light verse and poetry. As a natural scientist, he continued to make many observations on birds and the hibernation of hedgehogs and collected many specimens for John Hunter in London.
While Jenner's interest in the protective effects of cowpox began during his apprenticeship with George Harwicke, it was 1796 before he made the first step in the long process whereby smallpox, the scourge of mankind, would be totally eradicated. For many years, he had heard the tales that dairymaids were protected from smallpox naturally after having suffered from cowpox. Pondering this, Jenner concluded that cowpox not only protected against smallpox but also could be transmitted from one person to another as a deliberate mechanism of protection. In May 1796, Edward Jenner found a young dairymaid, Sarah Nelms, who had fresh cowpox lesions on her hands and arms. On May 14, 1796, using matter from Nelms' lesions, he inoculated an 8-year-old boy, James Phipps. Subsequently, the boy developed mild fever and discomfort in the axillae. Nine days after the procedure he felt cold and had lost his appetite, but on the next day he was much better. In July 1796, Jenner inoculated the boy again, this time with matter from a fresh smallpox lesion. No disease developed, and Jenner concluded that protection was complete.
Figure 3
The hand of Sarah Nelms.
In 1797, Jenner sent a short communication to the Royal Society describing his experiment and observations. However, the paper was rejected. Then in 1798, having added a few more cases to his initial experiment, Jenner privately published a small booklet entitled An Inquiry into the Causes and Effects of the Variolae Vaccinae, a disease discovered in some of the western counties of England, particularly Gloucestershire and Known by the Name of Cow Pox . The Latin word for cow is vacca, and cowpox is vaccinia; Jenner decided to call this new procedure vaccination. The 1798 publication had three parts. In the first part Jenner presented his view regarding the origin of cowpox as a disease of horses transmitted to cows. The theory was discredited during Jenner's lifetime. He then presented the hypothesis that infection with cowpox protects against subsequent infection with smallpox. The second part contained the critical observations relevant to testing the hypothesis. The third part was a lengthy discussion, in part polemical, of the findings and a variety of issues related to smallpox. The publication of the Inquiry was met with a mixed reaction in the medical community.
Jenner went to London in search of volunteers for vaccination. However, after 3 months he had found none. In London, vaccination became popular through the activities of others, particularly the surgeon Henry Cline, to whom Jenner had given some of the inoculant . Later in 1799, Drs. George Pearson and William Woodville began to support vaccination among their patients. Jenner conducted a nationwide survey in search of proof of resistance to smallpox or to variolation among persons who had cowpox. The results of this survey confirmed his theory. Despite errors, many controversies, and chicanery, the use of vaccination spread rapidly in England, and by the year 1800, it had also reached most European countries.
Although sometimes embarrassed by a lack of supply, Jenner sent vaccine to his medical acquaintances and to anyone else who requested it. After introducing cowpox inoculation in their own districts, many recipients passed the vaccine on to others. Dr. John Haygarth (of Bath, Somerset) received the vaccine from Edward Jenner in 1800 and sent some of the material to Benjamin Waterhouse, professor of physics at Harvard University. Waterhouse introduced vaccination in New England and then persuaded Thomas Jefferson to try it in Virginia. Waterhouse received great support from Jefferson, who appointed him vaccine agent in the National Vaccine Institute, an organization set up to implement a national vaccination program in the United States .
Although he received worldwide recognition and many honors, Jenner made no attempt to enrich himself through his discovery. He actually devoted so much time to the cause of vaccination that his private practice and his personal affairs suffered severely. The extraordinary value of vaccination was publicly acknowledged in England, when in 1802 the British Parliament granted Edward Jenner the sum of £10,000. Five years later the Parliament awarded him £20,000 more. However, he not only received honors but also found himself subjected to attacks and ridicule. Despite all this, he continued his activities on behalf of the vaccination program. Gradually, vaccination replaced variolation, which became prohibited in England in 1840.
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. After a decade of being honored and reviled in more or less equal measure, he gradually withdrew from public life and returned to the practice of country medicine in Berkeley. In 1810, his oldest son, Edward, died of tuberculosis. His sister Mary died the same year and his sister Anne 2 years later. In 1815, his wife, Catherine, died of tuberculosis . Sorrows crowded in on him, and he withdrew even further from public life. In 1820, Jenner had a stroke from which he recovered. On January 23, 1823, he visited his last patient, a dying friend. The next morning Jenner failed to appear for breakfast; later that day he was found in his study. He had had a massive stroke. Edward Jenner died during the early morning hours of Sunday, January 26, 1823. He was laid to rest with his parents, his wife, and his son near the altar of the Berkeley church.

Conclusion

Jenner's work represented the first scientific attempt to control an infectious disease by the deliberate use of vaccination. Strictly speaking, he did not discover vaccination but was the first person to confer scientific status on the procedure and to pursue its scientific investigation. During the past years, there has been a growing recognition of Benjamin Jesty (1737–1816) as the first to vaccinate against smallpox . When smallpox was present in Jesty's locality in 1774, he was determined to protect the life of his family. Jesty used material from udders of cattle that he knew had cowpox and transferred the material with a small lancet to the arms of his wife and two boys. The trio of vaccinees remained free of smallpox, although they were exposed on numerous occasions in later life. Benjamin Jesty was neither the first nor the last to experiment with vaccination. In fact, the use of smallpox and cowpox was widely known among the country physicians in the dairy counties of 18th-century England. However, the recognition of these facts should not diminish our view of Jenner's accomplishments. It was his relentless promotion and devoted research of vaccination that changed the way medicine was practiced.



Posted by
Garima Sharma

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