For many centuries, smallpox took toll of humankind. It is estimated that over 400,000 people died in just Europe in the 18th century. These included the deaths of four reigning monarchs and a queen. It was endemic in every European country at the end of the 19th century. It is estimated that over 500 million people have been swept off by this disease in the past 100 years.
However, in modern times we do not have to worry about it. This is because we have been successful in its complete eradication in 1977 (this is the only disease which has been successfully eradicated from the planet). All the credit for this remarkable work goes to the power of observation and scientific scrutiny of an English Physician named Edward Jenner and later developments from his endeavors.
The sole reason that smallpox became such havoc was the fact that there was never a treatment available for it. Once a person became infected, it was impossible to treat him; one could helplessly let the disease run its course. Few people, who survived this course never, caught it again. During, mid-18th century, another method came, called inoculation (sometimes also variolation). In this method, a person was deliberately infected with a viral matter. It posed many disadvantages. First, during the course of mild infection, there is a definite possibility that a person becomes a carrier of the disease and infects other people. Second, it was difficult to control the severeness of the disease and sometimes the infection resulted in the death of the person. Jenner himself was inoculated with smallpox at the age of 8 and hence was immune to the disease.
Working in an agricultural community, he was well aware of the country folklore which stated that milkmaids never caught smallpox. However, because of their close proximity with cows, they inevitably caught cowpox, which was a less serious disease and often caught through exposure to infected cows.
Jenner speculated that the bout of cowpox made milkmaids immune to smallpox. He even encountered locals who claimed to have deliberately infected themselves with cowpox to immune themselves against smallpox. He was a forward-thinking doctor who liked to experiment and hence he decided to prove this theory. In 1796, he inserted pus taken from a milkmaid infected with cowpox into a cut made in the arm of a local boy, James Phipps. After the boy had caught and then recovered from cowpox, he exposed him to smallpox through an injection. The boy remained healthy and this is how the world’s first vaccine was produced. This technique provided safer and more reliable protection against smallpox than traditional inoculation.
The following year, he submitted a paper to the Royal Society in 1797. The Royal Society felt his ideas were too revolutionary and needed more proof. He proceeded and went on to vaccinate several more children, including his own 11-month-old son. Two years later, in 1798, the results were published. He called this new method ‘vaccination’ after the Latin word for cow (vacca). But he had no explanation for why this method was successful. Partly, because there were no microscopes in which viruses could be seen at that time.
The path ahead was not easy for Jenner; his apparent discovery was met with much opposition and even ridicule. Critics claimed that it was ungodly to inoculate a healthy human with material from an infected animal. But the obvious advantages of vaccination over inoculation and the protection it provided ultimately won out. Since the access to medical treatment was limited in the poor communities, it took several decades before the full benefits of the method were realised.