The Vaccine that Changed the World
Vaccines represent preventive medicine at its best. They are, at least in theory, available to everyone and remarkably effective in preventing or significantly attenuating infectious diseases, particularly viral infections. In the 21st century we have a wealth of vaccines available and, ironically, the luxury of choosing whether or not to get them. For those living prior to their development, becoming disabled or dying from a variety of infectious diseases was a common fate. Living into adulthood or even surviving childhood were not guaranteed. The idea and development of vaccines depended upon the ingenuity, persistence, and often sacrifices, of many individuals throughout history. In fact, although we date the development of the first vaccine, smallpox, to the late 18th century, the concept of exposing a person to a small amount of infected material from another person to prevent that disease, dates back to at least 200 BCE. I will review the history of the vaccine that may have saved more lives than any other: Smallpox.
Smallpox remains the only human disease to have been eradicated. According to the WHO, "Many believe this achievement to be the most significant milestone in global public health".
The smallpox virus, or variola, is known to have afflicted humans for thousands of years. Evidence has been extracted from ancient art and lore as well as studies of preserved human tissue, as in Egyptian mummies from 1350 BCE. Over these millennia, smallpox took the lives of millions of people. It killed at least 1 of every 3 infected individuals. The symptoms were horrible, including high fevers, vomiting, painful mouth sores and fluid-filled sores all over the body. It could result in death within two weeks. Survivors were often left blind and infertile. There was no cure and outbreaks occurred repeatedly the world over.
One wonders if this was the basis for the 6th "plague" visited upon the Egyptians as described in the Bible: "Then the Lord said to Moses and Aaron, 'Take handfuls of soot from a furnace and have Moses toss it into the air in the presence of Pharoah. It will become fine dust over the whole land of Egypt, and festering boils will break out on men and animals throughout the land'." Exodus 9:8-9. (This is a historical, not religious, observation).
The practice of transferring small amounts of material taken from smallpox sores to the uninfected, known as "variolation", occurred as early as 200 BCE. How remarkable that this idea was conceived nearly 2000 years prior to the discovery of bacteria and viruses, not to mention the immune system! A form of variolation used in China known as "insufflation" was described in writings from the mid 1500's. In this process, scabs from smallpox sores were "dried, ground and blown into the nostrils using a pipe." Accounts from India suggest the use of a needle to transfer infected fluid from sores to the skin of healthy children even before this. In 1721 Lady Mary Wortley Monagu, the wife of a British ambassador to Turkey, brought the idea of inoculation/variolation to Europe after seeing it practiced in the Ottoman Empire. She had her 2 daughters inoculated with apparent success. Ironically, it had also been brought to the attention of Cotton Mather, an American , in 1716, when he learned about it from his African slave, Onesimus. It had apparently long been used in West Africa. Mather tried unsuccessfully to get it used during an outbreak of smallpox in Massachusetts in 1721.
In 1774 Benjamin Jesty, an English farmer put into action his belief that infection with cowpox, a human and bovine disease, could prevent smallpox infection. He even intentionally gave the cowpox infection to individuals to prevent smallpox. He has not been given credit as his information was not publicized even though it was known in farming communities in the late 18th century. It was not until 1796 that we hear anything further. In that year, a British physician, Edward Jennings made a similar logical leap after observing that "milk maids" who developed the related but much milder disease of "cowpox" seemed to have developed protection from smallpox.
Dr. Jenner, using material from a cowpox sore, inoculated an 8 year old boy, who then felt ill for a few days followed by full recovery. Two months later Jennings inoculated the same boy with material from a smallpox sore. The boy did not develop smallpox thus proving that the cowpox infection provided protection from smallpox. Thus the use of the term "vaccine", from the Latin word for cow. Again, an ingenious life-saving intervention long before the details of the human immune system had been discovered!
By 1801 this vaccine had proven repeatedly effective and its use then spread to other continents. In Dr. Jenner's time smallpox was killing 10% of the world's population, as high as 20% in more populous cities. Jenner is considered the "Father of Immunology" and is believed to have prevented more deaths than any person in history.
In 1806, both Napoleon Bonaparte and President Thomas Jefferson endorsed the vaccine. By 1900 smallpox had been eliminated throughout much of Europe but continued to take the lives of over 2 million people per year worldwide. It was another 50 years until the production of vaccine that could be stored without refrigeration and therefore transported safely. The WHO set the goal of worldwide eradication of smallpox in 1958. This was undertaken by the cooperation and unified commitment of scientists, public health and world leaders working toward a common goal. There was unprecedented joint research shared between the U.S. and the Soviet Union. In 1980 the World Health Organization declared smallpox officially eradicated. This was accomplished via prevention as there was no known cure. After millenia of suffering and death, there has not been a single recorded case for almost 50 years.
When there is universal commitment to a common objective, great things are possible. Such an aspiration outweighs political, religious, racial and economic interests, highlighting the best that humans can accomplish.
References:
-CDC. Smallpox. Available at https://www.cdc.gov/smallpox/index.html
-WHO. Smallpox. Available at https://www.who.int/health-topics/smallpox
