Smallpox Vaccine

Smallpox: The beginning of vaccines, the end of a disease.

Throughout history, there has never been anything small about smallpox, except perhaps the variola virus that causes it. A very old, deadly, and virulent disease, smallpox was often portrayed as the Grim Reaper himself. It occurred in two forms: variola major, which killed 20% or more of its victims, and variola minor, which killed 1%. (1) In its typically widespread epidemics, one percent was often rendered in the thousands.  Smallpox began somewhat like the flu, with chills, high fever, nausea, and aches. Within a few days, however, its characteristic rash of unsightly, painfully swollen pustules declared itself. The disease spread with devastating ease from one individual to another by way of droplets from the nose and mouth (for example, in sneezing), contact with the dried scabs of the pustules, or even contact with clothing or articles used by people with smallpox. It took about 12 days from exposure to the time the disease became evident; consequently, care givers of people with smallpox often caught the disease and then followed the first wave of victims to the grave within a matter of weeks

The numbers of people killed by smallpox in previous centuries are so large that they are numbing. Some authors credit smallpox with the collapse of both the Aztec and Incan empires, (2) civilizations that had prospered for centuries in South America, Mexico, and nearly halfway into the North American continent.  Some historians think smallpox emerged when humans first began to grow their own food, around 12,000 years ago. ⁽³⁾ From that time forward, every human era was marked by the presence of smallpox. Anthropologists have determined that eruptions evident on the skin of an Egyptian mummy of the 20th dynasty (1200-1100 B.C.) originated in smallpox. (4) From the earliest days of Europe, epidemics hung like a perpetual thundercloud over human society. As Thomas Babington Macaulay, a 19th-century British historian and statesman, (5) observed, "The havoc of the [bubonic, or "black"] plague had been far more rapid: but plague had visited our shores only once or twice within living memory; and the smallpox was always present...."(6) In 1519, the Spanish brought the disease to Mexico, where three and a half million Indians died. (7) In the 17th and 18th century, entire tribes in North America were wiped out by smallpox. (8) In the North American colonies, those who could, would flee to the countryside when the first case in a new epidemic appeared. (9) Epidemics often followed the course of a river or trails taken by traders and explorers. Many people who survived this highly contagious disease bore its mark forever in unsightly scars, and many were left blind. However, survivors truly triumphed, because having the disease and surviving it made them immune to having it again. Recognizing a similar, crossover effect in milkmaids who contracted cowpox--they appeared to be immune to smallpox--Dr. Edward Jenner began late 17th- and early 18th-century efforts to rid humanity of this scourge.

On May 14, 1796, Dr. Jenner performed an experiment that demonstrates how desperate people were to find some way to prevent this terrible scourge. He inoculated (vaccinated) a boy with matter taken from pustular cowpox lesions. Several weeks later, he challenged the success of the first inoculation by vaccinating the boy with smallpox. It was a tremendous risk, but it worked. The boy didn't develop smallpox. . Following publication of the results in June 1798, Jenner predicted the eventual eradication of smallpox. It took more than two centuries to prove him correct.

Jenner was hardly the first to observe that inoculation could prevent disease. Folk methods had been tried in many cultures, most of them relying herbs, magic, religious objects, prayers, incantations, and ultimately, luck. In some countries where more than one God was worshiped, there were gods to whom one prayed specifically for protection against smallpox. ⁽¹¹⁾ Medical practitioners in a number of ancient cultures had made observations about resistance to smallpox and had experimented with methods of immunization. Around 1700, nearly a century before Dr. Jenner's experiment, the practice of variolation--inoculation of a healthy person with pus from an infected person's smallpox lesions--was first tried in England, but the practice is believed to have originated in Africa and was learned from slaves. (12) In 1716, Cotton Mather, a member of the clergy, author, scholar, and physician in Boston, (13) sent Dr. John Woodward, an English physician, a vivid description of inoculation, as it had been described to him by one of his slaves, Anesimus. (14) The difference between the African method and Jenner's method was that Jenner involved a third party (cows) and a milder form of the disease (cowpox). His work opened the door to immunization as we know it today.

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Why we don't need smallpox vaccinations today?

Through massive vaccination efforts, smallpox has been wiped out. This historic victory occurred in this century, in the lifetimes of today's grandparents, parents, and children.

The one weakness of the variola (smallpox) virus is that it survives by being passed from one person to another. Public health officials worldwide joined together in the 1970s to take advantage of this weakness. They undertook to interrupt the cycle of smallpox through an intensive immunization and monitoring effort. In effect, by immunizing humans, they were removing the human incubator from the cycle, one vaccination at a time.

This was a huge task, involving many densely populated countries with limited health, technology, and communications facilities. Nevertheless, the effort succeeded. The last case of variola major occurred on Bhola Island in Bangladesh in October, 1975. The last case of variola minor was in Ethiopia in August, 1976. Although smallpox had been a nearly constant companion for twelve millennia, no one grieved over its quiet departure.

Because smallpox has been eradicated, smallpox vaccination has ceased everywhere. Travelers no longer need certificates to prove vaccination against this disease. (15) The children born at the end of this century may be puzzled by the small, round scars on their parents' and grandparents' upper left arms, the last scars left by smallpox.

This information was taken from the Centers of Disease Control and Prevention website (www.bt.cdc.gov).

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