It all started with compox

No discussion of vaccines can be considered complete without a discussion of smallpox and Edward Jenner, a country doctor in England who is credited with performing the world's first vaccination in 1796.[5] The eradication of smallpox is probably the world's greatest success story. For thousands of years, epidemics swept across continents, decimating populations and at times changing the course or history.

The Crusaders brought smallpox back with them from the Holy Land. The Conquistadors carried it to the New World. This disease destroyed the Incan and Aztec empires. In the American colonies, smallpox helped decimate the indigenous peoples, including Pocahontas who died of smallpox in 1617 after visiting London. Rich and poor, famous and unknown, smallpox did not discriminate. Queen Mary II of England, Emperor Joseph I of Austria, King Luis I of Spain, Tsar Peter II of Russia, and King Louis XV of France are a few of the heads of state who died from smallpox.

The disease, for which no effective treatment was ever developed, killed as many as 30 percent of those infected. Between 65 percent and 80 percent of survivors were marked with deep-pitted scars (pockmarks), most prominent on the face. George Washington, for example, survived a bout with smallpox but was severely scarred.

Long before the causes of this disease were known and understood, many tried to protect the population from this disfiguring and deadly disease. The Chinese may have begun intentionally infecting themselves with smallpox virus as early as the 10th century, trying to prevent the disease by exposing uninfected individuals to the pus and fluid from a smallpox lesion. The thinking was that the dried pus would confer protection to the individual. This practice, called variolation, was also used hundreds of years later in other parts of the world. Specifically, in the early 18th century, Lady Mary Wortley Montagu, the wife of the British ambassador to Constantinople, who as a young girl contracted smallpox and whose brother died of the disease, popularized variolation upon her return to England. Because of Lady Montagu's efforts, the Princess of Wales in 1722 was persuaded to have her two children inoculated against smallpox.

Although the physiological effects of variolation varied, ranging from a mild illness to death, its effectiveness was evident. Smallpox mortality and morbidity rates were lower in populations that used variolation than in those that did not.[6]

{embed="ref/stat-menu-disease-prevention-vaccination"}

Across the Atlantic Ocean, smallpox was threatening Boston. Clergyman Cotton Mather and Dr. Zabdiel Boylston in Massachusetts practiced variolation in an attempt to inoculate residents of this city. Although inoculations were illegal in the American colonies, their efforts helped prevent a wide-scale smallpox epidemic.

They documented that the smallpox case fatality rate was much lower among those inoculated than those not inoculated.[6]