Immunization can not only stop epidemics in their tracks; they can also prevent future disease outbreaks.
Smallpox is a disease thought to have originated around 10,000 B.C. in the first human agricultural settlements in Africa. The earliest evidence of the disease was found on ancient Egyptian mummies dating as far back as the 16th century B.C. Smallpox produced waves of epidemics over the centuries, claiming millions of lives.
Before the discovery of a vaccine, inoculation for smallpox took the form of variolation, performed with "a lancet wet with fresh matter taken from a ripe pustule of some person who suffered from smallpox," according to an article published by the U.S. National Library of Medicine.
In the late 18th century, an English doctor named Edward Jenner created the world's first vaccine, when he observed that those who had been infected with cowpox had immunity from smallpox. Jenner first tried out his hypothesis by infecting an eight-year-old boy with cowpox and then exposing him to smallpox, a move as ethically questionable today as it was in 1796. In that trial and others that followed, Jenner proved his vaccine effective.
Just as Jenner created the first vaccine, so too did he face the world's first anti-vaccination movement. Anti-vaccination advocates pointed not to the work Jenner did in creating the vaccine, but rather a disputed study he conducted nearly 10 years earlier on the cuckoo bird in an attempt to discredit him. Thankfully, the horrors of smallpox far outweighed the cuckoo concerns of the anti-vaccination movement. Within 200 years of Jenner's discovery, the WHO declared smallpox eradicated, the first infectious disease in history to receive such a designation.
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