香蕉视频

A powder made from the scabs of pustules on the skin of people who had survived smallpox. The eradication of this horrific disease, which is thought to have first appeared around 10,000 B.C., is one of the greatest triumphs of medicine. The last recorded case of smallpox occurred in Somalia in 1977 and the world hasn鈥檛 seen a single case since. How did this triumph come about? Simple. Vaccination!聽

The name associated with the introduction of the smallpox vaccine is Dr. Edward Jenner, an English country physician who acted on the observation that milk maids who had come down with a disease known as cowpox never contracted smallpox. Jenner injected young James Phipps with material taken from a milkmaid鈥檚 cowpox pustule and then exposed him to smallpox. Obviously there were no ethics committees at the time to approve research. The boy didn鈥檛 get the disease and the era of vaccination, the term deriving from the Latin for cow, was on its way. Although Jenner usually gets the credit for introducing the smallpox vaccine, twenty years earlier Benjamin Jesty, a farmer, inoculated his wife with the cowpox virus and showed that it protected her from the disease. Unfortunately he didn鈥檛 have enough oomph to influence the medical community. Even more amazing is that a technique known as variolation had been introduced by a Chinese monk almost two thousand years earlier. After the death of the son of a high ranking Chinese official, the monk sought a way to cure the scourge of smallpox. He hit upon the idea of blowing the dust made from ground up pustules taken from the skin of smallpox victims up the nose of healthy people. In all likelihood this was generated by the observation that people who had survived smallpox became immune to the disease.聽

Lady Wortley Montague learned of this technique when her husband had a political posting in Turkey. She brought it to the attention of the British royal family and suggested that the variolation could be tested on condemned prisoners. Indeed four such men were treated and months later were exposed to smallpox, and all four survived. This was enough to convince the royals and the family underwent variolation. The French thought the English were crazy. In fact Voltaire opined that 鈥渢he English are fools, they give their children smallpox to prevent their catching it.鈥� They weren鈥檛 fools. In smallpox survivors the virus becomes weakened and can offer protection to others with only a small risk of causing the actual disease. The death rate from smallpox was usually somewhere between twenty and forty percent, but the death rate from variolation was only about one percent. It is interesting to note that this ancient technique saved many from contracting smallpox long before it was replaced by Jenner鈥檚 more effective vaccination.