History of smallpox In the late 1770s, during the American Revolutionary War, smallpox returned once more and killed thousands. Peter Kalm in his "Travels in North America", described how in that period, the dying Indian villages became overrun with wolves feasting on the corpses and weakened survivors. Smallpox was also used as a weapon by the British. In 1799, the physician Valentine Seaman administered the first smallpox vaccine in the United States. He gave his children a smallpox vaccination using a serum acquired from Edward Jenner, the British physician who invented the vaccine from fluid taken from cowpox lesions. Though vaccines were misunderstood
Smallpox scar. The antibodies induced by vaccinia vaccine are cross-protective for other orthopoxviruses, such as monkeypox, cowpox, and variola (smallpox) viruses. Neutralizing antibodies are detectable 10 days after first-time vaccination, and seven days after revaccination. Historically, the vaccine has been effective in preventing smallpox infection in 95 percent of those vaccinated. Smallpox vaccination provides a high level of immunity for three to five years and decreasing immunity thereafter. If a person is vaccinated again later, immunity lasts even longer. Studies of smallpox cases in Europe in the 1950s and 1960s demonstrated that the fatality rate among persons vaccinated less than 10