A century of documented failures of smallpox vaccination
In 1796, Edward Jenner tested a popular belief: that cowpox protected against smallpox. He obtained cowpox material from a milkmaid and used it to inoculate an eight-year-old boy named James Phipps, whom he then deliberately exposed to smallpox. Because the boy did not fall ill, Jenner concluded that the procedure—cowpoxing, later given the more scientific-sounding
