Jenner, an English surgeon, discovered the smallpox vaccine and laid the foundations of modern immunology. Apprenticed to a surgeon at 13, Jenner then studied under John Hunter, a pioneer in morphology. Jenner found that people who had been sick with the relatively harmless disease cowpox did not contract smallpox. His invaluable experiments, beginning in 1796 with the vaccination of eight-year-old James Phipps, proved that cowpox provided immunity against smallpox. What killed Jenner in 1823? Discuss