The name of the first successful vaccine is the smallpox vaccine. Developed by Edward Jenner in 1796, this vaccine provided immunity against the smallpox virus, a deadly disease that had claimed countless lives throughout history. Jenner used material from cowpox sores to create the vaccine, exploiting the cross-immunity between the two viruses. This groundbreaking work laid the foundation for modern vaccination practices and the development of vaccines for numerous diseases. As a result of widespread vaccination efforts, smallpox was declared eradicated in 1980, making it the first disease to be eliminated through vaccination.