Edward Jenner — English Scientist born on May 17, 1749, died on January 26, 1823

Edward Jenner, FRS was an English physician and scientist who was the pioneer of smallpox vaccine, the world's first vaccine. He is often called "the father of immunology", and his work is said to have "saved more lives than the work of any other human"... (wikipedia)

I shall endeavour still further to prosecute this inquiry, an inquiry I trust not merely speculative, but of sufficient moment to inspire the pleasing hope of its becoming essentially beneficial to mankind.
I hope that some day the practice of producing cowpox in human beings will spread over the world - when that day comes, there will be no more smallpox.
The deviation of man from the state in which he was originally placed by nature seems to have proved to him a prolific source of diseases.