Final answer:
Edward Jenner made significant contributions to epidemiology through his work on the development of the modern process of vaccination.
Step-by-step explanation:
Edward Jenner, an English physician, made significant contributions to epidemiology through his work on the development of the modern process of vaccination. Jenner observed that milkmaids who developed cowpox, a milder disease similar to smallpox, were immune to smallpox. This led him to hypothesize that exposure to a less virulent pathogen could provide immune protection against a more virulent pathogen, providing a safer alternative to variolation. Jenner tested his hypothesis by injecting infectious cowpox materials into a young boy, who later did not contract smallpox when exposed to it.