Answer:
It was groundbreaking.
Explanation: Edward Jenner, was an English scientists and physician he was the first to develop a vaccine as a means of preventive medicine for small pox,known to be one of the most deadly Diseases of the eigtheenth century. This discovery was a great and ground breaking achievement for Edward Jenner and the World. In recent times,Many scientists have been able to develop new vaccines that has helped to Prevent several Diseases like polio,measles,tetanus, hepatitis b etc.