Medical science has come a long way in the 20th and 21st centuries and a few of the most important innovations have paved the way for a future of medical discoveries. Smallpox alone killed more than 500,000,000 people. In the 18th century, nearly half a million people succumbed to the disease every year. The smallpox vaccine is just one of many medical discoveries that helped save millions of lives. Here are a few of history’s top discoveries. (click here to enlarge) Carrington College’s Online Health Care Administration Program