One of the most deadly diseases throughout the course of human history is Smallpox. It’s estimated it was responsible for 300-500 million deaths during the 20th century. In 1796 Dr. Edward Jenner discovered it was possible to immunize a person by injecting him with a weakened form of a virus from the same family as Smallpox. This led to worldwide vaccination campaigns that resulted in the eradication of the disease. The lesson is sometimes something bad, such as a small form of a virus can lead to something good. We have all experienced this principle at in our lives. A ...