A vaccine is a substance that is usually injected into a person or animal to protect against disease (Merriam-Webster Dictionary). Vaccines help protect children from multiple diseases; these diseases range from chickenpox to polio. Vaccines are essential for controlling disease and death. Vaccines help prevent diseases from becoming epidemics around the world by decreasing the amount of contagious diseases. In the year 1900, the number one disease causing death was influenza, also known as influenza. In 1918, influenza accounted for 5% of deaths worldwide (Kliff). Worldwide, influenza claimed between thirty and one hundred and fifty thousand lives in 1918. Now influenza causes approximately 0.0162% of deaths worldwide (Kliff). The flu vaccine was created between 1900 and the present day. The vaccine was invented in the 1930s but was perfected in the 1940s (Suddath). Since the 1930s the flu has declined to today causing only 16 deaths per 100,000 (Kliff). This is a perfect example of how with the use of vaccines the spread of a certain disease has slowly decreased. Another example of this life-saving tactic is the invention of the smallpox vaccine. Smallpox disease has always played an important role throughout history. Smallpox may have been one of the deadliest diseases throughout history. There have been many cases of smallpox which appears to have been decimated many times, but has returned and taken the lives of many. From the 1500s until President Lincoln in the year 1863 smallpox was a feared disease. Vaccines were created and helped immensely, but once the disease seemed to be under control, it would appear again,... half of the paper... The epidemic could be the worst in 50 years." Discovery News. (2013 ): Web page. November 21, 2013. "Whooping Cough." Henderson, dir. The College of Physicians of Philadelphia, 2008 November 2013. US Centers for Disease Control and Prevention .Web.U.S. Center for Disease Control and Prevention. Mumps 2009. Web.U.S. Center for Disease Control and Prevention US Disease Prevention. 2012. Web. US Center for Disease Control and Prevention. MedicineNet, 19 03 2012. Web 23 November 2013.