Elimination of diseases happens when almost everyone in a given population is immunized. If the ratio of unimmunized people to immunized people is greater, there is a much higher chance of spreading the disease to the entire population. Statistics show that if everyone gets immunized the disease can be contained if one or two people were to have the disease in the population. But, if only some people are immunized the disease cannot be contained and will spread throughout the population. An example showing the importance of vaccines would be the polio epidemic in the 1950’s. Polio killed 3,000 americans and 58,000 cases were reported (Lerner). Jonas Salk created the first polio vaccine and did not succeed the first time it was distributed. But, in 1961, an oral polio vaccine developed by Albert B. Sabin and was licensed in the United States (Lerner). Sabin’s vaccine became successful and since then, there has not been one new case of polio in the United States since 1975, or in the Western Hemisphere since 1991 (Lerner). Without vaccines there would be constant epidemics of disease threatening populations around the world. What parents and other people are believing today is that vaccines are causing their children to develop autism and are now not choosing to vaccinate their children. Making the decision to say no could cause epidemics like the polio epidemic to occur again. Vaccines can have some type of side effects, but can autism really be