The document discusses the history and development of the polio vaccine. It describes how the polio vaccine was created to prevent polio, a viral disease that causes paralysis. There are two main types of polio vaccines - the inactivated polio vaccine (IPV) developed by Jonas Salk, and the oral polio vaccine (OPV) developed by Albert Sabin. The IPV uses dead virus and is administered via injection, while the OPV uses live attenuated virus and is taken orally. Widespread use of polio vaccines has nearly eradicated the disease globally.