Two polio vaccines are used throughout the world to combat polio. The first was invented by Jonas Salk, and first tested in 1952 and announced to the world by Salk on March 26, 1953. It consists of an injected dose of killed polio virus. Albert Sabin[?] produced a cheaper and more effective oral polio vaccine in 1962.
... of the first book, De imitatione Christi
et contemptu omnium vanitatum mundi. It consists
of four books and seems to have been written in
meter and rime, a fact ...