This Smithsonian National Museum of American History exhibit celebrates the 50th anniversary of effective vaccines to prevent polio. On April 12, 1955, Dr. Jonas Salk, a virologist working at the University of Pittsburgh with funding from the March of Dimes, announced his vaccine against the disease. In 1957, trials of Dr. Albert Sabin's vaccine began. Between 1955 and 1957, the incidence of polio in the U.S dropped by 85 to 90 percent. Since it draws upon the vast collections of the Smithsonian, the exhibit is lavishly illustrated with historical photographs, and all kinds of ephemera, such as an advertisement for Drinker-Collins respirators, "Polio Pioneer" buttons given to children who participated in Salk vaccine clinical trials, and a March of Dimes bank. The exhibit provides background information on polio-related topics including the March of Dimes, established by Franklin D. Roosevelt in 1938, an organization that took in millions of small donations to support the care of people who contracted polio and research into prevention and treatment; the history of vaccines; and the differences between Salk's killed-virus vaccine, and Sabin's live-virus vaccine.