This item is a 4" X 6 1/2", first day cover postmarked January 15, 1957-Washington D.C. commemorating Dr. Jonas Salk.A first day of issue cover or first day cover (FDC) is a postage stamp on a cover, postal card or stamped envelope franked on the first day the issue is authorized for use within the country or territory of the stamp-issuing authority. Sometimes the issue is made from a temporary or permanent foreign or overseas office. There will usually be a first day of issue postmark, frequently a pictorial cancellation, indicating the city and date where the item was first issued, and "first day of issue" is often used to refer to this postmark. Depending on the policy of the nation issuing the stamp, official first day postmarks may sometimes be applied to covers weeks or months after the date indicated.Postal authorities may hold a first day ceremony to generate publicity for the new issue, with postal officials revealing the stamp, and with connected persons in attendance, such as descendants of the person being honored by the stamp. The ceremony may also be held in a location that has a special connection with the stamp's subject, such as the birthplace of a social movement, or at a stamp show......Jonas Salk became a medical hero in 1955 for developing a vaccine that helped conquer polio. Salk grew up in New York City and earned a medical degree in 1939 from New York University. He then worked at the University of Michigan and the University of Pittsburgh, studying influenza and, during World War II, working on a flu vaccine for the U.S. Army. He began work on the problem of polio (at the time known as "infantile paralysis") in 1947, thanks in large part to the work of a Harvard group led by John Enders. (Enders had developed a way to grow the polio virus, which in turn allowed expanded research.) Many microbiologists were working on a vaccine, but Salk got there first. He began a program of experimental vaccines on humans in 1952, and by 1954 the vaccine was being prepared in quantity. The story became public in 1955 and Salk became a celebrity because of the success of the vaccine. A tireless champion of public health education and vaccinations, Salk became the director of the Salk Institute for Biological Studies in 1963, a post he held the rest of his career. He also authored several books, including Man Unfolding (1972), The Survival of the Wisest (1973) and Anatomy of Reality (1983).A hand signed cut signature by Jonas Salk with a fountain pen in black has been affixed to the front of the first day cover. The cut signature portion is approximately 1 1/2" X 2 1/2"............BOTH FIRST DAY COVER AND AUTOGRAPH ARE IN VERY GOOD CONDITION.