Hilary Koprowski (5 December 1916 – 11 April 2013) was a Polish virologist and immunologist active in the United States who demonstrated the world's first effective live polio vaccine.

Hilary went to Rome, where he spent a year studying piano at the Santa Cecilia Conservatory; while Irena went to France, where she gave birth to their first child, Claude Koprowski, and worked as an attending physician at a psychiatric hospital.

After World War II the Koprowskis settled in Pearl River, New York, where Hilary was hired as a researcher for Lederle Laboratories, the pharmaceutical division of American Cyanamid.

[12] He and his wife are buried at West Laurel Hill Cemetery, Southlawn Section, Lot 782, Bala Cynwyd, Pennsylvania.

[10] He administered the vaccine to himself in January 1948 and, on 27 February 1950, to 20 children at Letchworth Village, a home for disabled persons in Rockland County, New York.

Koprowski received many honorary degrees, academic honors, and national decorations, including the Order of the Lion from the King of Belgium, the French Order of Merit for Research and Invention, a Fulbright Scholarship, and appointment as Alexander von Humboldt Professor at the Max Planck Institute for Biochemistry in Munich.

In 1989 he received the San Marino Award for Medicine and the Nicolaus Copernicus Medal of the Polish Academy of Sciences in Warsaw.

On 25 February 2000 Koprowski was honored with a reception at Philadelphia's Thomas Jefferson University celebrating the 50th anniversary of the first administration of his oral polio vaccine.

British journalist Edward Hooper publicized a hypothesis that Koprowski's research into a polio vaccine in the Belgian Congo in the late 1950s might have caused AIDS.

[1] The journal Science refuted Hooper's claims, writing: "[I]t can be stated with almost complete certainty that the large polio vaccine trial... was not the origin of AIDS.

In a separate court case, he won a regretful clarification,[21] and a symbolic award of $1 in damages,[22] in a defamation suit against Rolling Stone, which had published an article repeating similar false allegations.

[23] A concurrent defamation lawsuit that Koprowski brought against the Associated Press was settled several years later; the settlement's terms were not publicly disclosed.

[22] Koprowski's original reports from 1960 to 1961 detailing part of his vaccination campaign in the Belgian Congo are available online from the World Health Organization.