George Frederick Dick was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 physician

Physician

A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

 and bacteriologist best known for his work with scarlet fever

Scarlet fever

Scarlet fever is a disease caused by exotoxin released by Streptococcus pyogenes. Once a major cause of death, it is now effectively treated with antibiotics...

.

Dick studied scarlet fever

Scarlet fever

Scarlet fever is a disease caused by exotoxin released by Streptococcus pyogenes. Once a major cause of death, it is now effectively treated with antibiotics...

 whilst serving the Army Medical Corps

Army Medical Department (United States)

The Army Medical Department of the U.S. Army – known as the AMEDD – comprises the Army's six medical Special Branches of officers and medical enlisted soldiers. It was established as the "Army Hospital" in July 1775 to coordinate the medical care required by the Continental Army during the...

 during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. Dick continued with his research into scarlet fever following the war, and in 1923, in collaboration with his wife Gladys Rowena Dick, managed to locate the cause of the disease in a toxin

Toxin

A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...

 produced by a strain of Streptococcus

Streptococcus

Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...

 bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

. Using this, they were able to create a non-toxic vaccine for immunization.

He was a professor of clinical medicine at Rush Medical College

Rush Medical College

Rush Medical College is the medical school of Rush University, a private university in Chicago, Illinois. Rush Medical College was one of the first medical colleges in the state of Illinois and was chartered in 1837, two days before the city of Chicago was chartered, and opened with 22 students on...

, Chicago

Chicago

Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...

 (1918- 33), and then became the head of the department of medicine at the University of Chicago

University of Chicago

The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...

(1933 - 45).