Harvey James Alter (born September 12, 1935) is an American medical researcher, virologist, physician and Nobel Prize laureate, who is best known for his work that led to the discovery of the hepatitis C virus.

[1] Alter is the former chief of the infectious disease section and the associate director for research of the Department of Transfusion Medicine at the Warren Grant Magnuson Clinical Center in the National Institutes of Health (NIH) in Bethesda, Maryland.

This work eventually led to the discovery of the hepatitis C virus in 1988,[1] for which he shared the Nobel Prize in Physiology or Medicine in 2020 along with Michael Houghton and Charles M.

Later, Alter led a Clinical Center project to store blood samples used to uncover the causes and reduce the risk of transfusion-associated hepatitis.

Based on his work, the United States started blood and donor screening programs that lowered the cause of hepatitis due to this risk from 30 percent in 1970 to nearly 0.

[5] In 2005, he received the American College of Physicians Award for Outstanding Work in Science as Related to Medicine, and the First International Prize of Inserm (the French equivalent of NIH).

Alter was awarded the 2020 Nobel Prize in Physiology or Medicine alongside Michael Houghton and Charles M. Rice for "discoveries that led to the identification of [the] Hepatitis C virus.