Discovery of the hepatitis C virus

Area of Science:

• Virology
• Molecular Biology
• Hepatology

Background:

• Parenterally transmitted non-A, non-B viral hepatitis (NANBH) posed a significant public health challenge.
• The viral etiology of NANBH remained elusive despite extensive research.

Observation:

• A novel flavi-like virus, later termed hepatitis C virus (HCV), was identified through molecular biological methods.
• A specific cDNA clone (5-1-1) was isolated from infected chimpanzee samples using a novel immunoscreening technique.

Findings:

• The isolated clone hybridized to a large single-stranded RNA molecule, confirming its viral origin and distant sequence identity to flaviviruses.
• HCV clone 5-1-1 encoded an antigen that elicited antibody seroconversion in infected chimpanzees and humans.
• HCV was identified as the primary cause of parenterally transmitted NANBH, affecting an estimated 170 million people globally.

Implications:

• Development of blood screening tests for HCV antibodies and RNA effectively reduced transfusion-associated NANBH.
• Targeting viral-encoded enzymes is a key strategy in ongoing drug development for HCV.
• The chimpanzee model proved crucial for demonstrating the feasibility of HCV vaccination strategies.