Hepatitis C Virus Vaccine: Challenges and Prospects

Abstract

The hepatitis C virus (HCV) causes both acute and chronic infection and continues to be a global problem despite advances in antiviral therapeutics. Current treatments fail to prevent reinfection and remain expensive, limiting their use to developed countries, and the asymptomatic nature of acute infection can result in individuals not receiving treatment and unknowingly spreading HCV. A prophylactic vaccine is therefore needed to control this virus. Thirty years since the discovery of HCV, there have been major gains in understanding the molecular biology and elucidating the immunological mechanisms that underpin spontaneous viral clearance, aiding rational vaccine design. This review discusses the challenges facing HCV vaccine design and the most recent and promising candidates being investigated.

Keywords: animal models; hepatitis C virus; immune responses; neutralising antibodies; vaccines.

Figure 1

(A) Schematic diagrams of the hepatitis C virus envelope glycoproteins E1 and E2, showing N-linked glycosylation sites (N), transmembrane domains (TMDs), and the E1 fusion peptide (FP). E2 hypervariable regions (HVRs) 1 and 2, and the intergentypic variable region (IgVR) are also depicted. Linear epitopes I, II and III are highlighted in red, dark blue and light blue, respectively. (B) E2 structure (PDB: 6MEH). Linear epitopes I, II and III are highlighted in the corresponding schematic. Antigenic regions (ARs) are also shown.