Antigenic and EM characterization of the Chiron experimental hepatitis C virus vaccine

Shr-Hau Hung; Jonathan L Torres; Fang Chen; Erick Giang; Andrew B Ward; Mansun Law

doi:10.1016/j.vaccine.2025.127239

Antigenic and EM characterization of the Chiron experimental hepatitis C virus vaccine

Vaccine. 2025 Jun 11:58:127239. doi: 10.1016/j.vaccine.2025.127239. Epub 2025 May 16.

Authors

Shr-Hau Hung¹, Jonathan L Torres², Fang Chen¹, Erick Giang¹, Andrew B Ward², Mansun Law³

Affiliations

¹ Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA.
² Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
³ Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA. Electronic address: mlaw@scripps.edu.

PMID: 40381513
DOI: 10.1016/j.vaccine.2025.127239

Abstract

The Chiron experimental HCV vaccine, the only envelope-based HCV vaccine candidate to date, was immunogenic and safe in a phase 1 trial, though its efficacy remains untested. This study examined the antigenic properties of the vaccine antigens by immunoassays and EM, revealing inconsistent presentation of AR1/5 epitopes. The vaccine elicited mainly strain-specific neutralizing antibodies in humans and non-human primates, highlighting the need for rational antigen design to improve vaccine breadth.

Keywords: Antigenicity; Chiron HCV E1E2; Electron microscopy; HCV vaccine.

MeSH terms

Animals
Antibodies, Neutralizing / blood
Antibodies, Neutralizing / immunology
Epitopes / immunology
Hepacivirus* / immunology
Hepacivirus* / ultrastructure
Hepatitis C Antibodies / blood
Hepatitis C Antibodies / immunology
Hepatitis C* / immunology
Hepatitis C* / prevention & control
Humans
Viral Hepatitis Vaccines* / immunology

Substances

Viral Hepatitis Vaccines
Antibodies, Neutralizing
Hepatitis C Antibodies
Epitopes