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

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.