Ever closer to a prophylactic vaccine for HCV

Abstract

Introduction: With 3 – 4 million new infections occurring annually, hepatitis C virus (HCV) is a major global health problem. There is increasing evidence to suggest that HCV will be highly amenable to a vaccine approach, and despite advances in treatment, a vaccine remains the most cost-effective and realistic means to significantly reduce the worldwide mortality and morbidity associated with persistent HCV infection.

Areas covered: In this review we discuss immune responses to HCV during natural infection, and describe how they may inform vaccine design. We introduce the current candidate vaccines for HCV and compare how these fare against the expected requirements of an effective prophylactic HCV vaccine in relation to the breadth, functionality, magnitude and phenotype of the vaccine-induced immune response.

Expert opinion: Although the correlates of immune protection against HCV are not completely defined, we now have vaccine technologies capable of inducing HCV-specific adaptive immune responses to an order of magnitude that are associated with protection during natural infection. The challenge next is to i) establish well-characterised cohorts of people at risk of HCV infection for vaccine efficacy testing and ii) to better understand the correlates of protection in natural history studies. If these can be achieved, a vaccine against HCV appears a realistic goal.

Keywords::

• functionality
• hepatitis C virus
• immunity
• phenotype
• prophylactic
• T cells
• vaccines
• viral vectors

Declaration of interest

E Barnes is funded by the Medical Research Council (MRC) UK, the Oxford NIHR Biomedical Research Centre and the James Martin School. Leo Swadling is funded by the MRC UK and Paul Klenerman is funded by the MRC UK, the Oxford NIHR Biomedical Research Centre and the James Martin School. The authors are currently working on Phase I HCV vaccine studies using adenoviral and MVA vectors in collaboration with an industrial partner Okairos. The authors have no other relevant affiliations or financial involvement with any organisation or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilised in the production of this manuscript.

Notes

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