Hepatitis C vaccine


A hepatitis C vaccine, a vaccine capable of protecting against hepatitis C, is not available. Although vaccines exist for hepatitis A and hepatitis B, development of a hepatitis C vaccine has presented challenges. No vaccine is currently available, but several vaccines are currently under development.
Most vaccines work through inducing an antibody response that targets the outer surfaces of viruses. However the Hepatitis C virus is highly variable among strains and rapidly mutating, making an effective vaccine very difficult.
Another strategy which is different from conventional vaccine is to induce the T cell arm of the immune response using viral vectors, adenoviral vectors that contain large parts of the hepatitis C virus genome itself, to induce a T cell immune response against hepatitis C. Most of the work to develop a T cell vaccine has been done against a particular genotype. There are six different genotypes which reflect differences in the structure of the virus. The first approved vaccine will likely only target genotypes 1a and 1b, which account for over 60% of chronic hepatitis C virus infections worldwide. Likely, vaccines following the first approved vaccine will address other genotypes by prevalence.
VLP based hepatitis C vaccines are also subject of intensive research.
Since 2014, well-tolerated and extremely effective direct‐acting antiviral agents have been available which allows eradication of the disease in 8–12 weeks in most patients. While this has changed treatment options drastically for patients with hepatitis C virus, it does not replace a vaccine that would prevent people from ever getting infected with the virus and will likely not be sufficient to eradicate the hepatitis C virus completely.

Specific vaccines

is developing a synthetic multi-antigen DNA vaccine covering hepatitis C virus genotypes 1a and 1b and targeting the HCV antigens nonstructural protein 3 and 4A, as well as NS4B and NS5A proteins. Following immunization, rhesus macaques mounted strong HCV-specific T cell immune responses strikingly similar to those reported in patients who have cleared the virus on their own. The responses included strong HCV antigen-specific interferon-γ, tumor necrosis factor-α, and interleukin-2 induction, robust CD4 and CD8 T cell proliferation, and induction of polyfunctional T cells. A Phase I clinical trial of the Inovio Pharmaceuticals vaccine is currently on-going