In the era of rapid mRNA-based vaccines: Why is there no effective hepatitis C virus vaccine yet?

Figure 1 Challenges in hepatitis C virus vaccine research. Graphical representation of all the hurdles yet to be overcome in order to develop effective vaccines against hepatitis C virus. Image created with BioRender.com. HCV: Hepatitis C virus. HVR1: Hypervariable region 1.

Figure 2 Summary of all hepatitis C virus vaccine approaches explored to date. The studies are divided in three categories depending on the highest stage of research achieved: In vitro evaluation only (in lilac background), pre-clinical studies in different animal models (in light blue background) and clinical trials in healthy volunteers and/or chronically hepatitis C virus-infected patients (in green background). For each approach (A to I) key characteristics on the vaccine candidates are provided. In addition, for all the technologies that have reached clinical trials, the ClinicalTrials.gov Identifier and the phase of the trial are indicated. Image created with BioRender.com.