Recent Advances in Clinical Trials of HCV Vaccines

Abstract

  Hepatitis C virus infects nearly 3% of the global population, and spreads to 3-4 million new people annually. HCV infection is a leading cause of liver cirrhosis, hepatocellular carcinoma, and end-stage liver diseases and causes liver-related death in more than 300,000 people each year. Unfortunately, there is currently no vaccine for HCV prevention (prophylactic vaccine) or treatment (therapeutic vaccine). Circulating HCV is genetically diverse, and therefore a broadly effective vaccine must target conserved T- and B-cell epitopes of the virus and induce strong cross-reactive CD4+/CD8+ T-cell and neutralizing antibody responses in preventing or clearing HCV infection. So far, a few of vaccine development approaches are successful and some of the HCV vaccine candidates have reached human clinical trials, including those modalities mainly based on recombinant proteins (envelope proteins and core protein subunit), synthetic peptides, DNA (plasmid) and viral vectors (virosome). Encouraging results were obtained for those HCV vaccine formulations consisting of prime-boost regimen involving a live recombinant viral vector vaccine alone or in combination with DNA or subunit vaccine. Among several other vaccine strategies under preclinical development, the most promising one is virus like particle based vaccine that will be moving into human studies soon.