Polymer-based nanoadjuvants for hepatitis C vaccine: The perspectives of immunologists

The hepatitis C virus (HCV) is an infection that affects the liver tissues in humans, leading to the development of effective prophylactic and therapeutic HCV vaccines to prevent a global epidemic. Scientists consider it challenging to produce a therapeutic vaccine for the treatment of hepatocellular carcinoma as opposed to a preventative vaccine. However, several drawbacks are involved with a peptide vaccine, including the low immunogenicity of the protein, significant instability, difficulty in delivery, and inefficient presentation of the antigens. Therefore, the investigation of adjuvants (i.e., immunomodulators) to enhance the efficacy of the vaccine is essential. Nanoparticles could potentially serve as vaccine delivery vehicles, acting as adjuvants for the effective transfer of antigens. The safety and effectiveness of nanoparticles and liposomes in modern vaccinology have also been confirmed. Biodegradable nanopolymers such as polyesters, polylactic acid and the copolymers, polyorthoesters, polyanhydrides, and polycarbonates are commonly used owing to their proper qualities in the combination or loading for the prevention of the degradation of the delivered antigens. The present study is specifically focused on the polymer-based nanoparticles that are mostly comprised a poly (amino acid) based copolymer and poly (D, L-lactic-co-glycolide), which could act as adjuvants or potential immunomodulators for the systems providing effective HCV vaccine delivery.