To Include or Occlude: Rational Engineering of HCV Vaccines for Humoral Immunity.

Direct-acting antiviral agents have proven highly effective at treating existing hepatitis C infections but despite their availability most countries will not reach the World Health Organization targets for elimination of HCV by 2030. A prophylactic vaccine remains a high priority. Whilst early vaccines focused largely on generating T cell immunity, attention is now aimed at vaccines that generate humoral immunity, either alone or in combination with T cell-based vaccines. High-resolution structures of hepatitis C viral glycoproteins and their interaction with monoclonal antibodies isolated from both cleared and chronically infected people, together with advances in vaccine technologies, provide new avenues for vaccine development.

Hepatitis B Virus (HBV) Subviral Particles as Protective Vaccines and Vaccine Platforms.

: Hepatitis B remains one of the major global health problems more than 40 years after the identification of human hepatitis B virus (HBV) as the causative agent. A critical turning point in combating this virus was the development of a preventative vaccine composed of the HBV surface (envelope) protein (HBsAg) to reduce the risk of new infections. The isolation of HBsAg sub-viral particles (SVPs) from the blood of asymptomatic HBV carriers as antigens for the first-generation vaccines, followed by the development of recombinant HBsAg SVPs produced in yeast as the antigenic components of the second-generation vaccines, represent landmark advancements in biotechnology and medicine. The ability of the HBsAg SVPs to accept and present foreign antigenic sequences provides the basis of a chimeric particulate delivery platform, and resulted in the development of a vaccine against malaria (RTS,S/AS01, MosquirixTM), and various preclinical vaccine candidates to overcome infectious diseases for which there are no effective vaccines. Biomedical modifications of the HBsAg subunits allowed the identification of strategies to enhance the HBsAg SVP immunogenicity to build potent vaccines for preventative and possibly therapeutic applications. The review provides an overview of the formation and assembly of the HBsAg SVPs and highlights the utilization of the particles in key effective vaccines.

[Vaccination against hepatitis B virus]. / La vaccination contre le virus de l'hépatite B.

More than 200 million people infected with hepatitis B virus worldwide, with high risk of developing hepatic disease ranging from chronic hepatitis to hepatocellular carcinoma, underline an imperative need for an efficacious vaccine. Many studies have provided repeated assurance on the safety and efficacy of hepatitis B vaccines derived from plasma pooled from carriers. However, alternative methods for vaccine production are necessary and DNA recombinant vaccines are currently available. Recombinant hepatitis B vaccines are safe, antigenic, and free from side effects. The immunogenicity of yeast hepatitis B vaccine is similar to that of the plasma-derived vaccine. In the mammalian recombinant vaccine, pre-S2 region is added to S region and should confer quicker and stronger efficacy in hepatitis B protection.