Pressure-Inactivated Virus: A Promising Alternative for Vaccine Production

In recent years, many applications in diverse scientific fields with various purposes have examined pressure as a thermodynamic parameter. Pressure studies on viruses have direct biotechnological applications. Currently, most studies that involve viral inactivation by HHP are found in the area of food engineering and focus on the inactivation of foodborne viruses. Nevertheless, studies of viral inactivation for other purposes have also been conducted. HHP has been shown to be efficient in the inactivation of many viruses of clinical importance and the use of HHP approach has been proposed for the development of animal and human vaccines. Several studies have demonstrated that pressure can result in virus inactivation while preserving immunogenic properties. Viruses contain several components that can be susceptible to the effects of pressure. HHP has been a valuable tool for assessing viral structure function relationships because the viral structure is highly dependent on protein-protein interactions. In the case of small icosahedral viruses, incremental increases in pressure produce a progressive decrease in the folding structure when moving from assembled capsids to ribonucleoprotein intermediates (in RNA viruses), free dissociated units (dimers and/or monomers) and denatured monomers. High pressure inactivates enveloped viruses by trapping their particles in a fusion-like intermediate state. The fusogenic state, which is characterized by a smaller viral volume, is the final conformation promoted by HHP, in contrast with the metastable native state, which is characterized by a larger volume. The combined effects of high pressure with other factors, such as low or subzero temperature, pH and agents in sub-denaturing conditions (urea), have been a formidable tool in the assessment of the component's structure, as well as pathogen inactivation. HHP is a technology for the production of inactivated vaccines that are free of chemicals, safe and capable of inducing strong humoral and cellular immune responses. Here we present a current overview about the pressure-induced viral inactivation and the production of inactivated viral vaccines.