Virus-like particles as a highly efficient vaccine platform: diversity of targets and production systems and advances in clinical development

Abstract

Virus-like particles (VLPs) are a class of subunit vaccines that differentiate themselves from soluble recombinant antigens by stronger protective immunogenicity associated with the VLP structure. Like parental viruses, VLPs can be either non-enveloped or enveloped, and they can form following expression of one or several viral structural proteins in a recombinant heterologous system. Depending on the complexity of the VLP, it can be produced in either a prokaryotic or eukaryotic expression system using target-encoding recombinant vectors, or in some cases can be assembled in cell-free conditions. To date, a wide variety of VLP-based candidate vaccines targeting various viral, bacterial, parasitic and fungal pathogens, as well as non-infectious diseases, have been produced in different expression systems. Some VLPs have entered clinical development and a few have been licensed and commercialized. This article reviews VLP-based vaccines produced in different systems, their immunogenicity in animal models and their status in clinical development.

Fig. 1

Schematic diagram of non-enveloped VLP production. (A) VLP composed of a pathogen component. (B) Chimeric VLP composed of a pathogen component carrier fused to a vaccine target antigen.

Fig. 2

Schematic diagram of enveloped VLP production.