Virus-Like Particles (VLPs) is a combination of mono or multiple viral capsid protein subunit(s) with complete stereo structures, which can be produced by recombinant protein expression systems. VLPs can be modified and optimized through genetic engineering technology, and applied to various fields of bio-pharmaceutical industry, including new vaccines, drug delivery systems and tumor immunotherapy.

VLPs has significant advantages in terms of immunogenicity when designing new vaccine antigens. 1) Firstly, unlike subunit vaccines, VLPs is able to maintain the complete spatial structure of the nature virus. Additionally, they can also bind or couple with heterogenous polypeptide antigens, which is able to stimulate the pathogen-associated molecular patterns (PAMP) by antigen epitopes densely distributed on the particle surface, and induce strong humoral immunity and Th2 cell immunity via APC cells like DC to activate MHC II pathway. 2) Secondly, VLPs is able to enter the MHC I pathway through cross-presentation. This can active Th1 cell immunity, including CTL. 3) Lastly, through reasonable molecular design and process control, VLPs is able to flexibly adjust the expressed host nucleic acid residuals. This allows for the adjustment of the adjuvant effect of the host nucleic acid to match the specific antigen needs of different prophylactic vaccines and therapeutic immunity.

In terms of manufacturing process, VLPs also has significant advantages on cost and safety. It is generally produced by microbial systems such as yeast or Escherichia coli, eliminating the need for live virus culturing. Hence, this greatly reduces the risk of contamination of pathogenic microorganisms or live virus leakage. Besides, the quality control system of VLPs products is relatively mature.   

Bovax technical team has extensive experiences in VLPs design, modification, production, and characterization. Utilizing the genetic engineering and synthetic biology technologies of the recombinant expression systems, such as Pichia pastoris, Hansenula polymorpha and Escherichia coli, the team has developed a variety of VLPs vaccine and virus carrier vaccine pipelines, including recombinant humanpapilloma virus (HPV) vaccine, recombinant enterovirus vaccine, recombinant COVID-19 vaccine and recombinant Norovirus vaccine. A number of invention patents based on VLPs vaccine technology have been granted. Currently, the 4-valent HPV vaccine and the 9-valent HPV vaccine are in Phase III clinical stage while the 15-valent HPV vaccine and the recombinant enterovirus vaccine are in Phase I clinical stage Bovax is continuously exploring new applications for VLPs technology, and striving to establish a domestic leading VLPs platform.