Development and evaluation of a virus-like particle PEDV vaccine based on MS2 bacteriophage.

Porcine epidemic diarrhea virus (PEDV) can infect pigs of all ages, causing porcine epidemic diarrhea and resulting in significant losses to the global pig farming industry. The virus causes epidemic diarrhea and represents a significant threat to the global swine industry. To enhance vaccine safety and protective efficacy, a PEDV nanoparticle vaccine (PEDV-MS2 VLP) based on MS2 bacteriophages was developed. The MS2 phage coat (MS2 VLP) self-assembles into nanoparticles within Escherichia coli. It is conjugated to the PEDV RBD antigen via the SpyTag-SpyCatcher system, forming a structure mimicking the natural virus. Subcutaneous immunization of BALB/c mice with PEDV-MS2 VLP at days 0 and 14 resulted in a 100-fold increase in neutralizing titers and robust antigen-specific IgG responses. Additionally, PEDV-MS2 VLP induced high levels of cytokines (TNF-α, IFN-γ). The vaccine showed no significant toxicity to the liver, kidneys, or heart in mice. In summary, PEDV-MS2 VLPs demonstrate excellent safety and are a novel candidate vaccine for porcine epidemic diarrhea virus.