Virus-like particles vaccine of porcine epidemic diarrhea virus spike 1 protein induces protective immunity challenge in piglets.

Porcine epidemic diarrhea virus (PEDV) is a highly contagious intestinal disease that impairs piglet growth and development, causing significant economic losses. Therefore, developing an effective vaccine is crucial for preventing and controlling PEDV. This study used a eukaryotic expression system to assemble S1 with Ferritin into virus-like particles (S1-F-VLP) via SpyTag-SpyCatcher and confirmed their immunogenicity and protective efficacy. The results showed no mouse deaths or sow abortions during S1-F-VLP vaccination, confirming its safety. In mouse, sow and piglet models, S1-F-VLP vaccination induced high levels of PEDV-specific antibodies including serum IgG, IgA (IgA) and neutralizing antibodies (NAbs). The piglet challenge test results showed that, compared with the control group, S1-F-VLP-vaccinated piglets had significantly lower diarrhea score and intestinal viral loads, and exhibited markedly reduced intestinal pathological damage. These results indicate that S1-F-VLP confers robust immune protection against the highly virulent PEDV strain and holds promise as a clinical candidate vaccine.