Construction and preliminary immunological evaluation of EV-G replicon expressing PEDV-COE-N region

Porcine epidemic diarrhea virus (PEDV) is a highly contagious virus that causes acute infectious disease in swine, with mortality rates in piglets reaching up to 100%. In recent years, PEDV has led to significant economic losses in China's pig industry. As there is no specific treatment for PEDV, vaccination remains a key strategy for its prevention and control. This study utilized the EV-G replicon system to develop a nucleic acid vaccine expressing the PEDV core neutralizing epitope (COE) region, which was evaluated through immunization of Kunming mice. The results demonstrated that the vaccine successfully induced high levels of specific IgG and neutralizing antibodies in the mice, while also significantly enhanced splenic lymphocyte proliferation, and increased the expression of IL-4 and IFN-γ cytokines. These findings indicate that the constructed pBluescript-EV-G-COE-N plasmid is an effective DNA replicon vaccine. Notably, immunized with pBluescript-EV-G-COE-N replicons with chitosan resulted in higher neutralizing antibodies and IFN-γ, suggesting the enhanced immune efficacy. The successful construction and preliminary immunological evaluation of the pBluescript-EV-G-COE-N replicon highlights its potential in PEDV vaccine development and offers valuable data for future research in new PEDV vaccine formulations.