em during RNA synthesis, which improves the replication fidelity of CoV [42]. Although these nsps have been demonstrated to play essential roles in viral replication, transcription and/or post-translational polyprotein processing [127], the nsp12–16 of PEDV and other CoVs are poorly characterized to date, except for SARS-CoV.

4. Innate Immunity during PEDV Infection
Host cells generally defend against virus infection by mounting an innate antiviral immune response to preve