Abstract

Emerging porcine epidemic diarrhea viruses (PEDVs) have caused large economic losses since 2010, and G2b is the prevalent globally epidemic genotype. Given the fastidious isolation of emerging PEDV in cell culture and difficulties in retaining the isolate infectivity upon further in vitro passage, highly attenuated recombinant vesicular stomatitis virus (rVSV MT ) was used as a vector to express the PEDV spike (S) protein, aiming to develop a subunit vaccine against G2b viruses. An S protein with 19 of its cytoplasmic domain amino acids deleted could be incorporated into VSV particles, generating rVSV MT (VSV MT -S Δ19 ) with high efficiency. Our results suggest that VSV MT -S Δ19 could effectively induce PEDV-specific immunity in pigs via intramuscular, but not intranasal, immunization. Notably, immunizations of sows with VSV MT -S Δ19 provided protective lactogenic immunity against a virulent G2b PEDV challenge in piglets. Consequently, recombinant VSV MT may be a promising platform for preparing a subunit vaccine against PEDV.