Emerging pseudorabies virus (PRV) variant has led to frequent outbreaks of PRV infection among Bartha-K61-vaccinated swine population in Chinese swine farms and caused high mortality in pigs of all age since late 2011. Here, we generated a gE/gI-deleted PRV (rPRVXJ-delgI/gE-EGFP) based on PRV variant strain (PRV-XJ) through homologous DNA recombination. Compared to parental strain, rPRVXJ-delgI/gE-EGFP showed similar growth kinetics in vitro. Its safety and immunogenicity were evaluated in weaned piglets. Our results showed that piglets immunized with rPRVXJ-delgI/gE-EGFP did not exhibit any clinical symptoms, and a high level of gB-specific antibody was detected. After lethal challenge with variant PRV (PRV-FJ strain), all vaccinated piglets survived without showing any clinical symptoms except slight fever within 7 days post-challenge. In unvaccinated piglets, typical clinical symptoms of pseudorabies were observed, and the piglets were all died at 5 days post-challenge. These results indicated that a live rPRVXJ-delgI/gE-EGFP vaccine could be a maker vaccine candidate to control the currently epidemic pseudorabies in China.
Yin Y, Xu Z, Liu X, Li P, Yang F, Zhao J, Fan Y, Sun X, Zhu L; A Live gI/gE-Deleted Pseudorabies Virus (PRV) Protects Weaned Piglets Against Lethal Variant PRV Challenge; Virus Genes. 2017 Apr 17. doi: 10.1007/s11262-017-1454-y. [Epub ahead of print] PMID: 28417300 DOI: 10.1007/s11262-017-1454-y