A live gI/gE-deleted pseudorabies virus (PRV) protects weaned piglets against lethal variant PRV challenge

Virus Genes. 2017 Aug;53(4):565-572. doi: 10.1007/s11262-017-1454-y. Epub 2017 Apr 17.

Abstract

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.

Keywords: Efficacy; Marker vaccine; PRV variant; Safety; gE/gI deletion.

MeSH terms

  • Animals
  • Antibodies, Viral / immunology
  • Gene Deletion*
  • Herpesvirus 1, Suid / genetics*
  • Herpesvirus 1, Suid / immunology
  • Herpesvirus 1, Suid / metabolism
  • Pseudorabies / immunology
  • Pseudorabies / physiopathology
  • Pseudorabies / prevention & control
  • Pseudorabies / virology*
  • Swine
  • Swine Diseases / immunology
  • Swine Diseases / physiopathology
  • Swine Diseases / prevention & control
  • Swine Diseases / virology*
  • Vaccines, Attenuated / administration & dosage
  • Vaccines, Attenuated / genetics
  • Vaccines, Attenuated / immunology
  • Viral Envelope Proteins / administration & dosage
  • Viral Envelope Proteins / genetics*
  • Viral Envelope Proteins / immunology
  • Viral Vaccines / administration & dosage
  • Viral Vaccines / genetics
  • Viral Vaccines / immunology
  • Weaning

Substances

  • Antibodies, Viral
  • Vaccines, Attenuated
  • Viral Envelope Proteins
  • Viral Vaccines
  • glycoprotein E, Suid herpesvirus 1
  • pseudorabies virus glycoproteins