Vaccine genotype and route of administration affect pseudorabies field virus latency load after challenge

• Published in: Veterinary microbiology Vol. 62; no. 2; pp. 81 - 96
• Main Authors: Vilnis, Aivars, Sussman, Michael D, Thacker, Brad J, Senn, Michael, Maes, Roger K
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.1998; Elsevier Science
• Subjects: Administration, Intranasal; AIDS/HIV; Alphaherpesvirus; Animals; AUJESZKY VIRUS; Aujeszky's disease virus; Biological and medical sciences; Body Weight; CERDO; DNA, Viral - analysis; Enzyme-Linked Immunosorbent Assay - veterinary; Fundamental and applied biological sciences. Psychology; GENOTIPOS; GENOTYPE; GENOTYPES; Herpesvirus 1, Suid - genetics; Herpesvirus 1, Suid - immunology; Herpesvirus 1, Suid - pathogenicity; Injections, Intramuscular - veterinary; Latency; LIVE VACCINES; Luminescent Measurements; Male; Microbiology; Neutralization Tests - veterinary; PATHOGENICITY; PATOGENICIDAD; PCR; Polymerase Chain Reaction - veterinary; PORCIN; POUVOIR PATHOGENE; Pseudorabies - immunology; Pseudorabies - prevention & control; Pseudorabies Vaccines; Pseudorabies virus; Quantitative PCR; Respiratory Tract Diseases - immunology; Respiratory Tract Diseases - prevention & control; Respiratory Tract Diseases - veterinary; SWINE; Swine Diseases - immunology; Swine Diseases - prevention & control; Trigeminal Ganglion - chemistry; Trigeminal Ganglion - physiopathology; Trigeminal Ganglion - virology; VACCIN VIVANT; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Vaccines, Attenuated - administration & dosage; Vaccines, Attenuated - genetics; Vaccines, Attenuated - immunology; VACUNA VIVA; Viral Load - veterinary; Viral Vaccines - administration & dosage; Viral Vaccines - genetics; Viral Vaccines - immunology; Virology; Virulence; VIRUS D'AUJESZKY; VIRUS DE AUJESZKY; Virus Latency - immunology; Virus Shedding; Alphaherpesvirus; Aujeszky's disease virus; Pseudorabies virus; Quantitative PCR; Latency; Herpesviridae; Vaccination; Alphaherpesvirinae; Genotype; Vaccine; Route of administration; Infection; Virus; Aujeszky virus; Vertebrata; Aujeszky disease; Mammalia; Efficiency; Swine; Viral disease; Animal; Artiodactyla; Veterinary; Ungulata
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/S0378-1135(98)00200-4

The influence of vaccine genotype and route of administration on the efficacy of pseudorabies virus (PRV) vaccines against virulent PRV challenge was evaluated in a controlled experiment using five genotypically distinct modified live vaccines (MLVs) for PRV. Several of these MLVs share deletions in specific genes, however, each has its deletion in a different locus within that gene. Pigs were vaccinated with each vaccine, either via the intramuscular or intranasal route, and subsequently challenged with a highly virulent PRV field strain. During a 2-week period following challenge with virulent PRV, each of the vaccine strains used in this study was evaluated for its effectiveness in the reduction of clinical signs, prevention of growth retardation and virulent virus shedding. One month after challenge, tissues were collected and analyzed for virulent PRV latency load by a recently developed method for the electrochemiluminescent quantitation of latent herpesvirus DNA in animal tissues after PCR amplification. It was determined that all vaccination protocols provided protection against clinical signs resulting from field virus challenge and reduced both field virus shedding and latency load after field virus challenge. Our results indicated that vaccine efficacy was significantly influenced by the modified live vaccine strain and route of administration. Compared to unvaccinated pigs, vaccination reduced field virus latency load in trigeminal ganglia, but significant differences were found between vaccines and routes of administration. We conclude that vaccine genotype plays a role in the effectiveness of PRV MLVs.