A recombinant rabies virus (ERAGS) for use in a bait vaccine for swine

Abstract

PurposeRabies viruses (RABV) circulating worldwide in various carnivores occasionally cause fatal encephalitis in swine. In this study, the safety and immunogenicity of a recombinant rabies virus, the ERAGS strain constructed with a reverse genetics system, was evaluated in domestic pigs.Materials and MethodsGrowing pigs were administered 1 mL (108.0 FAID50/mL) of the ERAGS strain via intramuscular (IM) or oral routes and were observed for 4 weeks' post-inoculation. Three sows were also inoculated with 1 mL of the ERAGS strain via the IM route. The safety and immunogenicity in swine were evaluated using daily observation and a virus-neutralizing assay (VNA). Fluorescent antibody tests (FAT) for the RABV antigen and reverse transcriptase-polymerase chain reaction (RT-PCR) assays for the detection of the nucleocapsid (N) gene of RABV were conducted with brain tissues from the sows after necropsy.ResultsThe growing pigs and sows administered the ERAGS strain did not exhibit any clinical sign of rabies during the test period test and did develop VNA titers. The growing pigs inoculated with the ERAGS strain via the IM route showed higher VNA titers than did those receiving oral administration. FAT and RT-PCR assays were unable to detect RABV in several tissues, including brain samples from the sows.ConclusionOur results suggest that the ERAGS strain was safe in growing pigs and sows and induced moderate VNA titers in pigs.

Polyacrylate-GnRH Peptide Conjugate as an Oral Contraceptive Vaccine Candidate

“…The viability of oral immunization has been confirmed during development of swine vaccines against infectious diseases. Oral vaccines distributed as bait have produced antibody responses against classical swine fever virus [ 44 , 71 , 72 , 73 , 74 , 75 , 76 ], African swine fever virus [ 77 , 78 ] and rabies virus [ 79 ].…”

The Presence of Rabies Virus-Neutralizing Antibody in Wild Boars (Sus scrofa), a Non-Target Bait Vaccine Animal in Korea

“…The peak antibody response was observed at 60 days post-vaccination in raccoons vaccinated with ONRAB before challenge [ 23 ]. Following oral administration of recombinant rabies virus (ERAGS) to pigs, the antibody level was maintained after 2–4 weeks [ 31 ]. Although no study has examined the antibody response over time after oral rabies vaccination in wild boars, the maintaining of antibody levels for 2–4 weeks in pigs could be suggestive for the case in wild boars.…”