Department of Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki (AUT), 54124, Thessaloniki, Greece.
Laboratory of Anatomy Histology and Embryology, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki (AUT), 54124, Thessaloniki, Greece.
Vet Res. 2022 Jun 22;53(1):47. doi: 10.1186/s13567-022-01063-8.
The present study investigates the pathogenicity of two recently isolated strains of Suid herpesvirus 1 (SuHV1), the Greek strain Hercules and the Chinese strain HeN1, in unvaccinated pigs and in pigs vaccinated with a Bartha-K61 strain. In an experiment performed in negative pressure kiosks (isolators), 45-day old seronegative pigs previously oronasally /intramuscularly vaccinated with the Bartha-K61 vaccine strain, along with unvaccinated controls, were challenged either with the Hercules strain or the HeN1 strain of SuHV1. All animals were observed daily for clinical signs and body temperature and nasal swabs, faeces, blood and bodyweight were collected up to a maximum period of 20 days post-challenge (dpc). The results showed that, in the unvaccinated pigs, HeN1 strain was more virulent than the Hercules strain, with increased mortality, shorter time to death and higher group clinical score (p < 0.05). However, after vaccination with the Bartha-K61 vaccine, there was a drastic reduction in morbidity, mortality, bodyweight loss and virus excretion to almost a similar extent in both strains (p < 0.05). No significant differences were seen among the pigs of the two vaccinated groups compared to unvaccinated unchallenged controls, except a slight elevation in body temperature and in clinical score in the HeN1 vaccinees at 2 and 3 dpc, while bodyweight gain was similar to that of the negative control pigs. Our study showed that despite differences in virulence, the standard vaccination scheme with the Bartha-K61 strain could equally protect nursery pigs against both the European and Chinese strains.
本研究调查了最近分离的两种猪疱疹病毒 1 （SuHV1），即希腊 Hercules 株和中国 HeN1 株，在未接种疫苗的猪和接种巴氏 K61 疫苗株的猪中的致病性。在负压隔离器（隔离器）中进行的实验中，将先前经口鼻 /肌肉接种巴氏 K61 疫苗株的 45 日龄血清阴性猪与未接种疫苗的对照猪一起，用 Hercules 株或 HeN1 株 SuHV1 进行攻毒。所有动物每天观察临床症状和体温，并采集鼻拭子、粪便、血液和体重，最长观察 20 天（攻毒后）。结果表明，在未接种疫苗的猪中，HeN1 株比 Hercules 株更具毒力，死亡率增加，死亡时间缩短，群体临床评分更高（p<0.05）。然而，用巴氏 K61 疫苗接种后，两种毒株的发病率、死亡率、体重减轻和病毒排出量均急剧减少，几乎相同（p<0.05）。与未接种未攻毒的对照组相比，两接种组的猪之间没有明显差异，除了在攻毒后 2 和 3 天，HeN1 疫苗接种猪的体温和临床评分略有升高，而体重增加与阴性对照猪相似。我们的研究表明，尽管毒力存在差异，但巴氏 K61 株的标准接种方案同样可以保护仔猪免受欧洲和中国毒株的侵害。
