Virology Section, Department of Preventive Veterinary Medicine, Federal University of Santa Maria, Av. Roraima, 1000 Santa Maria, RS 97105-900, Brazil.
Vet Microbiol. 2011 Dec 29;154(1-2):14-22. doi: 10.1016/j.vetmic.2011.03.019. Epub 2011 Mar 26.
A recombinant bovine herpesvirus 5 lacking thymidine kinase and glycoprotein E genes (BoHV-5gEΔTKΔ) was evaluated as a live experimental vaccine. In a first experiment, ten-months-old calves were vaccinated intramuscularly (n=9) or remained as controls (n=8) and 42 days later were challenged with BoHV-5 or BoHV-1 intranasally. The four control calves challenged with BoHV-5 developed severe depression and neurological signs and were euthanized in extremis at days 13 and 14 pos-infection (pi); the five vaccinated animals challenged with BoHV-5 remained healthy. The titers of virus shedding were reduced (p<0.01) from days 3 to 7 post-infection (pi) in vaccinated animals. Control and vaccinated calves challenged with BoHV-1 presented mild transient respiratory signs; yet the magnitude of virus shedding was reduced (p<0.05) in vaccinated animals (days 5, 9 and 11pi). In a second experiment, young calves (100-120 days-old) were vaccinated (n=15) or kept as controls (n=5) and subsequently challenged with a BoHV-1 isolate. Control calves developed moderate to severe rhinitis and respiratory distress; two were euthanized in extremis at days 5 and 9 pi, respectively. In contrast, vaccinated animals were protected from challenge and only a few developed mild and transient nasal signs. The duration and titers of virus shedding after challenge were reduced (p<0.05) in vaccinated animals comparing to controls. In both experiments, vaccinated animals developed antibodies to gE only after challenge. These results demonstrate homologous and heterologous protection and are promising towards the use of the recombinant BoHV-5gEΔTKΔ in vaccine formulations to control BoHV-5 and BoHV-1 infections.
一株缺失胸苷激酶和糖蛋白 E 基因的重组牛疱疹病毒 5 型（BoHV-5gEΔTKΔ）被评估为活的实验疫苗。在第一项实验中，10 月龄的犊牛肌肉注射接种疫苗（n=9）或作为对照（n=8），42 天后通过鼻腔内接种 BoHV-5 或 BoHV-1 进行攻毒。用 BoHV-5 攻毒的 4 头对照牛出现严重抑郁和神经症状，并在感染后第 13 和 14 天处于病危状态被安乐死；5 头接种疫苗的动物攻毒后保持健康。接种疫苗的动物在攻毒后第 3 至 7 天的病毒脱落量减少（p<0.01）。用 BoHV-5 攻毒的对照和接种疫苗的犊牛出现轻微的一过性呼吸道症状；然而，接种疫苗的动物的病毒脱落量减少（p<0.05）（攻毒后第 5、9 和 11 天）。在第二项实验中，将 100-120 日龄的犊牛（n=15）接种疫苗或作为对照（n=5），随后用 BoHV-1 分离株攻毒。对照犊牛出现中度至重度鼻炎和呼吸窘迫；2 头分别在感染后第 5 和 9 天被安乐死。相比之下，接种疫苗的动物受到保护免受攻毒，只有少数动物出现轻微和一过性的鼻症状。与对照组相比，接种疫苗的动物在攻毒后病毒脱落的持续时间和滴度降低（p<0.05）。在这两项实验中，接种疫苗的动物仅在攻毒后才产生针对 gE 的抗体。这些结果表明同源和异源保护，并为使用重组 BoHV-5gEΔTKΔ 疫苗制剂控制 BoHV-5 和 BoHV-1 感染提供了希望。
