Hage J J, Glas R D, Westra H H, Maris-Veldhuis M A, Van Oirschot J T, Rijsewijk F A
Animal Health Service in The Netherlands, Drachten, Netherlands.
Vet Microbiol. 1998 Feb 28;60(2-4):87-98. doi: 10.1016/s0378-1135(97)00152-1.
Six heifers were vaccinated intranasally with the live bovine herpesvirus 1 (BHV1) temperature-sensitive (ts) vaccine strain RBL106 within 3 weeks of birth. These calves most likely still had maternal antibodies against BHV1. Thereafter, these heifers were vaccinated several times with an experimental BHV1 glycoprotein-D (gD) subunit vaccine. At the age of 3 years these 6 heifers were seronegative in the BHV1 gB and gE blocking ELISAs, but had neutralizing antibodies against BHV1, probably induced by the vaccinations with the gD subunit vaccine. Five of these 6 heifers excreted BHV1 after treatment with dexamethasone. Restriction enzyme analysis of the genome of the excreted viruses revealed that all 5 isolates had a BHV1.1 genotype and that isolates of 3 heifers were not obviously different from the ts-vaccine strain. The restriction enzyme fragment pattern of the isolate of 1 heifer was clearly different from the pattern of the ts-vaccine strain. It is concluded that cattle can be seronegative against BHV1 gB and gE but can still carry BHV1 in a latent form. This finding strongly suggests that there are completely BHV1 seronegative cattle that are latently infected with BHV1. The impact of this finding on BHV1 eradication programmes is discussed.
6头小母牛在出生后3周内通过鼻内接种活的牛疱疹病毒1型（BHV1）温度敏感（ts）疫苗株RBL106。这些小牛很可能仍具有针对BHV1的母源抗体。此后，这些小母牛多次接种实验性BHV1糖蛋白D（gD）亚单位疫苗。在3岁时，这6头小母牛在BHV1 gB和gE阻断ELISA中呈血清阴性，但具有针对BHV1的中和抗体，可能是由gD亚单位疫苗接种诱导产生的。这6头小母牛中有5头在接受地塞米松治疗后排出了BHV1。对排出病毒基因组的限制性内切酶分析表明，所有5株分离株均具有BHV1.1基因型，且3头小母牛的分离株与ts疫苗株无明显差异。1头小母牛的分离株的限制性内切酶片段模式与ts疫苗株的模式明显不同。结论是，牛可能对BHV1 gB和gE呈血清阴性，但仍可潜伏携带BHV1。这一发现强烈表明存在完全对BHV1血清阴性但潜伏感染BHV1的牛。讨论了这一发现对BHV1根除计划的影响。
