A further study on relationships between herpes simplex virus and Bovid herpesvirus-2

Calves exposed by intravenous or intradermal inoculation with Herpes simplex virus (HSV), types 1 and 2, remained clinically normal and HSV was not recovered from nasal secretion nor blood samples. However, the clinical response of calves pre-inoculated with HSV, to Bovid herpesvirus-2 (BH-2) challenge infection was much milder than that in the challenge control calves, and the titer of BHV-2 by skin titration underwent a significant (2-2.5 log units) reduction in the HSV pre-inoculated calves. Inoculation of calves with live HSV provided a much greater protection against BHV-2 challenge infection compared with the results of previous experiments in which a Triton X100-inactivated HSV antigen was used. It was speculated that the possibility of HSV replicating in cattle must still be considered an open question.