FIG. 8.

BHV-1 neutralizing-antibody titers. Serum was collected from calves at the indicated times and stored at −20°C until it was tested. Standard testing was performed using constant amounts of virus (Cooper strain) and twofold dilutions of the serum. The Veterinary Diagnostic Services, University of Nebraska, Lincoln, performed the assay. Solid symbols represent calves infected with WT or LR rescued virus. Open symbols represent calves infected with LR mutant virus. Each time point represents at least 10 calves for each virus. Days 10 and 14 p.i. are statistically different (P < 0.005). See the legend to Fig. 5 for an explanation of the statistical methods used for this study.