Specific Passive Immunity Reduces the Excretion of Glycoprotein E-Negative Bovine Herpesvirus Type 1 Vaccine Strain in Calves

We investigated the excretion of either a glycoprotein E (gE)-negative bovine herpesvirus type 1 (BHV1) vaccine strain or a conventional modified-live vaccine strain in both naive and passively immunised calves. The replication of gE-negative strain was considerably reduced in the maternally immunised calves, in comparison with the non-immune calves. On the other hand, the excretion of the gE-positive conventional vaccine strain was not reduced and even seemed to be prolonged in the presence of maternal antibodies. These results suggest that BHV1 gE may play a role in virus survival in the presence of antibodies.