Different types of
vaccines against
Infectious Bovine Rhinotracheitis (IBR) are commercially available. Among these, inactivated
glycoprotein E (gE)-deleted
marker vaccines are commonly used, but their ability to induce passive immunity is poorly known. Here, we evaluated the passive immunity transferred from dams immunised with commercial inactivated gE-deleted
marker vaccines to calves. We vaccinated 12 pregnant cattle devoid of neutralising
antibodies against Bovine alphaherpesvirus 1 (BoHV-1) and divided them into two groups with 6 animals each. Both groups were injected with a different inactivated gE-deleted
marker vaccine administrated via intranasal or intramuscular routes. An additional 6 pregnant cattle served as the unvaccinated control group. After calving, the number of animals in each group was increased by the newborn calves. In the dams, the humoral immune response was evaluated before calving and, subsequently, at different times until post-calving day 180 (PCD180). In addition, the
antibodies in colostrum, milk, and in serum samples from newborn calves were evaluated at different times until PCD180. The results indicated that inactivated
glycoprotein E (gE)-deleted
marker vaccines are safe and produce a good humoral immune response in pregnant cattle until calving and PCD180. Moreover, results showed that, in calf serum, passive immunity persists until PCD180.