Sarvesh Tayshete

Infectious Bovine Rhinotracheitis (IBR) is endemic in India, causing significant losses to dairy enterprises. Until recently, the unavailability of an indigenously manufactured vaccine and the high cost of imported vaccines limited national vaccination efforts. However, an indigenously developed and manufactured inactivated DIVA vaccine has now become available. The exact strategies that other countries have employed for the successful control of IBR may not be applicable in India due to the differences in the production systems and the social values. Hence, we have employed linear deterministic modeling to study the benefits, both in terms of the protection of the animals from the disease and the costs, of vaccination against IBR towards proposing an optimal strategy for immunization-based control of the disease in India. Our findings emphasize the need for proper vaccination practices, appropriate farm biosecurity measures, and biannual re-vaccinations to achieve the desired endpoints in a vaccination program. Based on our findings, a vaccination program aiming for primary vaccination with two doses followed by continuing bi-annual re-vaccination with a single dose to achieve 70% vaccination coverage in the cattle population can be recommended for the control of IBR in India.

Background: Infectious Bovine Rhinotracheitis (IBR), Infectious Pustular Balanoposthitis (IPB), Infectious Pustular Vulvovaginitis (IPV), late-term abortions, and neurological and systemic disease are common manifestations of Bovine Herpesvirus-1 (BoHV-1) infections. IBR is enzootic to India and several other countries across the world. Globally, both live attenuated and inactivated vaccines are available commercially for the control of the disease. This communication reports the results of an open-label, randomized field trial of an inactivated IBR marker vaccine in cattle. Methods: An indigenously developed, inactivated, glycoprotein-E (gE)-deleted marker vaccine was subjected to a field trial involving 90 healthy cattle of more than three months of age, evaluating its safety and immunogenicity. Results: Vaccination was safe without any adverse and serious adverse events, except a self-limiting and self-subsiding induration at the site of injection in a few cases. The vaccine caused elevation of body temperature but within normal physiological range; no derangements in feed intake or milk yield were recorded. A total of 90% of the subjects developed protective titers of SNT₅₀ ≥ 8 after receiving both doses of initial vaccination and maintained protective titers until 180 days thereafter. Conclusions: Altogether, our findings uphold that the indigenously developed, inactivated gE-deleted marker vaccine against IBR is safe and results in protective levels of immunity for at least six months in cattle of more than three months of age.