Name
Adenovirus-based vaccine for Epizootic Hemorrhagic Disease Virus (EHDV) protects against virulent homologous and heterologous challenge.
Presenter
Noemí Sevilla, Centro de Investigación en Sanidad Animal (CISA)-INIA-CSIC
Co-Author(s)
Pablo Nogales-Altozano, Laro Gómez-Marcos, José M. Rojas, Alicia Rivera-Rodríguez, Verónica Martín and Noemí Sevilla.
Centro de Investigación en Sanidad Animal (Animal Health Research Centre), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (CISA-INIA/CSIC), Valdeolmos, Madrid, Spain
Abstract Category
Vaccines
Abstract
Epizootic hemorrhagic disease virus (EHDV) is an emerging threat to the European ruminant industry, causing significant economic losses. Current vaccines lack DIVA (differentiation of infected from vaccinated animals) capability and provide limited cross-serotype protection. In this study, we developed replication-defective adenovirus vaccines expressing EHDV structural antigens VP2 from EHDV-8 (Ad-VP2-8) and VP7 from EHDV-2 (Ad-VP7) to evaluate their efficacy in a murine model. Immunization with Ad-VP2-8 and Ad-VP7 elicited cross-reactive T cell responses between EHDV-6 and -8. Ad-VP2-8 induced high neutralizing antibody titers against EHDV-8 and lower titers against EHDV-6, indicating partial cross-serotype reactivity. While Ad-VP2-8 alone protected against homologous EHDV-8 challenge, it failed against heterologous EHDV-6, with high viremia similar to control animals. In contrast, Ad-VP7 alone provided protection against both EHDV-6 and EHDV-8, though viremia persisted, suggesting non-sterile immunity. Mice vaccinated with a combination of Ad-VP7 and Ad-VP2-8 were protected against both EHDV-6 and EHDV-8, with significantly reduced or undetectable viremia. This demonstrates that combining VP2 and VP7 enhances protective efficacy and cross-serotype immunity. Our findings highlight the potential of adenovirus-based vaccines as a DIVA-compatible strategy for EHDV control. By inducing strong, cross-reactive immune responses, this approach could improve disease surveillance and management, ultimately mitigating EHDV’s impact on the livestock industry.