Genetic evolution of Akabane virus isolates and the protective efficacy of inactivated vaccines

Akabane virus infection can cause abortion, stillbirth in pregnant ruminants, and congenital malformations in newborns. It is prevalent in most regions of Asia, as well as parts of Africa and Europe, causing severe impacts on the livestock industry. Inactivated vaccines are one of the effective means of disease prevention. In this study, an AKAV strain (CH-JL-01-2022) belonging to genetic group I was isolated, and based on this strain, an inactivated vaccine was developed, with screening conducted for the inactivating agent and adjuvant. Formaldehyde can completely inactivate AKAV, and mixed with the Imject^® Alum adjuvant can induce the high differentiation of CD4⁺ and CD8⁺ T-cells and produce high levels of TNF-α. High titers of neutralizing antibodies can be detected 21 days post-vaccination with inactivated virus and adjuvant mixture The viral load and lesions in some organs after virus challenge can be reduced. It was found that formaldehyde is the optimal Inactivating agent and Imject^® Alum is the best adjuvant, laying a foundation for the development of AKAV vaccines.