Advances and applications of vectored vaccines in animal diseases

Abstract Viral vectors have prodigious potential to be used in gene therapy and vaccines. Viral vector-based vaccines, unlike regular vaccines, work without an adjuvant. These vaccines provide long-term protective immunity by eliciting a cell-mediated immune response, thereby enabling cytotoxic T- lymphocytes to eliminate virus-infected cells. Since the early 1970s, several types of viral vector-based vaccines have been studied and, developed, where several are in use as vectored-vaccines, while many are still under clinical trials. Each type of vectored vaccine harbors characteristic features derived from the wild type virus as well as foreign DNA inserted. Additionally, these vectored vaccines also carry parental virus-related risks with them. With the advancement in technology, these vectored vaccines have been genetically manipulated to enhance efficacy and safety, lower the administration dose, and aid in industry-scale manufacturing. Here, we further elaborate on the key challenges faced by vectored vaccines and their growing applications.