Bovine Adenovirus 3-Based Viral Vectors for Veterinary Vaccine Development: Progress, Limitations, and Future Directions

Abstract

Simple Summary Vaccines are essential for preventing infectious diseases in animals, but many existing vaccines still have limitations, especially for diseases that enter through the nose, lungs, or digestive tract. This review discusses bovine adenovirus, a virus originally associated with cattle, as a possible tool for carrying vaccine instructions into animal cells. This approach may help the body produce protective immune responses without the vaccine virus becoming part of the animal’s genetic material. The aim of this review is to summarize how bovine adenovirus-based vaccine carriers have been developed, how they can be engineered, what immune responses they may stimulate, and how they may be used against important animal diseases. Available studies suggest that these vaccine carriers can deliver different disease targets, stimulate antibody and immune-cell responses, and may be useful for respiratory diseases, combined vaccines, and diseases shared between animals and humans. However, this technology is still developing. More studies are needed to confirm safety, effectiveness in target animal species, large-scale production, and regulatory acceptance. If these challenges are addressed, bovine adenovirus-based vaccine carriers may become useful tools for improving livestock health, reducing disease losses, and supporting public health.