Animal Virus Evolution under Vaccine Pressure: From Immune Escape Mechanisms to Next-Generation Vaccine Design

Abstract

This review examines the critical challenge of evolving animal virus resistance to vaccines, a phenomenon threatening veterinary medicine, global food security, and public health. While effective for controlling bacterial diseases, vaccination against rapidly mutating RNA viruses often imposes strong selective pressures, driving the emergence of antigenic variants that evade host immunity. These vaccines escape mutants, evidenced in viruses like canine parvovirus (CPV), avian influenza (AIV), and foot-and-mouth disease (FMD), lead to outbreaks in vaccinated populations and complicate disease management. The paper elucidates the mechanisms behind this resistance, primarily genetic mutations in antigenic sites and sophisticated immune evasion strategies, which enable viruses to circumvent neutralization by vaccine-induced antibodies. It critically evaluates the limitations of current vaccine technologies, including inactivated, live-attenuated, and subunit vaccines, noting that imperfect immunity can inadvertently promote the selection of resistant strains. To address this ongoing evolutionary arms race, the authors advocate for a paradigm shift in vaccine design. They propose leveraging advanced technologies such as viral vector platforms, structural biology, and predictive modeling to develop next-generation vaccines targeting conserved epitopes. Furthermore, the review emphasizes the necessity of global surveillance programs to monitor viral evolution in real-time and calls for a collaborative, interdisciplinary approach to create more robust and future-proof vaccination strategies, thereby mitigating the risk of vaccine-driven viral and ensuring long term efficacy.