Advancing peptide-based vaccines against viral pathogens: a narrative review

Peptide-based vaccines, utilizing defined B- and T-cell epitopes, have emerged over the past two decades as promising alternatives to conventional vaccine platforms. Their key advantages, including excellent safety profiles, precise immunological targeting, and ease of manufacture, position them as a versatile tool in modern immunology. However, the widespread clinical application of these vaccines is significantly challenged by inherent limitations, most notably their low inherent immunogenicity and susceptibility to enzymatic degradation in vivo, leading to structural instability and short half-lives. This review systematically examines the innovative strategies being developed to overcome these critical obstacles. It delves into advances in rational vaccine design, highlighting the pivotal role of bioinformatics and computational tools for precise epitope selection and the engineering of sophisticated multi-epitope constructs that elicit broader immune responses. Furthermore, we provide a comprehensive analysis of novel drug delivery systems, such as a diverse range of nanoparticle carriers (e.g., liposomes, polymer-based), and review the mechanism of action of next-generation adjuvants. These technologies are crucial for enhancing antigen presentation, protecting the peptide payload, and promoting robust, durable cellular and humoral immunity. By synthesizing current literature from databases like PubMed and Google Scholar, this review offers a detailed overview of recent progress in peptide vaccine development against viral pathogens, drawing on key findings from both preclinical and clinical studies. It highlights key findings from preclinical and clinical studies and provides insights into the mechanistic actions and future potential of these precision vaccines in combating evolving viral threats.