Advancements in liposome-based vaccines: A comprehensive review of mechanisms and applications

Liposome-based vaccines represent a significant advancement in immunotherapy due to their versatile ability to encapsulate and present antigens, adjuvants, and targeting ligands. These lipid vesicles, with their biocompatible and adaptable structure, offer enhanced immunogenicity, prolonged antigen exposure, and reduced reactogenicity. By encapsulating therapeutic agents, liposomes protect antigens from degradation and facilitate controlled release, increasing vaccine stability and efficacy. Surface modifications of liposomes enable antigen display strategies that mimic natural immune responses, effectively engaging immune cells. This display, combined with liposome-mediated delivery of adjuvants, amplifies both humoral and cellular immunity by activating dendritic cells, macrophages, T cells, and B cells. Liposomes also allow multivalent vaccine designs, targeting multiple pathogen epitopes, which is crucial for combating complex infections. Advanced techniques, such as covalent conjugation, metal-chelation, and lipid tail anchoring, enhance antigen presentation and immune cell engagement. The size, surface charge, and lipidic structure of liposomes are critical in determining their interaction with immune cells and impact their role as vaccine adjuvant-delivery systems. This review explores the recent innovations in liposome-based vaccines, focusing on mechanisms of antigen presentation, immune activation, and memory formation. The findings underscore the potential of liposomal platforms to serve as a next-generation vaccine technology capable of providing robust and lasting immune responses.