Harnessing reverse vaccinology for the design and validation of mRNA vaccine targeting the glycoprotein of human metapneumovirus (HMPV)

Abstract

Human metapneumovirus (HMPV) is a major cause of respiratory illness among vulnerable populations worldwide, yet no licensed vaccine or specific antiviral therapy is currently available. This study aimed to design novel multi-epitope mRNA vaccine candidates against HMPV using an immunoinformatics-based approach. Globally representative HMPV glycoprotein sequences were analyzed to predict cytotoxic T-lymphocyte (CTL), helper T-lymphocyte (HTL), and linear B-cell (LBL) epitopes. Selected epitopes were assembled into two multi-epitope mRNA vaccine constructs. The constructs were further evaluated for antigenicity, allergenicity, toxicity, and physicochemical properties using in silico tools. Structural stability and immune receptor interactions were assessed through molecular modeling and molecular docking analyses against Toll-like receptors 2 and 4 (TLR2 and TLR4). Both vaccine constructs demonstrated high antigenicity, while remaining non-toxic and non-allergenic, with favorable physicochemical characteristics. Structural analyses indicated stable conformations of the vaccine models. Molecular docking studies revealed strong binding affinities with TLR2 and TLR4, suggesting their ability to effectively stimulate innate and adaptive immune responses. The two proposed multi-epitope mRNA vaccine constructs showed promising immunogenic, safety, and structural properties in silico, highlighting their potential as candidate vaccines against HMPV. These findings provide a strong foundation for further experimental validation and future vaccine development.