Immunoinformatics-Driven Design and In Silico Validation of a Multi Epitope Subunit Vaccine Targeting Norovirus

Norovirus, a non-enveloped, positive-sense single-stranded RNA virus belonging to the Caliciviridae family, is a major causative agent of acute gastroenteritis (AGE) outbreaks worldwide. It is primarily transmitted via the fecal–oral route, with clinical manifestations including abdominal pain, watery diarrhoea, nausea, and vomiting. In the United States alone, norovirus is estimated to cause approximately 19–21 million cases annually. Emerging variants, such as the GII.17 genotype, have been implicated in an increasing number of outbreaks across multiple countries, highlighting the urgent need for effective preventive strategies. In this study, an immunoinformatics-based approach was employed to design and evaluate a multi-epitope subunit vaccine candidate against norovirus. Three viral proteins—capsid protein (UniProt ID: A7YK10), small protein (A7YK11), and polyprotein (A7YK09)—were selected for epitope-based vaccine design. B-cell and T-cell epitopes were predicted using the Immune Epitope Database (IEDB) and subsequently screened for antigenicity (VaxiJen), allergenicity (AllerTOP v2.1), toxicity (ToxinPred), and population coverage. Physicochemical properties were evaluated using ProtParam, and secondary structure analysis was performed to assess the structural feasibility of the vaccine construct. The finalized multi-epitope vaccine construct was further subjected to molecular docking analyses to evaluate its binding affinity with key immune receptors, including MHC class I, MHC class II, and Toll-like receptor 4 (TLR4), providing insight into its potential immunogenic interactions. While the computational analyses indicate that the designed construct is a promising vaccine candidate, further experimental validation, including in vitro expression and in vivo immunogenicity and efficacy studies, will be required to confirm its protective potential.