Designing of Multi-Epitope Peptide Vaccine Based on Outer Membrane Proteins OmpF, OmpC, and PgtE of Typhi.

Consumption of contaminated water and foods by Typhi cause the most common enteric disease known as Typhoid fever in both humans and animals. Despite the existence of various vaccines but infectious diseases remain a major cause of mortality worldwide. Nowadays, in-silico tools design a reliable and stable vaccine to combat such infections. The study aimed to design and evaluate a multi-epitope vaccine based on the outer-membrane proteins of Typhi. B-cells and T-cells epitopes were predicted. Predicted epitopes were connected by AAY, KK, and GPGPG linkers. Heparin-Binding Hemagglutinin Adhesin (HBHA) has been attached to the N-terminal of the final vaccine as a potent immune adjuvant. Epitope's antigenicity, allergenicity, immunogenicity, and physicochemical characteristics were defined using in-silico tools. Molecular docking of vaccine-TLR4 was done. ∆G of vaccine-TLR4 is -3.91×10 Kcal mol with 1.93 RMSD. The results indicated protein was stable and non-allergen. In conclusion, the multi-epitope vaccine base on outer membrane proteins of the Typhi bacterium might be considered to combat typhoid fever.