Version 3: Development of Recombinant Proteins for Vaccine Candidates Against Serotype O and A of Foot and Mouth Disease Virus in Bangladesh

Frequent vaccine failure leading to recurrent outbreaks of Foot-and-Mouth Disease (FMD) in livestock populations necessitates the development of a customizable vaccine platform comprising potential antigenic determinants of circulating lineages of FMD viruses. Artificially designed, chimeric peptide-based recombinant vaccines are novel approaches to combat the phylogenetically diverse FMD Virus (FMDV) strains. Among seven recognized serotypes, only serotypes O and A are dominantly circulating in Bangladesh and neighboring countries of Asia, where transboundary transmission, recurrent outbreaks and emergence of novel lineages of FMDV are highly prevalent. The objective of this study was to develop multi-epitope recombinant peptides, procuring immunogenicity against circulating diverse genotypes of FMDV serotypes O and A. Two chimeric peptides, named B1 (41.0 kDa) and B3 (39.3 kDa), have been designed to incorporate potential B-cell and T-cell epitopes selected from multiple FMDV strains, including previously reported and newly emerged sub-lineages. After expression, characterization and immunization of guineapigs with considerable antigen load of B1 and B3 followed by the serological assays revealed the significant protective immunogenicity, developed from the higher (100 µg) doses of both antigens, against most of the currently prevalent serotype O and A strains of FMDV. The efficient expression, antigenic stability, and multivalent immunogenic potency of the chimeric peptides strongly indicate their credibility as novel vaccine candidates for existing serotypes O and A of FMDV in Bangladesh and surrounding territories.