Development and Immunological Evaluation of O Specific Antigen from Salmonella enterica Serovar Paratyphi B: A Novel Candidate for Vaccine Development

Abstract

Enteric fever, resulting from different Salmonella species such as S. typhi and S. paratyphi A and B, continues to pose a major public health challenge in developing countries. Although Vi polysaccharide-based vaccines offer effective protection against S. typhi, they fail to safeguard against S. paratyphi B because these serovars lack the Vi antigen. Currently, there is no licensed vaccine available for Salmonella Paratyphi B, highlighting a critical gap in preventive measures against this pathogen. To address this issue, researchers have focused on the O antigen, a crucial component of Gram-negative bacteria, as a potential vaccine candidate. The investigation outlined in the abstract focuses on the extraction, refinement, and evaluation of the immunogenic properties of the O antigen derived from Salmonella paratyphi B using a murine model. The research encompasses large-scale production, purification, and analytical characterization of the S. paratyphi B O-antigen. The purified antigen demonstrated high immunogenicity in the mouse model, suggesting its potential as a novel vaccine candidate. This research contributes to the development of a future paratyphoid fever vaccine, potentially addressing the unmet need for protection against S. paratyphi B infections.