S. Typhi derived vaccines and a proposal for outer membrane vesicles (OMVs) as potential vaccine for typhoid fever

Area of Science:

• Microbiology
• Immunology
• Vaccine Development

Background:

• Typhoid fever is a severe systemic infection caused by Salmonella Typhi (S. Typhi), transmitted via the feco-oral route, and linked to poor sanitation.
• High rates of antibiotic resistance in S. Typhi strains (nearly 93%) necessitate alternative prevention strategies.
• Vaccination remains the most effective method for preventing typhoid fever.

Purpose of the Study:

• To review the characteristics of S. Typhi, including its pathogenicity, infection modes, epidemiology, and drug resistance patterns.
• To explore various S. Typhi components (Vi-polysaccharides, O-antigens, flagellar antigens, OMPs, and peptides) used in vaccine design.
• To propose the development of S. Typhi-derived outer membrane vesicles (OMVs) as a novel vaccine for typhoid fever.

Main Methods:

• Literature review on S. Typhi biology, epidemiology, and existing vaccine strategies.
• Analysis of S. Typhi components investigated for vaccine potential.
• Proposal for utilizing S. Typhi-derived OMVs in vaccine formulation.

Main Results:

• S. Typhi exhibits significant antibiotic resistance, underscoring the need for effective vaccines.
• Various S. Typhi antigens have been explored for vaccine development, with varying success.
• OMVs present a promising platform for delivering S. Typhi antigens for a robust immune response.

Conclusions:

• Developing novel vaccines against S. Typhi is critical due to widespread antibiotic resistance.
• S. Typhi-derived OMVs offer a potential new avenue for creating an effective typhoid fever vaccine.
• Further research into OMV-based vaccines could provide a vital tool for public health.