Development of experimental GBS vaccine for mucosal immunization

Area of Science:

• Microbiology
• Vaccinology
• Immunology

Background:

• Streptococcus agalactiae (group B Streptococcus, GBS) is a major cause of neonatal sepsis, meningitis, and pneumonia.
• Despite GBS being a significant global health concern, no effective vaccine is currently available.
• Developing a safe and effective GBS vaccine remains a critical unmet medical need.

Purpose of the Study:

• To engineer a novel live vaccine candidate for Streptococcus agalactiae.
• To evaluate the immunogenicity and protective efficacy of the engineered vaccine in a preclinical mouse model.

Main Methods:

• Engineered a live vaccine strain by incorporating the GBS surface protein Bac into a probiotic Enterococcus fimbrial protein.
• Administered the engineered vaccine intranasally, orally, and intravaginally in mice.
• Assessed systemic and local immune responses and protection against GBS challenge.

Main Results:

• The engineered vaccine successfully induced specific systemic and local immune responses in mice.
• Vaccination via intranasal, oral, or intravaginal routes conferred protection against GBS challenge.
• The novel vaccine platform demonstrated potential for broad applicability.

Conclusions:

• The engineered live vaccine strain shows promise as a safe and effective strategy against Streptococcus agalactiae.
• The study highlights the potential of using probiotic bacteria as delivery vehicles for GBS vaccines.
• Further development could lead to a much-needed vaccine to prevent GBS-related neonatal diseases.