Oral vaccine based on a surface immunogenic protein mixed with alum promotes a decrease in Streptococcus agalactiae...

Area of Science:

• Vaccinology
• Microbiology
• Immunology

Background:

• The Surface Immunogenic Protein (SIP) of Group B Streptococcus (GBS) is a promising vaccine target.
• Previous studies indicate SIP induces protection against GBS challenge and intranasal immunization elicits similar effects.

Purpose of the Study:

• To evaluate the immunogenicity and efficacy of an oral SIP-based vaccine formulated with alum in a mouse model.
• To assess the vaccine's ability to reduce GBS colonization and induce a specific immune response.

Main Methods:

• Oral immunization of mice with an alum-adjuvanted SIP-based vaccine.
• Assessment of vaginal GBS colonization levels.
• Measurement of SIP-specific antibodies and their opsonophagocytic activity.
• Analysis of T-cell responses, including cytokine production (IFN-γ, TNF-α, IL-10, IL-2) and T-bet expression.

Main Results:

• The oral SIP-based vaccine significantly reduced vaginal GBS colonization in mice.
• Specific SIP-antibodies with opsonophagocytic activity against GBS were induced.
• A Th1-type humoral response was observed, characterized by T-cell activation producing IFN-γ, TNF-α, IL-10, and IL-2, along with increased T-bet expression.

Conclusions:

• An oral SIP-based vaccine formulated on alum is a viable strategy for reducing GBS colonization.
• The vaccine elicits a robust immune response, including antibody production and Th1-type T-cell activation.
• This oral vaccine represents a novel alternative for developing a Group B Streptococcus vaccine.