A Recombinant Alpha-Like Protein Subunit Vaccine (GBS-NN) Provides Protection in Murine Models of Group B...

Area of Science:

• Microbiology
• Immunology
• Vaccinology

Background:

• Group B Streptococcus (GBS) poses risks during pregnancy, causing preterm labor, stillbirths, and neonatal infections, with rising adult infection rates.
• The GBS-NN vaccine, targeting GBS Alpha C and Rib proteins, is safe in nonpregnant women but requires evaluation for use during pregnancy.
• Mouse models are utilized to assess GBS infection outcomes and vaccine efficacy relevant to human GBS disease.

Purpose of the Study:

• To evaluate the efficacy of the GBS-NN vaccine in mouse models of systemic and pregnancy-associated Group B Streptococcus infections.
• To determine if maternal vaccination with GBS-NN confers protection to neonates against GBS challenge.

Main Methods:

• Antibody responses (IgG titers) were measured by ELISA after GBS-NN vaccine or adjuvant administration.
• Vaccine efficacy was assessed by comparing GBS recovery in systemically infected mice and pregnancy-associated infection outcomes in vaccinated dams versus controls.
• Neonatal survival was evaluated after intranasal GBS challenge in offspring from vaccinated mothers.

Main Results:

• GBS-NN vaccination induced higher GBS-NN-specific IgG titers that recognized GBS surface proteins.
• Vaccinated mice showed reduced GBS burden during systemic infection and fewer in utero fetal deaths in pregnant dams.
• Maternal vaccination with GBS-NN improved neonatal survival following intranasal GBS challenge.

Conclusions:

• The GBS-NN vaccine demonstrates efficacy in preclinical models of GBS infection, including systemic and perinatal contexts.
• Maternal GBS-NN vaccination facilitates the transfer of protective antibodies to neonates, offering protection against GBS challenge.