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Updated: May 30, 2026

A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
Efficacy of polymeric encapsulated C5a peptidase-based group B streptococcus vaccines in a murine model
Donna A Santillan1, Karishma K Rai, Mark K Santillan
1Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
Objective:
The purpose was to examine in mice the efficacy of various polymeric-encapsulated C5a peptidase vaccine formulations in eliciting a long-term immune response and preventing group B streptococcus (GBS) infection.
Study Design:
C5a peptidase was encapsulated in semipermeable microspheres of poly(lactide-coglycolide) (PLGA). Female ICR mice were immunized with 0, 10, or 30 microg of encapsulated C5a peptidase within 2 different formulations of PLGA polymers. Booster doses were given at weeks 4 and 8. Antibody responses were measured by enzyme-linked immunosorbent assay at weeks 4, 8, 11, and 40. Vaginal challenges with GBS types 1a, III, and V were performed at week 12.
Results:
Thirty microgram doses of the 75:25 and 50:50 PLGA formulations generate the highest and most sustained C5a peptidase-specific immune responses. Mice that received encapsulated C5a peptidase were significantly protected from vaginal colonization compared with mice that received empty microspheres.
Conclusion:
Encapsulated C5a peptidase elicited significant immune responses and protection against a GBS challenge. C5a peptidase microsphere encapsulation has potential as a GBS vaccine.
