Immunization Against Group B Streptococci vs. Intrapartum Antibiotic Prophylaxis in Peripartum Pregnant Women and their Neonates: A Review

Group B streptococcus (GBS) is an organism that has an immense global impact on neonatal morbidity and mortality. GBS is known to colonize the gastrointestinal and genitourinary tracts of infected pregnant women. Transmission to the neonate is achieved during labor and delivery. Complications of neonatal infection include sepsis, meningitis, and pneumonia. Preventative measures are needed to reduce the disease burden. The current method of prophylaxis being utilized is intrapartum antibiotics. Though effective, it presents limitations that include a required, lengthy duration of treatment, increased antibiotic resistance, and lack of late-onset disease coverage. Recent studies are exploring alternative methods of prophylaxis such as vaccination. Vaccination provides coverage of both early and late-onset disease to infected women who are unable to complete the required four hours of antibiotic course intrapartum, women with resistance to antibiotic infections, and women delivering in resource-poor areas without access to antibiotics. An investigational CRM197 conjugated trivalent vaccine has shown a good immunogenicity profile against the three most prevalent serotypes. The vaccine induced antibodies freely cross the placenta and persist in a neonate for up to 90 days after birth. Additionally, the vaccine possesses a safety profile free of any serious systemic adverse effects and only mild pain at the injection site. Future studies should focus on investigating the effect of the vaccine on maternal rectovaginal acquisition and subsequent vaginal colonization, as well as the expansion of vaccine coverage to all 10 serotypes identified worldwide in order to facilitate its use in resource-poor areas of the world with inadequate antibiotic availability. If available, such a vaccine can serve as an effective supplement to current guidelines of antibiotic prophylaxis against GBS in peripartum women and their neonates.