PATH’s Center for Vaccine Innovation and Access

Group B Streptococcus

Groundbreaking vaccine development to save newborn lives

Photo: PATH/Gabe Bienczycki

Photo: PATH/Gabe Bienczycki

Group B Streptococcus (GBS) is a leading cause of sepsis and meningitis in young infants worldwide—often affecting babies just a few hours old. Although people of all ages can contract the bacterial infection (caused by Streptococcus agalactiae), infants under three months of age are at highest risk for severe complications and death. Babies that survive GBS infections are often left with lifelong disabilities such as deafness, blindness, and developmental delays. GBS may also play a role in miscarriage and stillbirth.

Infants often inherit GBS as they enter the world. One in four women carry the GBS bacterium in their vagina or rectum, creating an opportunity for the disease to pass from an infected mother to her child during labor and birth. In some high-resource countries, women that test positive for carrying the GBS bacterium at 35 to 37 weeks of pregnancy receive intravenous antibiotics during labor, drastically reducing the chances of GBS passing to the newborn and causing early-onset disease. In low-resource countries, however, GBS screenings are all too often unavailable for women, which means that they are unlikely to be identified for preventive antibiotic treatment during labor. Moreover, babies born healthy can contract the disease in the weeks or months following birth without any clear cause—cases where maternal antibiotic prevention is of little help.

A vaccine against GBS delivered to pregnant women could eliminate the chance of newborn infection and provide babies with critical protection through infancy. No licensed vaccines currently exist to shield against GBS, creating a distinct vulnerability in parts of the world where early testing and preventive antibiotic treatment are not readily feasible. To bridge this gap, we are working to accelerate the development of a safe, effective, and affordable vaccine against GBS.

A maternal immunization strategy

PATH, in partnership with The Biovac Institute and Inventprise, is in early-stage development of a polyvalent, conjugate vaccine protecting against the most common kinds (or serotypes) of GBS. By vaccinating a woman during pregnancy, it is possible to boost her immunity against the bacterium and transfer protective antibodies through the placenta to her developing baby. The goal for the vaccine is to ultimately help reduce neonatal sepsis and meningitis in Africa and other low-income regions.

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