Invasive Group B Streptococcus Disease Clinical Trial
Official title:
Establishing a Sero-correlate of Protection Against Invasive Group B Streptococcus Disease in Newborns and Young Infants Aged <=90 Days
Compare anticapsular antibody levels against Group B Streptococcus at delivery in mothers and their infants who develop disease versus those who do not. Use this comparison to establish antibody levels associated with reductions in risk of GBS disease in infants aged less than 90 days.
Group B Streptococcus (GBS) is a leading cause of invasive disease during the neonatal period
in developed and developing countries. The global incidence of disease is 0.53 per 1000 live
births, though a substantially higher incidence has been reported from South Africa (3 per
1000 live births). Of the disease-causing serotypes, types Ia and III account for over 70% of
invasive disease in young infants. The introduction of screening for maternal rectovaginal
GBS colonization, with subsequent treatment of colonized women with intrapartum antibiotic
prophylaxis (IAP) at delivery, has led to a >80% reduction in the incidence of disease in
some settings (Schrag, 2012). However, the residual burden of early-onset disease (EOD) in
countries which have implemented universal screening and IAP remains similar to the incidence
of late-onset disease (LOD), which has not declined over time. The resources necessary to
implement a screening and IAP program has limited the establishment of this intervention in
other developed and most developing countries.
GBS capsular polysaccharide-protein conjugate vaccines (GBS-CV) aimed at the immunization of
pregnant women, with protection of the newborn expected from trans-placental acquisition of
the induced antibodies in utero have been developed.
There are a number of challenges to undertaking a large efficacy trial of GBS-CV aimed at
licensure of this vaccine. Consequently, licensure of GBS-CV may depend on establishing an
immunologic/serologic correlate of protection against invasive disease in newborns, as has
been successfully motivated for and adopted in the licensure pathway of meningococcal
vaccines. Although previous studies have aimed to identify serotype-specific correlates of
anticapsular antibody protection against invasive GBS disease during early-infancy;
differences in study-design, age-range of invasive-cases, antibody assay methods and a lack
of standardized reference serum between tests mean a robust sero-correlate of protection
against GBS has yet to be identified.
We propose to conduct a case control study nested within a prospective, longitudinal cohort
of mothers and their infants <=90 days of age, at one academic hospital center in South
Africa. The limited intrapartum antibiotic exposure (10-12% deliveries), relatively high
incidence of both EOD and LOD (2 per 1000 live births and 1 per 1000 live births
respectively) and standardized laboratory surveillance (for case identification) offers an
optimal setting in which to establish correlates of protection against the GBS serotypes that
predominate in this setting (serotypes Ia and III for EOD and serotype III for LOD).
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| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Withdrawn |
NCT02099149 -
Antibody Levels Associated With Reduced Risk of Invasive Group B Streptococcus Disease in Infants Aged Less Than 90 Days
|
N/A |