Ziyaad Dangor1, Gaurav Kwatra2, Alane Izu2, Peter Adrian2, Clare L Cutland2, Sithembiso Velaphi3, Daynia Ballot3, Gary Reubenson3, Elizabeth R Zell4, Sanjay G Lala3, Shabir A Madhi5. 1. Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, South Africa; Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, South Africa. 2. Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, South Africa. 3. Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, South Africa. 4. Stat-Epi Associates Inc., FL, USA. 5. Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, South Africa; National Institute for Communicable Diseases: A Division of National Health Laboratory Service, South Africa. Electronic address: madhis@rmpru.co.za.
Abstract
BACKGROUND: Vaccinating pregnant women may prevent invasive Group B Streptococcus (GBS) disease in their young infants. In a low-middle income setting, we sought to determine an association between natural maternal antibody responses and the development of invasive GBS disease. METHODS: We undertook a matched case-control study in Johannesburg, South Africa. Maternal and infant antibody concentrations were compared between serotype-specific Ia and III GBS cases and well-baby controls in which the mother was colonized with the same serotype. RESULTS: The median maternal serotype Ia and III antibody concentrations (in μg/mL) were 0.05 (IQR: 0.02-0.24; n=27) and 0.14 (IQR: 0.08-0.33; n=29) in cases, and 0.29 (IQR: 0.06-1.60; n=43) and 0.29 (IQR: 0.13-0.58; n=31) in homotypic controls, respectively. A smaller proportion of cases as compared to homotypic controls had higher serotype Ia and III maternal antibody concentrations. Using Bayesian modeling, we demonstrated that the risk of invasive GBS disease was less than 10% with maternal antibody concentrations ≥ 6 μg/mL and ≥ 3 μg/mL for serotypes Ia and III, respectively. CONCLUSIONS: Maternal capsular antibody concentrations are associated with the risk of invasive GBS disease in infants. In a low-middle income setting with a high burden of invasive disease, we have demonstrated a sero-correlate of protection for GBS serotypes Ia and III which could facilitate vaccine licensure.
BACKGROUND: Vaccinating pregnant women may prevent invasive Group B Streptococcus (GBS) disease in their young infants. In a low-middle income setting, we sought to determine an association between natural maternal antibody responses and the development of invasive GBS disease. METHODS: We undertook a matched case-control study in Johannesburg, South Africa. Maternal and infant antibody concentrations were compared between serotype-specific Ia and III GBS cases and well-baby controls in which the mother was colonized with the same serotype. RESULTS: The median maternal serotype Ia and III antibody concentrations (in μg/mL) were 0.05 (IQR: 0.02-0.24; n=27) and 0.14 (IQR: 0.08-0.33; n=29) in cases, and 0.29 (IQR: 0.06-1.60; n=43) and 0.29 (IQR: 0.13-0.58; n=31) in homotypic controls, respectively. A smaller proportion of cases as compared to homotypic controls had higher serotype Ia and III maternal antibody concentrations. Using Bayesian modeling, we demonstrated that the risk of invasive GBS disease was less than 10% with maternal antibody concentrations ≥ 6 μg/mL and ≥ 3 μg/mL for serotypes Ia and III, respectively. CONCLUSIONS: Maternal capsular antibody concentrations are associated with the risk of invasive GBS disease in infants. In a low-middle income setting with a high burden of invasive disease, we have demonstrated a sero-correlate of protection for GBS serotypes Ia and III which could facilitate vaccine licensure.
Authors: Han Wool Kim; Ji Hyen Lee; Hye Kyung Cho; Hyunju Lee; Ho Seong Seo; Soyoung Lee; Kyung Hyo Kim Journal: J Korean Med Sci Date: 2017-05 Impact factor: 2.153
Authors: Johan Vekemans; Jonathan Crofts; Carol J Baker; David Goldblatt; Paul T Heath; Shabir A Madhi; Kirsty Le Doare; Nick Andrews; Andrew J Pollard; Samir K Saha; Stephanie J Schrag; Peter G Smith; David C Kaslow Journal: Vaccine Date: 2019-04-25 Impact factor: 3.641
Authors: Kirsty Le Doare; Paul T Heath; Jane Plumb; Natalie A Owen; Peter Brocklehurst; Lucy C Chappell Journal: Clin Infect Dis Date: 2019-08-01 Impact factor: 9.079