Short summary

Part 1: To validate the correlation between quantitative amount of GBS-antibodies measured in dried blood spot samples (DBSS), umbillical cord blood and neonatal capillary blood.

Part 2: A case-control study to establish a serological marker of protection (quantitative GBS-IgGmeasured in DBSS) against invasive GBS-disease.

Rationale

Background: GBS infections are a major cause of invasive disease in neonates and infants causing sepsis, meningitis and thereby increased mortality.

A serolical marker of protection (quantitative GBS-IgGmeasured in DBSS) against invasive GBS-disease could facilitate the introduction and licensure of vaccines against GBS for maternal immunization during pregnancy in addition to ongoing clinical vaccine-studies.

Aim: Part 1: Our aim is to show, that DBSS can be used to measure quantitative amount of GBS-IgG as a surrogate for the maternal derived level. We will investigate this by estaming the correlation between quantitative GBS- IgG in DBSS, umbillical cord blood and neonatal capillary blood.

Part 2: With this case-control study we aim to measure the quantitative amount of GBS-IgG in DBSS in cases (neonates and infants with GBS-disease) and controls (healthy neonates) to establish a serological marker of protection against GBS-disease.

Description of the cohort

Part 1: 100 dyads of mothers-neonates will be included from the Maternity Ward in Sygehus Lillebaelt, Kolding.

Part 2: Cases: Neonates and infants below 1 year of age with GBS-infection born in Denmark from 2000-2022.

Controls: Healhty newborns from 2000-2022 mathched on sex, gestational age, birthweight and place of birth.

Data and biological material

Part 1: Mothers: Recto-vaginal swab and umbillical cord blood at the time of birth. Neonates: Extra DBSS and capillary blood sample from heel.

Part 2: DBSS from the Danish National Bank from cases and controls.

Collaborating researchers and departments

1) Department of Clinical Microbiology, Vejle Hospital, Jens Kjølseth Møller and Stine Yde Nielsen; 2) Department of Biomedicine, Aarhus University, Stine Yde Nielsen; 3) Department of Obstetrics, Kolding Hospital, Mohammed Khalil; 4) Department of Clinical Medicine, Aarhus University and 5) Department of Pediatrics and Adolescent Medicine, Aarhus University Hospital, Tine Brink Henriksen; 6) Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark, Hans Christian Sloved; 7) MinervaX, Per Fischer and Bengt Lindbom