{
  "abstract": "Maternal IgG against group B streptococcus (GBS) capsular polysaccharide (CPS), is the principal placental mediator of neonatal protection, yet naturally acquired anti-CPS immunity has not been characterized in North African populations. To address this gap, we conducted a prospective study in a Moroccan mother-newborn cohort to quantify the serotype-specific anti-CPS IgG levels in relation to colonizing versus invasive GBS serotypes. Additionally, we assessed the transplacental transfer of anti-CPS IgG and identified potential correlates of invasive disease. We examined serotype-specific anti-CPS IgG (serotypes Ia-V) in the plasma from maternal and cord blood of 103 GBS-colonized pregnant women, 35 uncolonized controls and their paired newborns (90 paired colonized dyads, including five newborns with invasive GBS disease) using a standardized six-plex immunoassay. Transfer ratios were compared with 1.0 and cord concentrations with published serotype- and onset-specific risk-reduction thresholds. Maternal anti-CPS IgG concentrations varied by serotype, with the highest median for serotype II(1.36g/mL) and the lowest for serotype Ib(0.003g/mL). They were higher in GBS-colonized than uncolonized mothers for serotypes Ia, Ib and II. Maternal and cord blood IgG concentrations were correlated across serotypes, but placental transfer was incomplete, with median ratios of 0.50-0.80. Among 77 newborns, 13.0%(n=10) reached early-onset and 44.2%(n=34) achieved late-onset disease risk-reduction thresholds. The serotype IV was the most identified among neonatal infection disease cases, and this was associated with sub-protective anti-serotype IV antibody. This suggests that while naturally acquired anti-serotype II antibodies were predominant, the low level of anti-serotype IV antibodies could contribute to neonatal infection diseases in mother-newborn pairs.",
  "abstract_shown": true,
  "affiliations": [
    "Universite Libre de Bruxelles"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "N. Amar"
    },
    {
      "name": "T. Hall"
    },
    {
      "name": "E. Bentley"
    },
    {
      "name": "A. Chakroun"
    },
    {
      "name": "H. Ben-Taleb"
    },
    {
      "name": "R. Saïle"
    },
    {
      "name": "K. Le Doare"
    },
    {
      "affs": [
        0
      ],
      "name": "M. Chamekh"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/17b6e3bg9hp66.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.02.763839",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.11.02.763839v1.full",
  "id": "17b6e3bg9hp66",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.11.02.763839v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "immunology"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.11.02.763839v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/17b6e3bg9hp66.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T00:21:37Z",
      "native_id": "10.64898/2026.11.02.763839",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.11.02.763839v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:immunology",
      "subfield": "immunology"
    }
  ],
  "title": "Serotype specific anti-capsular polysaccharide IgG associated with colonizing and invasive group B streptococcus in pregnant woman-newborn dyads",
  "title_text": "Serotype specific anti-capsular polysaccharide IgG associated with colonizing and invasive group B streptococcus in pregnant woman-newborn dyads",
  "type": "preprint",
  "updated_at": "2026-11-05T00:21:06Z",
  "url": "https://research.draconitic.com/paper/17b6e3bg9hp66",
  "venue": "bioRxiv",
  "versions": []
}