Anti-Spike Antibodies Present in the Milk of SARS-CoV-2 Vaccinated Mothers Are Complement-Activating

Chiara Agostinis, Miriam Toffoli, Andrea Balduit, Alessandro Mangogna, Hadida Yasmin, Chiara Ragazzon, Silvia Pegoraro, Giuseppina Campisciano, Guglielmo Stabile, Gabriella Zito, Uday Kishore, Manola Comar, Federica Scrimin, Roberta Bulla, Giuseppe Ricci

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Although only 0.8–1% of SARS-CoV-2 infections are in the 0–9 age-group, pneumonia is still the leading cause of infant mortality globally. Antibodies specifically directed against SARS-CoV-2 spike protein (S) are produced during severe COVID-19 manifestations. Following vaccination, specific antibodies are also detected in the milk of breastfeeding mothers. Since antibody binding to viral antigens can trigger activation of the complement classical - pathway, we investigated antibody-dependent complement activation by anti-S immunoglobulins (Igs) present in breast milk following SARS-CoV-2 vaccination. This was in view of the fact that complement could play a fundamentally protective role against SARS-CoV-2 infection in newborns. Thus, 22 vaccinated, lactating healthcare and school workers were enrolled, and a sample of serum and milk was collected from each woman. We first tested for the presence of anti-S IgG and IgA in serum and milk of breastfeeding women by ELISA. We then measured the concentration of the first subcomponents of the three complement pathways (i.e., C1q, MBL, and C3) and the ability of anti-S Igs detected in milk to activate the complement in vitro. The current study demonstrated that vaccinated mothers have anti-S IgG in serum as well as in breast milk, which is capable of activating complement and may confer a protective benefit to breastfed newborns.

Original languageEnglish
Article number4395
JournalInternational journal of molecular sciences
Volume24
Issue number5
DOIs
Publication statusPublished - Mar 2023

Keywords

  • antibodies
  • breast milk
  • classical pathway
  • complement system
  • COVID-19 vaccines

ASJC Scopus subject areas

  • Catalysis
  • Molecular Biology
  • Spectroscopy
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

Fingerprint

Dive into the research topics of 'Anti-Spike Antibodies Present in the Milk of SARS-CoV-2 Vaccinated Mothers Are Complement-Activating'. Together they form a unique fingerprint.

Cite this