# Infant Immunity

> **NIH NIH U19** · UNIVERSITY OF MARYLAND BALTIMORE · 2022 · $414,436

## Abstract

PROJECT 3 – ABSTRACT
Antibodies transferred from the mother to the fetus are a central determinant of immunity during the first months
of life. They provide protection against infectious pathogens when the magnitude and avidity of infant antibody
responses are relatively low. On the other hand, maternal antibodies can decrease infant vaccine responses, a
phenomenon named vaccine interference. The mechanisms underlying antibody-dependent immunity against
pathogens and regulation of vaccine responses in early life remain poorly understood. This gap in knowledge
limits the rationale design of maternal immunization strategies providing optimal protection to young infants. The
overall aim of the project is to identify key biophysical (subclass and glycosylation profile) and functional features
(activation of innate immune effectors) of transferred maternal antibodies mediating pathogen control and
regulating vaccine responses in young infants. The project is focused on the two model pathogens selected for
the whole program, pertussis and influenza. A systems serology approach will be used to characterize the
functional properties of maternal antibodies transferred to the newborn following immunization during pregnancy
and the impact of maternal immunization on the quality of infant vaccine responses. Engineering of human
antibodies and adoptive transfer to genetically deficient and humanized mice will be used to determine the role
of specific biophysical features of transferred maternal antibodies and of their interactions with infant IgG Fc
receptors and complement in the control of pathogens and in the regulation of vaccine responses. Synergizing
with Projects 1 and 2, Project 3 will provide mechanistic insight in the functional implications of the regulation of
vaccine responses by pregnancy, the selective transfer of maternal antibodies across the placenta and their
decay after birth for immunity to pathogens in infancy. Synergizing with project 4, project 3 will define the
functional implications of the interactions between transferred maternal antibodies and the infant immune system
for vaccine responses in infancy. The knowledge gained through the project will provide unprecedented insight
in the immunobiology of maternal and infant immunization and will inform the development of vaccines and
monoclonal antibodies providing optimal protection against infectious diseases in early life.

## Key facts

- **NIH application ID:** 10449296
- **Project number:** 5U19AI145825-02
- **Recipient organization:** UNIVERSITY OF MARYLAND BALTIMORE
- **Principal Investigator:** Arnaud Marchant
- **Activity code:** U19 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $414,436
- **Award type:** 5
- **Project period:** 2021-07-12 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10449296

## Citation

> US National Institutes of Health, RePORTER application 10449296, Infant Immunity (5U19AI145825-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10449296. Licensed CC0.

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