Abstract
Background: SARS-CoV-2 infection during early infancy can result in severe disease. We evaluated the durability of maternally-derived anti-SARS-CoV-2 antibodies in infants and its relation to antenatal vaccination timing. Methods: Sera were prospectively collected at birth and 3 months after delivery from mother-infant pairs following antenatal BNT162b2 vaccination. SARS-CoV-2 receptor binding domain (RBD)-specific IgG levels and neutralizing activity were evaluated. Results: 56 mother-infant pairs were included: 15 (26.8%) were vaccinated in the first trimester, 16 (28.6%) in the second trimester, and 25 (44.6%) in the third trimester. At the time of delivery, all neonates were positive for anti-RBD-specific IgG with a median concentration of 4046 [IQR 2446-7896] AU/mL, with the highest concentration found after third trimester vaccination (median 6763 [IQR 3857-12561] AU/mL). At 3 months after delivery, anti RBD-specific IgG levels in infants significantly waned with a median concentration of 545 [IQR 344-810] AU/mL (P <. 001). The half-life of anti-RBD-specific IgG was 66 days among mothers and 30 days among infants. While at the time of delivery, all neonates had detectable neutralizing activity regardless of gestational age at vaccination, at 3-months of age, a higher proportion of infants born to mothers vaccinated in third trimester had persistent neutralizing activity as compared to those born to mothers vaccinated in second trimester. Conclusions: Maternal vaccination leads to efficient transplacental antibody transfer, with persistent anti-SARS-CoV-2 antibodies detected at 3 months of age in all infants. The observed effect of antenatal immunization timing on the kinetics of maternally-derived antibodies may have implications for SARS-CoV-2 vaccination strategies.
Original language | English |
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Pages (from-to) | E274-E279 |
Journal | Clinical Infectious Diseases |
Volume | 76 |
Issue number | 3 |
DOIs | |
State | Published - 1 Feb 2023 |
Bibliographical note
Publisher Copyright:© 2022 The Author(s). Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved.
Keywords
- COVID-19
- infants
- passive immunity
- pregnancy
- vaccination
- Humans
- Vaccination
- Immunoglobulin G
- Infant
- Antibodies, Viral
- Mothers
- Pregnancy
- BNT162 Vaccine
- SARS-CoV-2
- COVID-19 Vaccines
- Female
- COVID-19/prevention & control
- Infant, Newborn
ASJC Scopus subject areas
- Microbiology (medical)
- Infectious Diseases