Compromised SARS-CoV-2-specific placental antibody transfer.

Area of Science:

• Immunology
• Maternal-fetal medicine
• Virology

Background:

• Pregnant women experience more severe SARS-CoV-2 disease.
• The impact of maternal SARS-CoV-2 infection on infant immunity transfer is unclear.
• Maternal infections can compromise placental antibody transfer, but mechanisms are unknown.

Purpose of the Study:

• To investigate SARS-CoV-2-specific antibody transfer across the placenta.
• To characterize the Fc profile of transferred antibodies.
• To understand mechanisms affecting antibody transfer during pregnancy.

Main Methods:

• Systems serology was employed to analyze antibody profiles.
• Antibodies specific to influenza, pertussis, and SARS-CoV-2 were studied.
• Placental transfer and functional activity of antibodies were assessed.

Main Results:

• Influenza- and pertussis-specific antibodies transferred efficiently.
• SARS-CoV-2-specific antibody transfer was significantly reduced, especially in third-trimester infections.
• Reduced transfer was linked to altered antibody glycosylation and partially compensated by increased IgG and placental FCGR3A expression.

Conclusions:

• Maternal SARS-CoV-2 infection impairs antibody transfer to neonates.
• Altered antibody glycosylation and placental factors influence transfer efficiency.
• Findings suggest compensatory mechanisms and inform maternal vaccine strategies.