Neutralizing and binding antibody responses to SARS-CoV-2 with hybrid immunity in pregnancy.

Hybrid immunity against SARS-CoV-2 has not been well studied in pregnancy. We conducted a comprehensive analysis of neutralizing antibodies (nAb) and binding antibodies in pregnant individuals who received mRNA vaccination, natural infection, or both. A third vaccine dose augmented nAb levels compared to the two-dose regimen or natural infection alone; this effect was more pronounced in hybrid immunity.

Neutralizing antibody activity against SARS-CoV-2 variants in gestational age-matched mother-infant dyads after infection or vaccination.

Pregnancy confers unique immune responses to infection and vaccination across gestation. To date, there are limited data comparing vaccine- and infection-induced neutralizing Abs (nAbs) against COVID-19 variants in mothers during pregnancy. We analyzed paired maternal and cord plasma samples from 60 pregnant individuals.

Passive and active immunity in infants born to mothers with SARS-CoV-2 infection during pregnancy: prospective cohort study.

Objective: To investigate maternal immunoglobulins' (IgM, IgG) response to SARS-CoV-2 infection during pregnancy and IgG transplacental transfer, to characterise neonatal antibody response to SARS-CoV-2 infection, and to longitudinally follow actively and passively acquired antibodies in infants.

Design: A prospective observational study.

Setting: Public healthcare system in Santa Clara County (California, USA).