Longitudinal Evaluation of Antibody Persistence in Mother-Infant Dyads After Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Pregnancy

Background There are limited data on how coronavirus disease 2019 (COVID-19) severity, timing of infection, and subsequent vaccination impact transplacental transfer and persistence of maternal and infant antibodies. Methods In a longitudinal cohort of pregnant women with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, maternal/infant sera were collected at enrollment, delivery/birth, and 6 months. Anti-SARS-CoV-2 spike immunoglobulin (Ig)G, IgM, and IgA were measured by enzyme-linked immunosorbent assay. Results Two-hundred fifty-six pregnant women and 135 infants were enrolled; 148 maternal and 122 neonatal specimens were collected at delivery/birth; 45 maternal and 48 infant specimens were collected at 6 months. Sixty-eight percent of women produced all anti-SARS-CoV-2 isotypes at delivery (IgG, IgM, IgA); 96% had at least 1 isotype. Symptomatic disease and vaccination before delivery were associated with higher maternal IgG at labor and delivery. Detectable IgG in infants dropped from 78% at birth to 52% at 6 months. In the multivariate analysis evaluating factors associated with detectable IgG in infants at delivery, significant predictors were 3rd trimester infection (odds ratio [OR] = 4.0), mild/moderate disease (OR = 4.8), severe/critical disease (OR = 6.3), and maternal vaccination before delivery (OR = 18.8). No factors were significant in the multivariate analysis at 6 months postpartum. Conclusions Vaccination in pregnancy post-COVID-19 recovery is a strategy for boosting antibodies in mother-infant dyads. In a longitudinal cohort of 256 pregnant women with COVID-19, maternal/infant sera were collected up to 6 months postpartum. Predelivery vaccination was highly predictive of infant IgG at birth. No factors were significant in the multivariate analysis at 6 months.