ABSTRACT
Importance: Antenatal care provides unique opportunities to assess SARS-CoV-2 seroprevalence and antibody response duration after natural infection detected during pregnancy; transplacental antibody transfer may inform peripartum and neonatal protection. Objective: Estimate seroprevalence and durability of antibodies from natural infection (anti-nucleocapsid (anti-N) IgG) among pregnant people, and evaluate transplacental transfer efficiency. Design: Seroprevalence study: cross-sectional SARS-CoV-2 antibody screening among pregnant people December 9, 2020-June 19, 2021. Cohort study: Pregnant people screened anti-N IgG+ by Abbott Architect chemiluminescent immunoassay in seroprevalence study or identified through medical records with RT-PCR+ or antigen positive results enrolled in a prospective cohort December 9, 2020-June 30, 2022 to longitudinally measure anti-N IgG responses. We collected cord blood and assessed transplacental transfer of maternally-derived anti-N antibodies. Setting: Three hospitals and 14 affiliated clinics providing antenatal and delivery care, Seattle, Washington metropolitan area. Participants: Seroprevalence study: pregnant people were screened for SAR-CoV-2 anti-N IgG during routine care. Cohort study: Pregnant people with evidence of prior SARS-CoV-2 infection (screened anti-N IgG+ from seroprevalence study or identified with a RT-PCR+ or antigen positive result from medical records) were enrolled in a cohort study to longitudinally measure anti-N IgG responses. Exposure(s) (for observational studies): COVID-19 diagnosis, symptoms, and disease severity. Main Outcome(s) and Measure(s): Presence and durability of SARS-CoV-2 anti-N IgG, transplacental transfer of maternally-derived anti-N IgG. Results: Of 1289 pregnant people screened in the seroprevalence study, 5% (65) tested SARS-CoV-2 anti-N IgG+, including 39 (60%) without prior RT-PCR+ or antigen positive results and 53 (82%) without symptoms. Among 89 participants enrolled in the cohort study, 73 (82%) had anti-N IgG+ results during pregnancy. Among 49 participants with delivery samples 33 (67%) were anti-N IgG negative by delivery. Of 24 remaining anti-N IgG+ at delivery with paired cord blood samples, 12 (50%) had efficient transplacental anti-N IgG antibody transfer. Median time from first anti-N IgG to below positive antibody threshold was 17 weeks and did not differ by prior RT-PCR+ or antigen positive status. Conclusions and Relevance: Maternally-derived SARS-CoV-2 antibodies to natural infection may wane before delivery. Vaccines are recommended for pregnant persons to reduce severe illness and confer protection to infants.
Subject(s)
COVID-19 , Critical IllnessABSTRACT
We compared the phenotype, diversity, and antigen specificity of T cells in the breastmilk and peripheral blood of lactating individuals who received SARS-CoV-2 mRNA vaccination. Relative to blood, breastmilk contained higher frequencies of T effector and central memory populations that expressed mucosal-homing markers. T cell receptor (TCR) sequence overlap was limited between blood and breastmilk. Overabundant breastmilk clones were observed in all individuals, were structurally diverse, and contained CDR3 sequences with known epitope specificity including to SARS-CoV-2 Spike. Spike-specific TCRs were more frequent in breastmilk compared to blood and expanded in breastmilk following a third mRNA vaccine dose. Our observations indicate that the lactating breast contains a distinct T cell population that can be modulated by maternal vaccination with potential implications for infant passive protection.
Subject(s)
Memory Disorders , Severe Acute Respiratory SyndromeABSTRACT
Background: The purpose of this study was to estimate prevalence of asymptomatic SARS-CoV-2 infection among patients admitted to obstetric inpatient units throughout the United States as detected by universal screening. We sought to describe the relationship between obstetric inpatient asymptomatic infection rates and publicly available surrounding community infection rates. Methods: This was a cross-sectional study in which medical centers reported rates of positive SARS-CoV-2 testing in asymptomatic pregnant and immediate postpartum patients over a 1-3 month time span in 2020. Publicly reported SARS-CoV-2 case rates from the relevant county and state for each center were collected from the COVID Act Now dashboard and the COVID Tracking Project for correlation analysis. Findings: Data were collected from nine health centers, encompassing 18 hospitals. Participating health centers were located in Alabama, California, Illinois, Louisiana, New Jersey, North Carolina, Pennsylvania, Rhode Island, Utah, and Washington State. Each hospital had an active policy for universal SARS-CoV-2 testing on obstetric inpatient unit. A total of 10,147 SARS-CoV-2 tests were administered, of which 124 were positive (1·2%). Positivity rates varied by site, ranging from 0-3·2%. While SARS-CoV-2 infection rates were lower in asymptomatic obstetric inpatient groups than the surrounding communities, there was a positive correlation between positivity rates in obstetric inpatient units and their surrounding county (p=·003, r=·782) and state (p=·007, r=·708). Interpretation: Given the correlation between community and obstetric inpatient rates, the necessity of SARS-CoV-2 related healthcare resource utilization in obstetric inpatient units may be best-informed by surrounding community infection rates. Funding Information: Internal funding was used.Declaration of Interests: None to declare. Ethics Approval Statement: The study was IRB approved or determined exempt at each center.