COVID-19 booster vaccination during pregnancy enhances maternal binding and neutralizing antibody responses and transplacental antibody transfer to the newborn.

The immune response to COVID-19 booster vaccinations during pregnancy for mothers and their newborns and the functional response of vaccine-induced antibodies against Omicron variants are not well characterized. We conducted a prospective, multicenter cohort study of participants vaccinated during pregnancy with primary or booster mRNA COVID-19 vaccines from July 2021 to January 2022 at 9 academic sites. We determined SARS-CoV-2 binding and live virus and pseudovirus neutralizing antibody (nAb) titers pre- and post-vaccination, and at delivery for both maternal and infant participants. Immune responses to ancestral and Omicron BA.1 SARS-CoV-2 strains were compared between primary and booster vaccine recipients in maternal sera at delivery and in cord blood, after adjusting for days since last vaccination. A total of 240 participants received either Pfizer or Moderna mRNA vaccine during pregnancy (primary 2-dose series: 167; booster dose: 73). Booster vaccination resulted in significantly higher binding and nAb titers, including to the Omicron BA.1 variant, in maternal serum at delivery and in cord blood compared to a primary 2-dose series (range 0.44-0.88 log10 higher, p < 0.0001 for all comparisons). Live virus nAb to Omicron BA.1 were present at delivery in 9 % (GMT ID50 12.7) of Pfizer and 22 % (GMT ID50 14.7) of Moderna primary series recipients, and in 73 % (GMT ID50 60.2) of mRNA boosted participants (p < 0.0001), although titers were significantly lower than to the D614G strain. Transplacental antibody transfer was efficient for all regimens with median transfer ratio range: 1.55-1.77 for IgG, 1.00-1.78 for live virus nAb and 1.79-2.36 for pseudovirus nAb. COVID-19 mRNA vaccination during pregnancy elicited robust immune responses in mothers and efficient transplacental antibody transfer to the newborn. A booster dose during pregnancy significantly increased maternal and cord blood binding and neutralizing antibody levels, including against Omicron BA.1. Findings support the use of a booster dose of COVID-19 vaccine during pregnancy.

Outcomes Following Extracorporeal Membrane Oxygenation for Severe COVID-19 in Pregnancy or Post Partum.

Importance: Existing reports of pregnant patients with COVID-19 disease who require extracorporeal membrane oxygenation (ECMO) are limited, with variable outcomes noted for the maternal-fetal dyad. Objective: To examine maternal and perinatal outcomes associated with ECMO used for COVID-19 with respiratory failure during pregnancy. Design, Setting, and Participants: This retrospective multicenter cohort study examined pregnant and postpartum patients who required ECMO for COVID-19 respiratory failure at 25 hospitals across the US. Eligible patients included individuals who received care at one of the study sites, were diagnosed with SARS-CoV-2 infection during pregnancy or up to 6 weeks post partum by positive nucleic acid or antigen test, and for whom ECMO was initiated for respiratory failure from March 1, 2020, to October 1, 2022. Exposures: ECMO in the setting of COVID-19 respiratory failure. Main outcome and measures: The primary outcome was maternal mortality. Secondary outcomes included serious maternal morbidity, obstetrical outcomes, and neonatal outcomes. Outcomes were compared by timing of infection during pregnancy or post partum, timing of ECMO initiation during pregnancy or post partum, and periods of circulation of SARS-CoV-2 variants. Results: From March 1, 2020, to October 1, 2022, 100 pregnant or postpartum individuals were started on ECMO (29 [29.0%] Hispanic, 25 [25.0%] non-Hispanic Black, 34 [34.0%] non-Hispanic White; mean [SD] age: 31.1 [5.5] years), including 47 (47.0%) during pregnancy, 21 (21.0%) within 24 hours post partum, and 32 (32.0%) between 24 hours and 6 weeks post partum; 79 (79.0%) had obesity, 61 (61.0%) had public or no insurance, and 67 (67.0%) did not have an immunocompromising condition. The median (IQR) ECMO run was 20 (9-49) days. There were 16 maternal deaths (16.0%; 95% CI, 8.2%-23.8%) in the study cohort, and 76 patients (76.0%; 95% CI, 58.9%-93.1%) had 1 or more serious maternal morbidity events. The largest serious maternal morbidity was venous thromboembolism and occurred in 39 patients (39.0%), which was similar across ECMO timing (40.4% pregnant [19 of 47] vs 38.1% [8 of 21] immediately postpartum vs 37.5% postpartum [12 of 32]; P > .99). Conclusions and Relevance: In this multicenter US cohort study of pregnant and postpartum patients who required ECMO for COVID-19-associated respiratory failure, most survived but experienced a high frequency of serious maternal morbidity.

Placental Injury and Antibody Transfer Following COVID-19 Disease in Pregnancy.

We examined the relationship between placental histopathology and transplacental antibody transfer in pregnant patients following SARS-CoV-2 infection. Differences in plasma concentrations of anti-Receptor Biding Domain (RBD) Immunoglobulin (Ig) G antibodies in maternal and cord blood were analyzed according to presence of placental injury. Median [IQR] anti-RBD IgG concentrations in cord blood with placental injury (n = 7) did not differ significantly from those without injury (n= 16) [(2.7 [1.8,3.6] vs 2.7[2.4, 2.9], p= 0.59). However, they were associated with lower transfer ratios (median [IQR] 0.77[0.61, 0.97] vs. 0.97[0.80, 1.01], p = 0.05) suggesting that SARS-CoV-2 placental injury mediates reduced maternal-fetal antibody transfer.

Antibody response, neutralizing potency, and transplacental antibody transfer following SARS-CoV-2 infection versus mRNA-1273, BNT162b2 COVID-19 vaccination in pregnancy.

OBJECTIVE: To improve our understanding of the immune response, including the neutralization antibody response, following COVID-19 vaccination in pregnancy. METHODS: This was a prospective cohort study comprising patients with PCR-confirmed SARS-CoV-2 infection and patients who received both doses of mRNA COVID-19 vaccine (mRNA-1273, BNT162b2) in pregnancy recruited from two hospitals in Atlanta, GA, USA. Maternal blood and cord blood at delivery were assayed for anti-receptor binding domain (RBD) IgG, IgA and IgM, and neutralizing antibody. The detection of antibodies, titers, and maternal to fetal transfer ratios were compared. RESULTS: Nearly all patients had detectable RBD-binding IgG in maternal and cord samples. The vaccinated versus infected cohort had a significantly greater proportion of cord samples with detectable neutralizing antibody (94% vs. 28%, P < 0.001) and significantly higher transfer ratios for RBD-specific IgG and neutralizing antibodies with a transfer efficiency of 105% (vs. 80%, P < 0.001) and 110% (vs. 90%, P < 0.001), respectively. There was a significant linear decline in maternal and cord blood RBD-specific IgG and neutralizing antibody titers as time from vaccination to delivery increased. CONCLUSIONS: Those who receive the mRNA COVID-19 vaccine mount an immune response that is equivalent to-if not greater than-those naturally infected by SARS-CoV-2 during pregnancy.

Covid-19 vaccination in pregnancy.

Pregnancy is an independent risk factor for severe covid-19. Vaccination is the best way to reduce the risk for SARS-CoV-2 infection and limit its morbidity and mortality. The current recommendations from the World Health Organization, Centers for Disease Control and Prevention, and professional organizations are for pregnant, postpartum, and lactating women to receive covid-19 vaccination. Pregnancy specific considerations involve potential effects of vaccination on fetal development, placental transfer of antibodies, and safety of maternal vaccination. Although pregnancy was an exclusion criterion in initial clinical trials of covid-19 vaccines, observational data have been rapidly accumulating and thus far confirm that the benefits of vaccination outweigh the potential risks. This review examines the evidence supporting the effectiveness, immunogenicity, placental transfer, side effects, and perinatal outcomes of maternal covid-19 vaccination. Additionally, it describes factors associated with vaccine hesitancy in pregnancy. Overall, studies monitoring people who have received covid-19 vaccines during pregnancy have not identified any pregnancy specific safety concerns. Additional information on non-mRNA vaccines, vaccination early in pregnancy, and longer term outcomes in infants are needed. To collect this information, vaccination during pregnancy must be prioritized in vaccine research.

Outcomes of pregnant patients treated with REGEN-COV during the COVID-19 pandemic.

BACKGROUND: Pregnant patients with SARS-CoV-2 infection are at increased risk for severe disease including hospitalization, intensive care admission, ventilatory support, and death. Although pregnant patients were excluded from investigational trials for pharmacologic treatments for COVID-19 illness, the National Institutes of Health treatment guidelines state that efficacious treatments should not be withheld from pregnant patients. An infusion of casirivimab and imdevimab (REGEN-COV), a monoclonal antibody therapy, was shown to reduce the risk of COVID-19-related hospitalization or death from any cause and resolved symptoms and reduced SARS-CoV-2 viral load more rapidly than placebo. In July of 2021, the Food and Drug Administration released an Emergency Use Authorization for REGEN-COV. Although pregnant persons were not included in the original trials, given the higher risk of morbidity and mortality in the pregnant population, our institution offered REGEN-COV to our pregnant patients beginning in August of 2021. Side effects after REGEN-COV administration are rare and thought to be secondary to COVID-19 rather than REGEN-COV. OBJECTIVE: This study aimed to track safety and clinical outcomes in unvaccinated pregnant patients who received REGEN-COV and to compare these outcomes with those of a contemporary cohort of patients who tested positive for SARS-CoV-2 and were eligible but did not receive REGEN-COV. Our hypothesis was that REGEN-COV administration during pregnancy is safe, and that pregnant persons who received REGEN-COV would experience less severe COVID-19 respiratory illness, with decreased length of hospital stay, rates of intensive care unit admission, and need for oxygen and other COVID-19 therapeutics. STUDY DESIGN: This is a retrospective cohort study of pregnant patients who either tested positive for SARS-CoV-2 or had a known exposure to a COVID-19-positive person, and were therefore eligible for REGEN-COV at our institution. Within this cohort, we compared those who received REGEN-COV with those who did not between March and October of 2021 at Grady Memorial Hospital in Atlanta, Georgia. The main outcomes studied were perinatal outcomes, safety data, and the clinical course of SARS-CoV-2 infection. RESULTS: From March to October of 2021, 86 pregnant people tested positive for SARS-CoV-2 via real-time polymerase chain reaction or had a confirmed exposure. In this group, 36 received REGEN-COV and 50 did not. There were no instances of infusion rate adjustment or discontinuation, anaphylaxis, or death among individuals who received REGEN-COV. One individual experienced worsening shortness of breath >24 hours after administration, which was classified as an infusion-related reaction. There were no significant differences in perinatal outcomes, length of hospitalization, rates of intensive care unit admission, additional pharmacologic treatment for COVID-19, or oxygen requirement between the 2 groups. CONCLUSION: Administration of REGEN-COV is safe in pregnancy and did not increase adverse maternal, neonatal, or obstetrical outcomes. There was not a statistically significant difference in COVID-19-related outcomes in our high-risk population. Given the likely safety of this drug in pregnancy and its known benefits in the nonpregnant population, we advocate for the continued use of this therapy and encourage the development of future studies to enroll a larger and more diverse cohort to explore its efficacy further.

Maternal Antibody Response, Neutralizing Potency, and Placental Antibody Transfer After Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection.

OBJECTIVE: To characterize maternal immune response after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy and quantify the efficiency of transplacental antibody transfer. METHODS: We conducted a prospective cohort study of pregnant patients who tested positive for SARS CoV-2 infection at any point in pregnancy and collected paired maternal and cord blood samples at the time of delivery. An enzyme-linked immunosorbent assay (ELISA) and neutralization assays were performed to measure maternal plasma and cord blood concentrations and neutralizing potency of immunoglobulin (Ig)G, IgA, and IgM antibodies directed against the SARS-CoV-2 spike protein. Differences in concentrations according to symptomatic compared with asymptomatic infection and time from positive polymerase chain reaction (PCR) test result to delivery were analyzed using nonparametric tests of significance. The ratio of cord to maternal anti-receptor-binding domain IgG titers was analyzed to assess transplacental transfer efficiency. RESULTS: Thirty-two paired samples were analyzed. Detectable anti-receptor-binding domain IgG was detected in 100% (n=32) of maternal and 91% (n=29) of cord blood samples. Functional neutralizing antibody was present in 94% (n=30) of the maternal and 25% (n=8) of cord blood samples. Symptomatic infection was associated with a significant difference in median (interquartile range) maternal anti-receptor-binding domain IgG titers compared with asymptomatic infection (log 3.2 [3.5-2.4] vs log 2.7 [2.9-1.4], P=.03). Median (interquartile range) maternal anti-receptor-binding domain IgG titers were not significantly higher in patients who delivered more than 14 days after a positive PCR test result compared with those who delivered within 14 days (log 3.3 [3.5-2.4] vs log 2.67 [2.8-1.6], P=.05). Median (range) cord/maternal antibody ratio was 0.81 (0.67-0.88). CONCLUSIONS: These results demonstrate robust maternal neutralizing and anti-receptor-binding domain IgG response after SARS-CoV-2 infection, yet a lower-than-expected efficiency of transplacental antibody transfer and a significant reduction in neutralization between maternal blood and cord blood. Maternal infection does confer some degree of neonatal antibody protection, but the robustness and durability of protection require further study.

Sociodemographic Predictors of SARS-CoV-2 Infection in Obstetric Patients, Georgia, USA.

We conducted a cohort study to determine sociodemographic risk factors for severe acute respiratory syndrome coronavirus 2 infection among obstetric patients in 2 urban hospitals in Atlanta, Georgia, USA. Prevalence of infection was highest among women who were Hispanic, were uninsured, or lived in high-density neighborhoods.