Immunogenicity of COVID-19 mRNA Vaccines in Pregnant and Lactating Women

From Womb to World: Exploring the Immunological Connections between Mother and Child

Mother and child are immunologically interconnected by mechanisms that we are only beginning to understand. During pregnancy, multiple molecular and cellular factors of maternal origin are transferred across the placenta and influence the development and function of the fetal and newborn immune system. Altered maternal immune states arising from pregnancy-associated infections or immunizations have the potential to program offspring immune function in ways that may have long-term health consequences. In this study, we review current literature on the impact of prenatal infection and vaccination on the developing immune system, highlight knowledge gaps, and look to the horizon to envision maternal interventions that could benefit both the mother and her child.

Systematic Review: Safety and Efficacy of mRNA COVID-19 Vaccines in Pregnant Women

Since pregnant women were excluded from clinical trials for vaccines against SARS-CoV-2, the novel coronavirus disease 2019 (COVID-19), there is limited data on the safety and efficacy of vaccines in this population. This systematic review explored the safety and efficacy of mRNA vaccines in pregnant women. A literature search was performed using Ovid databases through November 2021 for all studies evaluated efficacy and safety of mRNA COVID-19 vaccines in pregnant women. A total of five studies including 42,782 women were included in the systematic review. Humoral immunity to COVID-19 was detected in pregnant women who received the vaccine and no differences found in spike-specific T-cell responses. Incidence of high-grade chronic villitis is higher in the unvaccinated group with adjusted odds ratio of .31 (.1-.97), P < .05. Vaccination in pregnant women resulted in 12.6% spontaneous abortions (SAB) with 92.3% occurring in the first trimester, .1% stillbirth (>20 weeks gestation), 9.4% preterm birth (<37 weeks gestation), and 2.2% congenital abnormalities. The mRNA COVID-19 vaccines are immunogenic in pregnant women and no obvious safety concerns observed. There is no increased incidence of adverse reactions in pregnant women. Our finding supports that pregnant women should receive the vaccination at their earliest convenience regardless of trimester.

Temporal trends and characteristics associated with racial, ethnic, and sex representation in COVID-19 clinical trials: A systematic review and meta-analysis

BACKGROUND

Early in the pandemic, extensive attention was cast on limited inclusion of historically underrepresented patient populations in COVID-19 clinical trials. How diverse representation improved following these initial reports remains unclear.

METHODS

PubMed, Embase and the Cochrane Library were searched (through April 2024) for US-based COVID-19 trials. Utilizing random-effects, we compared expected proportions of trial participants from racial and ethnic groups and of female sex between trials enrolling primarily in 2020 versus primarily 2021-2022. Meta-regression was performed to assess associations between trial characteristics and group representation.

RESULTS

We retrieved 157 studies comprising 198,012 participants. White (2020: 63.1% [95% CI, 60.8%-67.3%]; 2021-2022: 73.8% [95% CI, 71.5%-76.0%]) and female representation (2020: 46.1% [95% CI, 44.7%-47.4%)]; 2021-2022: 51.1% [95% CI, 49.3%-52.8%) increased across enrollment periods. Industry-sponsored trials were associated with higher White (coefficient, 0.10 [95% CI, 0.03-0.18]) and Hispanic or Latinx representation (coefficient, 0.16 [95% CI, 0.08-0.25]) and lower Asian (coefficient, -0.03 [95% CI, -0.06- -0.003]) and female representation (coefficient, -0.03 [95% CI, -0.07- -0.002]). Outpatient trials were associated with higher White (coefficient, 0.20 [95% CI, 0.13-0.26]) and female representation (coefficient, 0.16 [95% CI, 0.13-0.18]), and lower Black representation (coefficient, -0.10 [95% CI, -0.10- -0.08]).

CONCLUSIONS

Despite improved female representation in COVID-19 trials over time, there was no clear increase in non-White representation. Trial characteristics such as primary sponsor, clinical setting, and intervention type correlate with representation of specific demographic groups and should be considered in future efforts to improve participant diversity.

A Significant Contribution of the Classical Pathway of Complement in SARS-CoV-2 Neutralization of Convalescent and Vaccinee Sera

Although high titers of neutralizing Abs in human serum are associated with protection from reinfection by SARS-CoV-2, there is considerable heterogeneity in human serum-neutralizing Abs against SARS-CoV-2 during convalescence between individuals. Standard human serum live virus neutralization assays require inactivation of serum/plasma prior to testing. In this study, we report that the SARS-CoV-2 neutralization titers of human convalescent sera were relatively consistent across all disease states except for severe COVID-19, which yielded significantly higher neutralization titers. Furthermore, we show that heat inactivation of human serum significantly lowered neutralization activity in a live virus SARS-CoV-2 neutralization assay. Heat inactivation of human convalescent serum was shown to inactivate complement proteins, and the contribution of complement in SARS-CoV-2 neutralization was often >50% of the neutralizing activity of human sera without heat inactivation and could account for neutralizing activity when standard titers were zero after heat inactivation. This effect was also observed in COVID-19 vaccinees and could be abolished in individuals who were undergoing treatment with therapeutic anti-complement Abs. Complement activity was mainly dependent on the classical pathway with little contributions from mannose-binding lectin and alternative pathways. Our study demonstrates the importance of the complement pathway in significantly increasing viral neutralization activity against SARS-CoV-2 in spike seropositive individuals.

The type of COVID-19 vaccination does not affect reproductive function and pregnancy outcomes in infertile couples

Introduction

Studies on the effect of vaccine type and two other vaccines other than inactivated vaccines approved in China on in vitro fertilization (IVF) pregnancy outcomes are rare. To complement and confirm the existing findings, this research aimed to investigate whether there are adverse effects of different vaccine types in females and males on reproductive function and clinical pregnancy.

Methods

This retrospective study enrolled 6,455 fresh embryo transfer cycles at the First Affiliated Hospital of Zhengzhou University between May 1, 2021, and October 31, 2022. The primary outcome is the clinical pregnancy rate (CPR). At the same time, the secondary results are the number of oocytes retrieved, two pronuclei (2PN) rate, blastocyst formation rate, high-quality blastocyst rate, and semen parameters (volume, density, sperm count, forward motility rate, total motility rate, immobility rate, and DNA fragment index (DFI) rate).

Results

In the comparison of ovarian stimulation indicators, no statistically significant differences (P > 0.05) were found in Gn days, endometrial thickness, 2PN rate, metaphase 2 (MII) rate, high-quality embryo rate, and blastocyst formation rate. No significant differences (P>0.05) were found in age, body mass index (BMI), education level, and semen parameters (volume, density, sperm count, forward motility rate, total motility rate, immobility rate, and DFI rate) in these four groups. The multivariate regression model showed that neither the types of vaccines nor the vaccination status of both infertile couples significantly affected clinical pregnancy.

Discussion

The type of vaccine does not appear to have an unfavorable effect on ovarian stimulation, embryo development, semen parameters, and clinical pregnancy.

IgG antibody levels against the SARS-CoV-2 spike protein in mother-child dyads after COVID-19 vaccination

PURPOSE

We aimed to assess IgG antibodies against the SARS-CoV-2 spike protein (anti-SARS-CoV-2 S IgG) in vaccinated mothers and their infants at delivery and 2-3 months of age.

METHODS

We conducted a prospective study on mothers who received at least one dose of the COVID-19 vaccine (Pfizer-BNT162b2, Moderna mRNA-1273, or Oxford-AstraZeneca ChAdOx1-S) during pregnancy and on their infants. The baseline was at the time of delivery (n = 93), and the end of follow-up was 2 to 3 months post-partum (n = 53). Serum anti-SARS-CoV-2 S IgG titers and ACE2 binding inhibition levels were quantified by immunoassays.

RESULTS

Mothers and infants had high anti-SARS-CoV-2 S IgG titers against the B.1 lineage at birth. However, while antibody titers were maintained at 2-3 months post-partum in mothers, they decreased significantly in infants (p < 0.001). Positive and significant correlations were found between anti-SARS-CoV-2 S IgG titers and ACE2-binding inhibition levels in mothers and infants at birth and 2-3 months post-partum (r > 0.8, p < 0.001). Anti-S antibodies were also quantified for the Omicron variant at 2-3 months post-partum. The antibody titers against Omicron were significantly lower in mothers and infants than those against B.1 (p < 0.001). Again, a positive correlation was observed for Omicron between IgG titers and ACE2-binding inhibition both in mothers (r = 0.818, p < 0.001) and infants (r = 0.386, p < 0.005). Previous SARS-CoV-2 infection and COVID-19 vaccination near delivery positively impacted anti-SARS-CoV-2 S IgG levels.

CONCLUSIONS

COVID-19 mRNA vaccines induce high anti-SARS-CoV-2 S titers in pregnant women, which can inhibit the binding of ACE2 to protein S and are efficiently transferred to the fetus. However, there was a rapid decrease in antibody levels at 2 to 3 months post-partum, particularly in infants.

COVID-19 Vaccination and Reproductive Health: a Comprehensive Review for Healthcare Providers

With all the current misinformation on social media platforms about the COVID-19 vaccine and its potential effects on fertility, it is essential for healthcare providers to have evidenced-based research to educate their patients, especially those who are trying to conceive, of the risks to mothers and fetuses of being unvaccinated. It is well known that COVID-19 infection puts pregnant women at higher risk of complications, including ICU admission, placentitis, stillbirth, and death. In February of 2021, the American College of Obstetricians and Gynecologists (ACOG), the American Society for Reproductive Medicine (ASRM), and the Society for Maternal-Fetal Medicine (SMFM) released a statement denying any link between COVID vaccination and infertility. ASRM later confirmed and stated that "everyone, including pregnant women and those seeking to become pregnant, should get a COVID-19 vaccine". In this review, we aim to provide a compilation of data that denies any link between vaccination and infertility for healthcare providers to be able to educate their patients based on evidence-based medicine. We also reviewed the effect of COVID-19 virus and vaccination on various parameters and processes that are essential to obtaining a successful pregnancy.

Comparison of Anti-SARS-CoV-2-Specific Antibody Signatures in Maternal and Infant Blood after COVID-19 Infection versus COVID-19 Vaccination during Pregnancy

OBJECTIVE

 The Advisory Committee on Immunization Practices and The American College of Obstetricians and Gynecologists recommend coronavirus disease 2019 (COVID-19) vaccine for pregnant persons to prevent severe illness and death. The objective was to examine levels of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG, IgM, and IgA against spike protein receptor binding domain (RBD) and nucleocapsid protein (NCP) in maternal and infant/cord blood at delivery after COVID 19 vaccination compared with SARS-CoV-2 infection at in mother-infant dyads at specified time points.

STUDY DESIGN

 Mothers with SARS-CoV-2 infection (n = 31) or COVID-19 vaccination (n = 25) during pregnancy were enrolled between July 2020 and November 2021. Samples were collected at delivery and IgG, IgM, and IgA to RBD of spike and NCPs compared in the infected and vaccinated groups. Timing of infection/vaccination prior to delivery and correlation with antibody levels was performed.

RESULTS

 The majority of participants received vaccination within 90 days of delivery and over half received the Pfizer BioNTech vaccine. There were no significant correlations between antibody levels and timing of infection or vaccination. Infant IgG levels to the RBD domain of spike protein were higher in the vaccinated group (n = 25) as compared with the infants born to mothers with infection (n = 31). Vaccination against COVID-19 during pregnancy was associated with detectable maternal and infant anti-RBD IgG levels at delivery irrespective of the timing of vaccination.

CONCLUSION

 Timing of vaccination had no correlation to the antibody levels suggesting that the timing of maternal vaccination in the cohort did not matter. There was no IgM detected in infants from vaccinated mothers. Infants from vaccinated mothers had robust IgG titers to RBD, which have a lasting protective effect in infants.

KEY POINTS

· COVID-19 vaccination during pregnancy had detectable antibody.. · No correlation between antibody levels and timing of vaccination.. · Infants from vaccinated mothers had robust IgG titers to RBD..

Effectiveness and safety of COVID-19 vaccines on maternal and perinatal outcomes: a systematic review and meta-analysis

OBJECTIVE

To assess the effects of COVID-19 vaccines in women before or during pregnancy on SARS-CoV-2 infection-related, pregnancy, offspring and reactogenicity outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Major databases between December 2019 and January 2023.

STUDY SELECTION

Nine pairs of reviewers contributed to study selection. We included test-negative designs, comparative cohorts and randomised trials on effects of COVID-19 vaccines on infection-related and pregnancy outcomes. Non-comparative cohort studies reporting reactogenicity outcomes were also included.

QUALITY ASSESSMENT, DATA EXTRACTION AND ANALYSIS

Two reviewers independently assessed study quality and extracted data. We undertook random-effects meta-analysis and reported findings as HRs, risk ratios (RRs), ORs or rates with 95% CIs.

RESULTS

Sixty-seven studies (1 813 947 women) were included. Overall, in test-negative design studies, pregnant women fully vaccinated with any COVID-19 vaccine had 61% reduced odds of SARS-CoV-2 infection during pregnancy (OR 0.39, 95% CI 0.21 to 0.75; 4 studies, 23 927 women; I2=87.2%) and 94% reduced odds of hospital admission (OR 0.06, 95% CI 0.01 to 0.71; 2 studies, 868 women; I2=92%). In adjusted cohort studies, the risk of hypertensive disorders in pregnancy was reduced by 12% (RR 0.88, 95% CI 0.82 to 0.92; 2 studies; 115 085 women), while caesarean section was reduced by 9% (OR 0.91, 95% CI 0.85 to 0.98; 6 studies; 30 192 women). We observed an 8% reduction in the risk of neonatal intensive care unit admission (RR 0.92, 95% CI 0.87 to 0.97; 2 studies; 54 569 women) in babies born to vaccinated versus not vaccinated women. In general, vaccination during pregnancy was not associated with increased risk of adverse pregnancy or perinatal outcomes. Pain at the injection site was the most common side effect reported (77%, 95% CI 52% to 94%; 11 studies; 27 195 women).

CONCLUSION

COVID-19 vaccines are effective in preventing SARS-CoV-2 infection and related complications in pregnant women.

PROSPERO REGISTRATION NUMBER

CRD42020178076.

COVID-Vaccines in Pregnancy: Maternal and Neonatal Response over the First 9 Months after Delivery

Vaccination against SARS-CoV-2 has been demonstrated to be safe during gestation. Nevertheless, there are no robust data investigating the entity of maternal antibodies' transmission through the placenta to the newborn and the persistence of the antibodies in babies' serum. The objective of this study is to assess the maternal antibody transmission and kinetics among newborns in the first months of life. Women having received one or two doses of anti-SARS-CoV-2 mRNA-vaccines during pregnancy at any gestational age, and their newborns, were recruited and followed-up over 9 months. Ninety-eight women and 103 babies were included. At birth, we observed a significant positive correlation between maternal and neonatal serum anti-SARS-CoV-2 antibody levels and a significant negative correlation between the time since last dose and antibody levels in mothers with two doses. Over the follow-up, the birth antibody level significantly decreased in time according to the received doses number at 3, 6, and 9 months. During the follow-up, we registered 34 dyad SARS-CoV-2 infection cases. The decreasing trend was slower in the SARS-CoV-2 infection group and among breastfed non-infected babies. Antibodies from maternal anti-SARS-CoV-2 vaccination are efficiently transferred via the placenta and potentially even through breast milk. Among newborns, antibodies show relevant durability in the first months of life.

Maternal and Newborn Outcomes of SARS-CoV-2/COVID-19 and Pregnancy: Parallels and Contrasts with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome

Purpose of Review

Our review aims to compare and contrast Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome and SARS-CoV-2/COVID-19's impact on maternal and neonatal outcomes. We have made significant progress in Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome prevention and treatment over the last few decades. Drawing on empirical evidence with past public health crises can offer valuable insights into dealing with current and future pandemics. Therefore, it is imperative to conduct a comparative analysis of the resemblances and disparities existing between Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome and SARS-CoV-2/COVID-19.This research endeavor represents a pioneering and all-encompassing examination, aiming to discern and comprehend the parallels and contrasts in the respective impacts of SARS-CoV-2 and Human Immunodeficiency Virus on pregnancy.

Recent Findings

Based on the current evidence, there is no indication that pregnancy increases women's susceptibility to acquiring Human Immunodeficiency Virus or SARS-CoV-2. Nevertheless, the state of being pregnant was correlated with the worsening of diseases and their progression. Both Human Immunodeficiency Virus and SARS-CoV-2 pose increased risks of maternal mortality and several obstetric complications, including premature birth and pre-eclampsia. While the vertical transmission of Human Immunodeficiency Virus is well-established, a comprehensive understanding of the vertical transmission of SARS-CoV-2 remains elusive, emphasizing the need for further investigations. Initial data suggest low SARS-CoV-2 vertical transmission rates in the setting of proper preventative interventions and universal screening. A cesarean delivery could reduce the risk of mother-to-child transmission in Human Immunodeficiency Virus-infected women with high viral loads or poor adherence to antiretroviral therapy (ART). However, it did not offer additional protection for Human Immunodeficiency Virus-infected women who adhered to Adherence to Antiretroviral Therapy or those with COVID-19. Human Immunodeficiency Virus and SARS-CoV-2 were linked to neonatal complications such as stillbirth, low birth weight, and neonatal intensive care unit (ICU) admissions. The universal testing of both pregnant patients and neonates is an effective strategy to prevent the spread and complications of both Human Immunodeficiency Virus and SARS-CoV-2. Human Immunodeficiency Virus control largely relies on preventing vertical transmission and medications during pregnancy and postpartum, whereas safety behaviors and vaccines have proven effective in preventing SARS-CoV-2 vertical transmissions.

Summary

This review aims to compare and contrast the impact of Human Immunodeficiency Virus and SARS-CoV-2 on pregnancy outcomes, vertical transmissions, delivery modalities, neonatal outcomes, and clinical management. SARS-CoV-2 and Human Immunodeficiency Virus were associated with significant obstetric-related complications, making close clinical monitoring and preparation essential. Integration of SARS-CoV-2/COVID-19 management with reproductive health services is crucial to ensuring maternal and neonatal outcomes. Our review is not only the first to establish a groundwork for the current state of knowledge and its clinical implications on this topic, but it also sheds new insights for future research directions.Comparing Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome and SARS-CoV-2 in terms of their impact on maternal and neonatal outcomes provides valuable insights despite their differences. Leveraging Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome research can help understand SARS-CoV-2 effects on pregnancy. Both infections pose risks to pregnant individuals and their fetuses, leading to increased maternal mortality and complications. Identifying common patterns and risk factors can improve clinical management for pregnant individuals with SARS-CoV-2. While a direct observational study for this comparison may not be feasible, comparing with Human Immunodeficiency Virus offers an ethical and practical approach. However, specific studies on SARS-CoV-2 are still necessary to gather detailed data on maternal and fetal outcomes.

Reduced control of SARS-CoV-2 infection associates with lower mucosal antibody responses in pregnancy

Pregnant patients are at greater risk of hospitalization with severe COVID-19 than non-pregnant people. This was a retrospective observational cohort study of remnant clinical specimens from patients who visited acute care hospitals within the Johns Hopkins Health System in the Baltimore, MD-Washington DC, area between October 2020 and May 2022. Participants included confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected pregnant people and matched non-pregnant people (the matching criteria included age, race/ethnicity, area deprivation index, insurance status, and vaccination status to ensure matched demographics). The primary dependent measures were clinical COVID-19 outcomes, infectious virus recovery, viral RNA levels, and mucosal anti-spike (S) IgG titers from upper respiratory tract samples. A total of 452 individuals (117 pregnant and 335 non-pregnant) were included in the study, with both vaccinated and unvaccinated individuals represented. Pregnant patients were at increased risk of hospitalization (odds ratio [OR] = 4.2; confidence interval [CI] = 2.0-8.6), intensive care unit admittance (OR = 4.5; CI = 1.2-14.2), and being placed on supplemental oxygen therapy (OR = 3.1; CI = 1.3-6.9). Individuals infected during their third trimester had higher mucosal anti-S IgG titers and lower viral RNA levels (P < 0.05) than those infected during their first or second trimesters. Pregnant individuals experiencing breakthrough infections due to the Omicron variant had reduced anti-S IgG compared to non-pregnant patients (P < 0.05). The observed increased severity of COVID-19 and reduced mucosal antibody responses particularly among pregnant participants infected with the Omicron variant suggest that maintaining high levels of SARS-CoV-2 immunity through booster vaccines may be important for the protection of this at-risk population.IMPORTANCEIn this retrospective observational cohort study, we analyzed remnant clinical samples from non-pregnant and pregnant individuals with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections who visited the Johns Hopkins Hospital System between October 2020 and May 2022. Disease severity, including intensive care unit admission, was greater among pregnant than non-pregnant patients. Vaccination reduced recovery of infectious virus and viral RNA levels in non-pregnant patients, but not in pregnant patients. In pregnant patients, increased nasopharyngeal viral RNA levels and recovery of infectious virus were associated with reduced mucosal IgG antibody responses, especially among women in their first trimester of pregnancy or experiencing breakthrough infections from Omicron variants. Taken together, this study provides insights into how pregnant patients are at greater risk of severe COVID-19. The novelty of this study is that it focuses on the relationship between the mucosal antibody response and its association with virus load and disease outcomes in pregnant people, whereas previous studies have focused on serological immunity. Vaccination status, gestational age, and SARS-CoV-2 omicron variant impact mucosal antibody responses and recovery of infectious virus from pregnant patients.

Pregnancy Outcomes among Pregnant Persons after COVID-19 Vaccination: Assessing Vaccine Safety in Retrospective Cohort Analysis of U.S. National COVID Cohort Collaborative (N3C)

COVID-19 vaccines have been shown to be effective in preventing severe illness, including among pregnant persons. The vaccines appear to be safe in pregnancy, supporting a continuously favorable overall risk/benefit profile, though supportive data for the U.S. over different periods of variant predominance are lacking. We sought to analyze the association of adverse pregnancy outcomes with COVID-19 vaccinations in the pre-Delta, Delta, and Omicron SARS-CoV-2 variants' dominant periods (constituting 50% or more of each pregnancy) for pregnant persons in a large, nationally sampled electronic health record repository in the U.S. Our overall analysis included 311,057 pregnant persons from December 2020 to October 2023 at a time when there were approximately 3.6 million births per year. We compared rates of preterm births and stillbirths among pregnant persons who were vaccinated before or during pregnancy to persons vaccinated after pregnancy or those who were not vaccinated. We performed a multivariable Poisson regression with generalized estimated equations to address data site heterogeneity for preterm births and unadjusted exact models for stillbirths, stratified by the dominant variant period. We found lower rates of preterm birth in the majority of modeled periods (adjusted incidence rate ratio [aIRR] range: 0.42 to 0.85; p-value range: <0.001 to 0.06) and lower rates of stillbirth (IRR range: 0.53 to 1.82; p-value range: <0.001 to 0.976) in most periods among those who were vaccinated before or during pregnancy compared to those who were vaccinated after pregnancy or not vaccinated. We largely found no adverse associations between COVID-19 vaccination and preterm birth or stillbirth; these findings reinforce the safety of COVID-19 vaccination during pregnancy and bolster confidence for pregnant persons, providers, and policymakers in the importance of COVID-19 vaccination for this group despite the end of the public health emergency.

Maternal COVID-19 Vaccination and Prevention of Symptomatic Infection in Infants

BACKGROUND AND OBJECTIVES

Maternal vaccination may prevent infant coronavirus disease 2019 (COVID-19). We aimed to quantify protection against infection from maternally derived vaccine-induced antibodies in the first 6 months of an infant's life.

METHODS

Infants born to mothers vaccinated during pregnancy with 2 or 3 doses of a messenger RNA COVID-19 vaccine (nonboosted or boosted, respectively) had full-length spike (Spike) immunoglobulin G (IgG), pseudovirus 614D, and live virus D614G, and omicron BA.1 and BA.5 neutralizing antibody (nAb) titers measured at delivery. Infant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was determined by verified maternal-report and laboratory confirmation through prospective follow-up to 6 months of age between December 2021 and July 2022. The risk reduction for infection by dose group and antibody titer level was estimated in separate models.

RESULTS

Infants of boosted mothers (n = 204) had significantly higher Spike IgG, pseudovirus, and live nAb titers at delivery than infants of nonboosted mothers (n = 271), and were 56% less likely to acquire infection in the first 6 months (P = .03). Irrespective of boost, for each 10-fold increase in Spike IgG titer at delivery, the infant's risk of acquiring infection was reduced by 47% (95% confidence interval 8%-70%; P = .02). Similarly, a 10-fold increase in pseudovirus titers against Wuhan Spike, and live virus nAb titers against D614G, and omicron BA.1 and BA.5 at delivery were associated with a 30%, 46%, 56%, and 60% risk reduction, respectively.

CONCLUSIONS

Higher transplacental binding and nAb titers substantially reduced the risk of SARS-CoV-2 infection in infants, and a booster dose amplified protection during a period of omicron predominance. Until infants are age-eligible for vaccination, maternal vaccination provides passive protection against symptomatic infection during early infancy.

Impact of coronavirus disease 2019 vaccination on live birth rates after in vitro fertilization

OBJECTIVE

To investigate coronavirus disease 2019 (COVID-19) vaccination on the live birth rates in patients who underwent in vitro fertilization.

DESIGN

Retrospective cohort study.

SETTING

Academic fertility practice.

PATIENT(S)

Patients who underwent fresh or frozen embryo transfer cycles at an academic center between January 1, 2020, and December 31, 2021.

INTERVENTION(S)

Coronavirus disease 2019 vaccination, defined as completing a 2-dose regimen (Pfizer or Moderna) or 1-dose regimen (Johnson & Johnson/Janssen) before cycle initiation.

MAIN OUTCOME MEASURE(S)

The primary outcome was the live birth rate per embryo transfer. The secondary outcomes included positive human chorionic gonadotropin (hCG) and clinical pregnancy rates per embryo transfer. The outcomes from cycles among vaccinated and unvaccinated patients were compared. Descriptive statistics were used to analyze demographic and cycle characteristics using the Student t test and Wilcoxon rank sum, Pearson chi-square, and Fisher exact tests as appropriate for univariate analysis. Generalized estimating equation models were used to examine the strength of the relationship between vaccination status and pregnancy outcomes.

RESULT(S)

Among 709 unvaccinated and 648 vaccinated fresh cycles, no statistically significant differences were observed between the number of oocytes retrieved, oocyte maturity, fertilization, and blastocyst utilization rates. In the adjusted multivariate analysis, no statistically significant differences were noted between fresh cycles among vaccinated patients compared with those among unvaccinated patients with the rates of positive hCG (adjusted odds ratio [aOR], 1.37; 95% confidence interval [CI], 0.84-2.25), clinical pregnancy (aOR, 1.22; 95% CI, 0.73-2.03), or live birth (aOR, 1.37; 95% CI, 0.79-2.25) per embryo transfer. Among 264 unvaccinated and 423 vaccinated frozen embryo transfer (FET) cycles, vaccinated patients had higher odds of positive hCG (aOR, 1.54; 95% CI, 1.08-2.20), clinical pregnancy (aOR, 1.80; 95% CI, 1.27-2.56), and live birth (aOR, 2.31; 95% CI, 1.60-3.32) per embryo transfer than unvaccinated patients.

CONCLUSION(S)

Patients who were COVID-19 vaccinated before FET had higher rates of biochemical pregnancy, clinical pregnancy, and live birth. Vaccination was not associated with the pregnancy or live birth rates after fresh cycles. This study contributes to evidence supporting COVID-19 vaccination for patients attempting pregnancy.

In Utero Exposure to Maternal COVID-19 Vaccination and Offspring Neurodevelopment at 12 and 18 Months

Importance

Uptake of COVID-19 vaccines among pregnant individuals was hampered by safety concerns around potential risks to unborn children. Data clarifying early neurodevelopmental outcomes of offspring exposed to COVID-19 vaccination in utero are lacking.

Objective

To determine whether in utero exposure to maternal COVID-19 vaccination was associated with differences in scores on the Ages and Stages Questionnaire, third edition (ASQ-3), at 12 and 18 months of age.

Design, Setting, and Participants

This prospective cohort study, Assessing the Safety of Pregnancy During the Coronavirus Pandemic (ASPIRE), enrolled pregnant participants from May 2020 to August 2021; follow-up of children from these pregnancies is ongoing. Participants, which included pregnant individuals and their offspring from all 50 states, self-enrolled online. Study activities were performed remotely.

Exposure

In utero exposure of the fetus to maternal COVID-19 vaccination during pregnancy was compared with those unexposed.

Main Outcomes and Measures

Neurodevelopmental scores on validated ASQ-3, completed by birth mothers at 12 and 18 months. A score below the established cutoff in any of 5 subdomains (communication, gross motor, fine motor, problem solving, social skills) constituted an abnormal screen for developmental delay.

Results

A total of 2487 pregnant individuals (mean [SD] age, 33.3 [4.2] years) enrolled at less than 10 weeks' gestation and completed research activities, yielding a total of 2261 and 1940 infants aged 12 and 18 months, respectively, with neurodevelopmental assessments. In crude analyses, 471 of 1541 exposed infants (30.6%) screened abnormally for developmental delay at 12 months vs 203 of 720 unexposed infants (28.2%; χ2 = 1.32; P = .25); the corresponding prevalences at 18 months were 262 of 1301 (20.1%) vs 148 of 639 (23.2%), respectively (χ2 = 2.35; P = .13). In multivariable mixed-effects logistic regression models adjusting for maternal age, race, ethnicity, education, income, maternal depression, and anxiety, no difference in risk for abnormal ASQ-3 screens was observed at either time point (12 months: adjusted risk ratio [aRR], 1.14; 95% CI, 0.97-1.33; 18 months: aRR, 0.88; 95% CI, 0.72-1.07). Further adjustment for preterm birth and infant sex did not affect results (12 months: aRR, 1.16; 95% CI, 0.98-1.36; 18 months: aRR, 0.87; 95% CI, 0.71-1.07).

Conclusions and Relevance

Results of this cohort study suggest that COVID-19 vaccination was safe during pregnancy from the perspective of infant neurodevelopment to 18 months of age. Additional longer-term research should be conducted to corroborate these findings and buttress clinical guidance with a strong evidence base.

Protective efficacy of a Zika purified inactivated virus vaccine candidate during pregnancy in marmosets

Zika virus (ZIKV) infection during pregnancy poses significant threats to maternal and fetal health, leading to intrauterine fetal demise and severe developmental malformations that constitute congenital Zika syndrome (CZS). As such, the development of a safe and effective ZIKV vaccine is a critical public health priority. However, the safety and efficacy of such a vaccine during pregnancy remain uncertain. Historically, the conduct of clinical trials in pregnant women has been challenging. Therefore, clinically relevant animal pregnancy models are in high demand for testing vaccine efficacy. We previously reported that a marmoset pregnancy model of ZIKV infection consistently demonstrated vertical transmission from mother to fetus during pregnancy. Using this marmoset model, we also showed that vertical transmission could be prevented by pre-pregnancy vaccination with Zika purified inactivated virus (ZPIV) vaccine. Here, we further examined the efficacy of ZPIV vaccination during pregnancy. Vaccination during pregnancy elicited virus neutralizing antibody responses that were comparable to those elicited by pre-pregnancy vaccination. Vaccination also reduced placental pathology, viral burden and vertical transmission of ZIKV during pregnancy, without causing adverse effects. These results provide key insights into the safety and efficacy of ZPIV vaccination during pregnancy and demonstrate positive effects of vaccination on the reduction of ZIKV infection, an important advance in preparedness for future ZIKV outbreaks.

Determinants of SARS-CoV-2 IgG response and decay in Canadian healthcare workers: A prospective cohort study

INTRODUCTION

Healthcare workers (HCWs) from an interprovincial Canadian cohort gave serial blood samples to identify factors associated with anti-receptor binding domain (anti-RBD) IgG response to the SARS-CoV-2 virus.

METHODS

Members of the HCW cohort donated blood samples four months after their first SARS-CoV-2 immunization and again at 7, 10 and 13 months. Date and type of immunizations and dates of SARS-CoV-2 infection were collected at each of four contacts, together with information on immunologically-compromising conditions and current therapies. Blood samples were analyzed centrally for anti-RBD IgG and anti-nucleocapsid IgG (Abbott Architect, Abbott Diagnostics). Records of immunization and SARS-CoV-2 testing from public health agencies were used to assess the impact of reporting errors on estimates from the random-effects multivariable model fitted to the data.

RESULTS

2752 of 4567 vaccinated cohort participants agreed to donate at least one blood sample. Modelling of anti-RBD IgG titer from 8903 samples showed an increase in IgG with each vaccine dose and with first infection. A decrease in IgG titer was found with the number of months since vaccination or infection, with the sharpest decline after the third dose. An immunization regime that included mRNA1273 (Moderna) resulted in higher anti-RBD IgG. Participants reporting multiple sclerosis, rheumatoid arthritis or taking selective immunosuppressants, tumor necrosis factor inhibitors, calcineurin inhibitors and antineoplastic agents had lower anti-RBD IgG. Supplementary analyses showed higher anti-RBD IgG in those reporting side-effects of vaccination, no relation of anti-RBD IgG to obesity and lower titers in women immunized in early or mid-pregnancy. Sensitivity analysis results suggested no important bias in the self-report data.

CONCLUSION

Creation of a prospective cohort was central to the credibility of results presented here. Serial serology assessments, with longitudinal analysis, provided effect estimates with enhanced accuracy and a clearer understanding of medical and other factors affecting response to vaccination.

Messenger RNA Therapy for Female Reproductive Health

Female reproductive health has traditionally been an underrepresented area of research in the drug delivery sciences. This disparity is also seen in the emerging field of mRNA therapeutics, a class of medicines that promises to treat and prevent disease by upregulating protein expression in the body. Here, we review advances in mRNA therapies through the lens of improving female reproductive health. Specifically, we begin our review by discussing the fundamental structure and biochemical modifications associated with mRNA-based drugs. Then, we discuss various packaging technologies, including lipid nanoparticles, that can be utilized to protect and transport mRNA drugs to target cells in the body. Last, we conclude our review by discussing the usage of mRNA therapy for addressing pregnancy-related health and vaccination against sexually transmitted diseases in women. Of note, we also highlight relevant clinical trials using mRNA for female reproductive health while also providing their corresponding National Clinical Trial identifiers. In undertaking this review, our aim is to provide a fundamental background understanding of mRNA therapy and its usage to specifically address female health issues with an overarching goal of providing information toward addressing gender disparity in certain aspects of health research.

Assessing the Knowledge and Attitudes of Breastfeeding During the COVID-19 Pandemic

Background It is generally accepted that breastfeeding is a practice that provides valuable health benefits to both mother and baby. However, the COVID-19 pandemic unveiled questions regarding the safety of breastfeeding, leading to potential hesitation among the public. Our study seeks to appreciate the public's understanding and attitudes toward breastfeeding during the COVID-19 pandemic. Methods An anonymous survey was distributed online through social media platforms. Demographic information was collected with questions specifically analyzing the knowledge and attitude of each participant. Calculations were performed using Spearman's rho correlations to determine significant differences. Results Thirty-nine women were recruited. The average overall knowledge score was 93% correct. 87% of participants believe breastfeeding is better than formula feeding, and 92% stated they would breastfeed their infant if they knew it could protect their child from COVID-19. Discussion The results of our study indicated that although overall knowledge of breastfeeding during the COVID-19 pandemic was well understood, higher levels of education may play a role in the depth of one's knowledge. In addition, while participants were reporting high levels of education about breastfeeding from their healthcare providers, few were receiving data specific to the pandemic. The data gathered from this study may help to target future educational initiatives.

Assessment of Female Hormonal Influence on COVID-19 Vaccine Response: A Prospective Cohort Study

INTRODUCTION

The diversity of oral epithelial cells offers potential viral infection sites. The lower level of ACE2 inhibitors in women's blood renders them more resistant to coronavirus disease 2019 (COVID-19). In order to determine the effect of COVID-19 vaccination on female hormones, salivary levels of total antibody, immunoglobulin G (IgG), and cortisol were measured in young and elderly women.

METHODS

Saliva samples from 88 participants were collected and subjected to ELISA for detecting total antibody, IgG, and cortisol.

RESULTS

Women who were infected with COVID-19 and who completed two doses of vaccination had more IgG antibodies when compared to the uninfected individuals/single-dose/non-vaccinated individuals. The cortisol levels in post-menopausal women were higher than those in women with normal menstrual cycles, and the difference was statistically significant (P-value 0.00). The increased cortisol levels were well correlated with increased levels of IgG antibodies which was statistically significant (Spearman rho P value 0.00) Conclusions: COVID variants will continue to mutate and evolve as long as the epidemic persists. The higher cortisol and IgG antibodies produced by female hormones protect them from COVID-19 infection.

A Population-Based Test-Negative Matched Case-Control Analysis of SARS-CoV-2 Vaccine Effectiveness Among Pregnant People in Ontario, Canada

OBJECTIVE

Pregnancy is a risk factor for severe SARS-CoV-2 infection, which can result in adverse pregnancy outcomes, thus making understanding vaccine effectiveness (VE) in this population important. This study aimed to assess the VE of mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infection and COVID-19-related hospitalization in pregnant people.

METHODS

Population-based matched test-negative case-control study of pregnant people aged 18-49 years, of 12 or more weeks gestation in Ontario, Canada, symptomatic with possible SARS-CoV-2 infection, and having at least 1 positive (n = 1842) or negative (n = 8524) real-time polymerase chain reaction (RT-PCR) SARS-CoV-2 test between December 14, 2020, and December 31, 2021. The exposure was receipt of ≥1 dose of mRNA COVID-19 vaccine versus no vaccination. Exposure was further stratified by number and recency of doses. The primary outcome was a positive SARS-CoV-2 RT-PCR test. As a secondary outcome, VE for COVID-19-related hospitalization was assessed.

RESULTS

In the primary outcome analysis, there were 1821 positive cases, matched to 1821 negative controls. The mean (SD) maternal age was 31 (5) years. When compared to those unvaccinated, receipt of ≥1 dose was associated with an estimated VE of 39% (95% CI 29%-48%) for symptomatic infection, and 85% (95% CI 72%-92%) for COVID-19 hospitalization. VE estimates demonstrated waning with increased time since last vaccination.

CONCLUSIONS

mRNA COVID-19 vaccines provide protection against symptomatic COVID-19 illness and are highly effective at preventing severe illness in pregnant people. The observed effect of vaccine waning highlights the importance of booster doses to provide optimal protection for pregnant people.

SARS-CoV-2 antibodies and their neutralizing capacity against live virus in human milk after COVID-19 infection and vaccination: prospective cohort studies

BACKGROUND

There is limited understanding of the impact of coronavirus disease 2019 (COVID-19) infection and vaccination type and interval on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) human milk antibodies and their neutralizing capacity.

OBJECTIVES

These cohort studies aimed to determine the presence of antibodies and live virus neutralizing capacity in milk from females infected with COVID-19, unexposed milk bank donors, and vaccinated females and examine impacts of vaccine interval and type.

METHODS

Milk was collected from participants infected with COVID-19 during pregnancy or lactation (Cohort-1) and milk bank donors (Cohort-2) from March 2020-July 2021 at 3 sequential 4-wk intervals and COVID-19 vaccinated participants with varying dose intervals (Cohort-3) (January-October 2021). Cohort-1 and Cohort-3 were recruited from Sinai Health (patients) and through social media. Cohort-2 included Ontario Milk Bank donors. Milk was examined for SARS-CoV-2 antibodies and live virus neutralization.

RESULTS

Of females with COVID-19, 53% (Cohort-1, n = 55) had anti-SARS-CoV-2 IgA antibodies in ≥1 milk sample. IgA+ samples (40%) were more likely neutralizing than IgA- samples (odds ratio [OR]: 2.18; 95% confidence interval [CI]: 1.03, 4.60; P = 0.04); however, 25% of IgA- samples were neutralizing. Both IgA positivity and neutralization decreased ∼6 mo after symptom onset (0-100 compared with 201+ d: IgA OR: 14.30; 95% CI: 1.08, 189.89; P = 0.04; neutralizing OR: 4.30; 95% CI: 1.55, 11.89; P = 0.005). Among milk bank donors (Cohort-2, n = 373), 4.3% had IgA antibodies; 23% of IgA+ samples were neutralizing. Vaccination (Cohort-3, n = 60) with mRNA-1273 and shorter vaccine intervals (3 to <6 wk) resulted in higher IgA and IgG than BNT162b2 (P < 0.04) and longer intervals (6 to <16 wk) (P≤0.02), respectively. Neutralizing capacity increased postvaccination (P = 0.04) but was not associated with antibody positivity.

CONCLUSIONS

SARS-CoV-2 infection and vaccination (type and interval) impacted milk antibodies; however, antibody presence did not consistently predict live virus neutralization. Although human milk is unequivocally the best way to nourish infants, guidance on protection to infants following maternal infection/vaccination may require more nuanced messaging. This study was registered at clinicaltrials.gov as NCT04453969 and NCT04453982.

Description of maternal and neonatal adverse events in pregnant people immunised with COVID-19 vaccines during pregnancy in the CLAP NETWORK of sentinel sites. Nested case-control analysis of the immunization-associated risk: A study protocol

INTRODUCTION

COVID-19 is associated with higher morbimortality in pregnant people compared with non-pregnant people. At present, the benefits of maternal immunisation are considered to outweigh the risks, and therefore, vaccination is recommended during pregnancy. However, additional information is needed on the safety of the vaccines in this population.

METHODS AND ANALYSIS

This a retrospective cohort nested case-control study in pregnant people who attended maternity hospitals from eight Latin American and Caribbean countries. A perinatal electronic clinical history database with neonatal and obstetric information will be used. The proportion of pregnant people immunised with COVID-19 vaccines of the following maternal and neonatal events will be described: preterm infant, small for gestational age, low birth weight, stillbirth, neonatal death, congenital malformations, maternal near miss and maternal death. Moreover, the risk of prematurity, small for gestational age and low birth weight associated with exposure to COVID-19 vaccines will be estimated. Each case will be matched with two groups of three randomly selected controls. Controls will be matched by hospital and mother's age (±3 years) with an additional matching by delivery date and conception time in the first and second control groups, respectively. The estimated required sample size for the main analysis (exposure to any vaccine) concerning 'non-use' is at least 1009 cases (3027 controls) to detect an increased probability of vaccine-associated event risk of 30% and at least 650 cases (1950 controls) to detect 30% protection. Sensitivity and secondary analyses considering country, type of vaccine, exposure windows and completeness of immunisation will be reported.

ETHICS

The study protocol was reviewed by the Ethical Review Committee on Research of the Pan American Health Organization. Patient informed consent was waived due to the retrospective design and the utilisation of anonymised data (Ref. No: PAHOERC.0546.01). Results will be disseminated in open access journals.

Neoantigen vaccine nanoformulations based on Chemically synthesized minimal mRNA (CmRNA): small molecules, big impact

Recently, chemically synthesized minimal mRNA (CmRNA) has emerged as a promising alternative to in vitro transcribed mRNA (IVT-mRNA) for cancer therapy and immunotherapy. CmRNA lacking the untranslated regions and polyadenylation exhibits enhanced stability and efficiency. Encapsulation of CmRNA within lipid-polymer hybrid nanoparticles (LPPs) offers an effective approach for personalized neoantigen mRNA vaccines with improved control over tumor growth. LPP-based delivery systems provide superior pharmacokinetics, stability, and lower toxicity compared to viral vectors, naked mRNA, or lipid nanoparticles that are commonly used for mRNA delivery. Precise customization of LPPs in terms of size, surface charge, and composition allows for optimized cellular uptake, target specificity, and immune stimulation. CmRNA-encoded neo-antigens demonstrate high translational efficiency, enabling immune recognition by CD8+ T cells upon processing and presentation. This perspective highlights the potential benefits, challenges, and future directions of CmRNA neoantigen vaccines in cancer therapy compared to Circular RNAs and IVT-mRNA. Further research is needed to optimize vaccine design, delivery, and safety assessment in clinical trials. Nevertheless, personalized LPP-CmRNA vaccines hold great potential for advancing cancer immunotherapy, paving the way for personalized medicine.

A case series exploring the human milk polyclonal IgA1 response to repeated SARS-CoV-2 vaccinations by LC-MS based fab profiling

Introduction

Upon vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) humans will start to produce antibodies targeting virus specific antigens that will end up in circulation. In lactating women such antibodies will also end up in breastmilk, primarily in the form of secretory immunoglobulin A1 (SIgA1), the most abundant immunoglobulin (Ig) in human milk. Here we set out to investigate the SIgA1 clonal repertoire response to repeated SARS-CoV-2 vaccination, using a LC-MS fragment antigen-binding (Fab) clonal profiling approach.

Methods

We analyzed the breastmilk of six donors from a larger cohort of 109 lactating mothers who received one of three commonly used SARS-CoV-2 vaccines. We quantitatively monitored the SIgA1 Fab clonal profile over 16 timepoints, from just prior to the first vaccination until 15  days after the second vaccination.

Results

In all donors, we detected a population of 89-191 vaccine induced clones. These populations were unique to each donor and heterogeneous with respect to individual clonal concentrations, total clonal titer, and population size. The vaccine induced clones were dominated by persistent clones (68%) which came up after the first vaccination and were retained or reoccurred after the second vaccination. However, we also observe transient SIgA1 clones (16%) which dissipated before the second vaccination, and vaccine induced clones which uniquely emerged only after the second vaccination (16%). These distinct populations were observed in all analyzed donors, regardless of the administered vaccine.

Discussion

Our findings suggest that while individual donors have highly unique human milk SIgA1 clonal profiles and a highly personalized SIgA1 response to SARS-CoV-2 vaccination, there are also commonalities in vaccine induced responses.

Safety of COVID-19 Vaccination During Pregnancy and Lactation: A VigiBase Analysis

BACKGROUND

There is limited evidence on the safety of coronavirus disease 2019 (COVID-19) vaccination during pregnancy and lactation. Thus, we aimed to evaluate the association between COVID-19 vaccination during pregnancy and lactation and reporting risk of adverse pregnancy or lactation outcomes.

METHODS

Using VigiBase, we performed a disproportionality analysis with case/non case design. Cases were defined based on the Standardized MedDRA Queries (SMQs) of "pregnancy and neonatal topics" and non-cases were defined as all other adverse events. We included all reports with COVID-19 vaccines as the suspected cause. Using the full database as the comparators, reporting odds ratios (RORs) with 95% confidence intervals (CIs) were estimated by logistic regression while adjusting for maternal age. Infants' age and sex were additionally adjusted in analyzing the risk of COVID-19 vaccination during lactation.

RESULTS

We identified 10,266 and 6,474 reports with the SMQ of "pregnancy and neonatal topics" associated with COVID-19 vaccines during pregnancy and lactation, respectively. No significant RORs of adverse pregnancy outcomes associated with COVID-19 vaccines during pregnancy were observed; however, "functional lactation disorders" showed significant disproportionality during lactation with adjusted ROR of 1.48 (95% CI, 1.21-1.79). Further analysis that analyzed "functional lactation disorders" at a preferred term level, showed higher ROR in mastitis (2.76 [95% CI, 1.45-5.27]).

CONCLUSION

Overall, we did not observe a positive association between COVID-19 vaccination during pregnancy and risk of reporting adverse pregnancy outcomes. However, we found a significant disproportionate reporting association between COVID-19 vaccination during lactation and "functional lactation disorders", specifically mastitis. Continuous surveillance is warranted to confirm the safety of COVID-19 vaccine during pregnancy and lactation.

Responses to Common Misconceptions Relating to COVID-19 Variant-Adapted mRNA Vaccines

The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the waning of immunity over time has necessitated the use of booster doses of original coronavirus disease 2019 (COVID-19) vaccines. This has also led to the development and implementation of variant-adapted messenger RNA (mRNA) vaccines that include an Omicron sub-lineage component in addition to the antigen based on the wild-type virus spike protein. Subsequent emergence of the recombinant XBB sub-lineages triggered the development of monovalent XBB-based variant-adapted mRNA vaccines, which are available for vaccination campaigns in late 2023. Misconceptions about new variant-adapted vaccines may exacerbate vaccine fatigue and drive the lack of vaccine acceptance. This article aims to address common concerns about the development and use of COVID-19 variant-adapted mRNA vaccines that have emerged as SARS-CoV-2 has continued to evolve.

SARS-CoV-2 neutralizing antibody titers in maternal blood, umbilical cord blood, and breast milk

OBJECTIVE

We quantified neutralizing SARS-CoV-2 antibody against spike protein (nAb) levels after vaccination and SARS-CoV-2 infection in maternal serum, cord blood, and breast milk and determined whether they correlate with levels of spike protein binding antibody.

STUDY DESIGN

Women (n = 100) were enrolled on admission for delivery. Previous SARS-CoV-2 infection was defined by anti-nucleocapsid antibodies. Levels of nAb and binding antibodies against spike receptor binding domain were measured in maternal blood, cord blood, and milk.

RESULTS

Maternal nAb levels were higher after vaccine and infection than vaccine alone but waned rapidly. Levels of nAb in cord blood and milk correlated with maternal levels and were higher in cord blood than maternal. Spike protein binding antibody levels correlated with nAb.

CONCLUSION

SARS-CoV-2 vaccination near delivery may boost antibody-mediated immunity in the peripartum period. Neutralizing antibodies are passed transplacentally and into milk. Spike protein binding antibody may be a feasible proxy for nAb.

A narrative review of COVID-19 vaccination in pregnancy and breastfeeding

The Coronavirus pandemic has affected millions of people due to the spread of the Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) virus. Pregnant individuals and infants are most vulnerable given the increased risk of developing severe complications from SARS-CoV-2 infection. Recently, COVID-19 vaccination is recommended for pregnant women and infants starting at 6 months of age to prevent disease contraction and minimize disease severity. We conducted a review of the literature on COVID-19 vaccination to discuss vaccine safety and efficacy, immunity after maternal vaccination, transplacental transfer and persistence of antibodies, and public health implications. Current evidence supports the safety and efficacy of vaccination during pregnancy. Maternal vaccination provides greater antibody persistence in infants compared to immunity from natural infection. Furthermore, vaccination has demonstrated an increased rate of passive antibody transfer through the placenta and breast milk. Public health interventions are important in achieving herd immunity and ultimately ending the pandemic. IMPACT: This article highlights the benefits of COVID-19 vaccination during pregnancy with a review of the data describing safety and efficacy, passive and active immunity after maternal immunization, trans-placental transfer and persistence of protective antibodies, and public health implications. With this information, healthcare providers can provide up-to-date knowledge to their pregnant patients to help them form an informed decision on vaccination and combat vaccine hesitancy.

Applications of SARS-CoV-2 serological testing: impact of test performance, sample matrices, and patient characteristics

Laboratory testing has been a key tool in managing the SARS-CoV-2 global pandemic. While rapid antigen and PCR testing has proven useful for diagnosing acute SARS-CoV-2 infections, additional testing methods are required to understand the long-term impact of SARS-CoV-2 infections on immune response. Serological testing, a well-documented laboratory practice, measures the presence of antibodies in a sample to uncover information about host immunity. Although proposed applications of serological testing for clinical use have previously been limited, current research into SARS-CoV-2 has shown growing utility for serological methods in these settings. To name a few, serological testing has been used to identify patients with past infections and long-term active disease and to monitor vaccine efficacy. Test utility and result interpretation, however, are often complicated by factors that include poor test sensitivity early in infection, lack of immune response in some individuals, overlying infection and vaccination responses, lack of standardization of antibody titers/levels between instruments, unknown titers that confer immune protection, and large between-individual biological variation following infection or vaccination. Thus, the three major components of this review will examine (1) factors that affect serological test utility: test performance, testing matrices, seroprevalence concerns and viral variants, (2) patient factors that affect serological response: timing of sampling, age, sex, body mass index, immunosuppression and vaccination, and (3) informative applications of serological testing: identifying past infection, immune surveillance to guide health practices, and examination of protective immunity. SARS-CoV-2 serological testing should be beneficial for clinical care if it is implemented appropriately. However, as with other laboratory developed tests, use of SARS-CoV-2 serology as a testing modality warrants careful consideration of testing limitations and evaluation of its clinical utility.

Management of neonates with maternal prenatal coronavirus infection and influencing factors

The coronavirus disease 2019 (COVID-19) in pregnancy causes adverse outcomes for both the mother and the fetus. Neonates are at risk of vertical transmission and in-utero infection. Additionally, intensive care unit (ICU) admission and impairment in the organ systems of the mother are associated with neonatal outcomes, including impaired intrauterine growth, prematurity, and neonatal ICU admission. The management of neonates born from infected mothers has changed over the progress of the pandemic. At the beginning of the pandemic, cesarean section, immediate separation of mother-infant dyads, isolation of neonates, and avoiding of skin-to-skin contact, breast milk, and breastfeeding were the main practices to reduce vertical and horizontal transmission risk in the era of insufficient knowledge. The effects of antenatal steroids and delayed cord clamping on COVID-19 were also not known. As the pandemic progressed, data showed that prenatal, delivery room, and postnatal care of neonates can be performed as pre-pandemic practices. Variants and vaccines that affect clinical course and outcomes have emerged during the pandemic. The severity of the disease and the timing of infection in pregnancy also influence maternal and neonatal outcomes. The knowledge and lessons from COVID-19 will be helpful for the next pandemic if it happens. IMPACT: Prenatal infection with COVID-19 is associated with adverse maternal and neonatal outcomes. Our review includes the management of neonates with prenatal COVID-19 infection exposure, maternal-fetal, delivery room, and postnatal care of neonates, clinical features, treatment of neonates, and influencing factors such as variants, vaccination, severity of maternal disease, and timing of infection during pregnancy. There is a growing body of data and evidence about the COVID-19 pandemic. The knowledge and lessons from the pandemic will be helpful for the next pandemic if it happens.

Non-Viral RNA Delivery During Pregnancy: Opportunities and Challenges

During pregnancy, the risk of maternal and fetal adversities increases due to physiological changes, genetic predispositions, environmental factors, and infections. Unfortunately, treatment options are severely limited because many essential interventions are unsafe, inaccessible, or lacking in sufficient scientific data to support their use. One potential solution to this challenge may lie in emerging RNA therapeutics for gene therapy, protein replacement, maternal vaccination, fetal gene editing, and other prenatal treatment applications. In this review, the current landscape of RNA platforms and non-viral RNA delivery technologies that are under active development for administration during pregnancy is explored. Advancements of pregnancy-specific RNA drugs against SARS-CoV-2, Zika, influenza, preeclampsia, and for in-utero gene editing are discussed. Finally, this study highlights bottlenecks that are impeding translation efforts of RNA therapies, including the lack of accurate cell-based and animal models of human pregnancy and concerns related to toxicity and immunogenicity during pregnancy. Overcoming these challenges will facilitate the rapid development of this new class of pregnancy-safe drugs.

Pregnancy and SARS-CoV-2 infection with a focus on its vertical transmission, breastfeeding, cord blood banking, and vaccination during COVID-19 infection

The SARS-CoV-2 outbreak led to a health crisis worldwide. This infection can infect individuals, particularly pregnant women. In this review, we tried to find the possibility of vertical transmission of COVID-19 and investigate the effects of COVID-19 on pregnancy, breastfeeding, cord blood banking, and the effects of recommended vaccines on pregnant and lactating women. Keywords include COVID-19, congenital infection, SARS-CoV-2, pregnancy, and COVID-19 vaccines. Vertical transmission of SARS-CoV-2 was searched in scientific databases, such as PubMed, Google Scholar, and Scopus. The criteria for including studies in this article are the study of SARS-CoV-2 infection in pregnant women, fetuses, and neonates during pregnancy and while breastfeeding, and also the effect of COVID-19 vaccines on them. There are several conflicting results in the transmission of SARS-CoV-2 from the maternal-fetal interface. Since many neonates born from COVID-19-infected mothers had no signs of this infection, the possibility of SARS-CoV-2 congenital transmission cannot be confirmed. Also, SARS-CoV-2-infected women can breastfeed their babies if they have mild symptoms. Up till now, no adverse effect of COVID-19 vaccines has been identified on mothers, infants, and the fertility of men or women. Even so, more investigations are needed on the long-term effects of COVID-19 vaccines.

Investigating the impact of Sinopharm COVID-19 vaccination on antibody response in pregnant women and their newborns

This study aims to investigate the levels of receptor-binding domain (RBD), spike, and neutralizing antibodies in pregnant women who received the Sinopharm vaccine and their newborns. A cross-sectional study was conducted at a tertiary center, Mashhad, Iran. We included 88 pregnant women who had received at least two doses of the Sinopharm vaccine. Maternal and umbilical cord blood samples taken at delivery were analyzed for antibodies using ELISA tests. Antibody levels did not vary significantly between women with two or three vaccine doses. Only 1.1% of mothers had undetectable levels of RBD antibodies, but detectable antibodies were observed in all newborns. A significant linear correlation was found between the levels of neutralizing antibodies (r = 0.7, p < 0.001) and RBD antibodies (r = 0.833, p < 0.001) in mothers and their newborns, but not for Spike antibodies (r = 0.214, p = 0.045). In mothers, high titers of antispike and RBD antibodies were observed at the time of delivery. The high titers of RBD and antispike antibodies were found in cord blood, suggesting potential neonatal immunity. Detectable levels of antibodies were found in both groups, regardless of the timing of vaccination. The Sinopharm vaccine generates detectable levels of antibodies in pregnant women, which are efficiently transferred to their newborns. The number of vaccine doses (two or three) did not significantly impact the levels of detectable antibodies. This underscores Sinopharm's potential efficacy in protecting pregnant women and their infants from COVID-19.

Viruses and Human Milk: Transmission or Protection?

Human milk (HM) is considered the best source of nutrition for infant growth and health. This nourishment is unique and changes constantly during lactation to adapt to the physiological needs of the developing infant. It is also recognized as a potential route of transmission of some viral pathogens although the presence of a virus in HM rarely leads to a disease in an infant. This intriguing paradox can be explained by considering the intrinsic antiviral properties of HM. In this comprehensive and schematically presented review, we have described what viruses have been detected in HM so far and what their potential transmission risk through breastfeeding is. We have provided a description of all the antiviral compounds of HM, along with an analysis of their demonstrated and hypothesized mechanisms of action. Finally, we have also analyzed the impact of HM pasteurization and storage methods on the detection and transmission of viruses, and on the antiviral compounds of HM. We have highlighted that there is currently a deep knowledge on the potential transmission of viral pathogens through breastfeeding and on the antiviral properties of HM. The current evidence suggests that, in most cases, it is unnecessarily to deprive an infant of this high-quality nourishment and that the continuation of breastfeeding is in the best interest of the infant and the mother.

SARS-CoV-2 Antibody Profiles in Maternal Serum and Breast Milk Following mRNA COVID-19 Vaccination: A Longitudinal Prospective Observational Cohort Study

COVID-19 vaccination during pregnancy protects infants against symptomatic COVID-19. Vaccination of lactating mothers may offer additional protection, but our understanding of immune responses in breast milk is limited. We, therefore, performed a single-center prospective cohort study of lactating mothers who received a COVID-19 mRNA primary vaccine series to evaluate the durability, breadth, and neutralizing capacity of the antibody responses in breast milk. Spike IgG- and IgA-binding antibodies of ancestral SARS-CoV-2 in serum and breast milk were quantified over 9 months using Meso Scale Discovery (MSD) V-PLEX assays, and ancestral titers were compared to four variants of concern (Alpha, Beta, Delta, Gamma) at a single time point. Neutralizing antibodies against ancestral SARS-CoV-2 and Omicron BA.4/5 were compared before and after vaccination using a pseudovirus-neutralization assay. Eleven lactating mothers received either Pfizer BNT162b2 (7/11) or Moderna mRNA-1273 (4/11) vaccine primary series. IgG and IgA titers increased in serum and breast milk following each dose, peaking 1-4 weeks after series completion. Titers remained significantly elevated for 7-9 months, except for in breast milk IgA which returned to baseline within 1 month. Furthermore, binding antibodies against all included variants were detected in breast milk collected 1-3 weeks after series completion. However, while vaccination induced a strong neutralizing response against ancestral SARS-CoV-2 in serum and more modest response in breast milk, it did not induce neutralizing antibodies against Omicron BA.4/5 in either specimen type. This study demonstrates that maternal COVID-19 mRNA vaccination may enhance immune protection for infants through breast milk via increased IgG- and IgA-binding-and-neutralizing antibodies; although, variant-specific boosters may be required to optimize immune protection.

Pregnancy outcomes following natural conception and assisted reproduction treatment in women who received COVID-19 vaccination prior to conception: a population-based cohort study in China

Introduction

The coronavirus disease-2019 (COVID-19) pandemic has swept across the world and continues to exert serious adverse effects on vulnerable populations, including pregnant women and neonates. The vaccines available at present were designed to prevent infection from COVID-19 strains and control viral spread. Although the incidence of pregnancy cycle outcomes are not likely to increase patients vaccinated prior to pregnancy compared with unvaccinated patients based on our knowledge of vaccination safety, there is no specific evidence to support this hypothesis. Therefore, the current study aimed to investigate the association between maternal vaccination prior to conception and pregnancy outcomes.

Methods

We retrospectively analyzed 2,614 women who received prenatal care and delivered in the Obstetrical Department of The First Affiliated Hospital of Anhui Medical University between February 2022 and November 2022. Of the 1,380 eligible pregnant women, 899 women who had received preconception vaccination were assigned to a vaccine group and 481 women who were not vaccinated were control group. Of the enrolled patients, 291 women received fertility treatment (141 vaccinated women, 150 unvaccinated women). The primary outcomes were pregnancy complications (hypothyroidism, gestational diabetes mellitus, pregnancy-induced hypertension, polyhydramnios, oligohydramnios, premature rupture of membranes and postpartum hemorrhage), obstetric outcomes (preterm birth rate, cesarean section rate) and neonatal outcomes (birth-weight, body length, low-birth-weight rate, rate of congenital defects, neonatal mortality and admission to the neonatal intensive care unit).

Results

There was no significant difference in the incidence of complications during pregnancy and delivery when compared between the vaccine group and control group in either univariate- or multivariate-models. The type of vaccine was not associated with the odds of adverse pregnancy outcome. Among the women with infertility treatment, the vaccinated group and the unvaccinated group had similar pregnancy outcomes.

Conclusion

Women who received COVID-19 vaccination prior to conception had similar maternal and neonatal outcomes as women who were unvaccinated. Our findings indicate that COVID-19 vaccinations can be safely administered prior to pregnancy in women who are planning pregnancy or assisted reproductive treatment. During new waves of COVID-19 infection, women who are planning pregnancy should be vaccinated as soon as possible to avoid subsequent infections.

mRNA vaccines against respiratory viruses

PURPOSE OF REVIEW

The successes of the coronavirus disease 2019 (COVID-19) mRNA vaccines have accelerated the development of mRNA vaccines against other respiratory pathogens. The aim of this review is to highlight COVID-19 mRNA vaccine advances and provide an update on the progress of mRNA vaccine development against other respiratory pathogens.

RECENT FINDINGS

The COVID-19 mRNA vaccines demonstrated effectiveness in preventing severe COVID-19 and death. H7N9 and H10N8 avian influenza mRNA vaccines have demonstrated safety and immunogenicity in phase 1 clinical trials. Numerous seasonal influenza mRNA vaccines are in phase 1-3 clinical trials. Respiratory syncytial virus (RSV) mRNA vaccines have progressed to phase 2-3 clinical trials in adults and a phase 1 clinical trial in children. A combined human metapneumovirus and parainfluenza-3 mRNA vaccines was found to be well tolerated and immunogenic in a phase 1 trial among adults and trials are being conducted among children. Clinical trials of mRNA vaccines combining antigens from multiple respiratory viruses are underway.

SUMMARY

The development of mRNA vaccines against respiratory viruses has progressed rapidly in recent years. Promising vaccine candidates are moving through the clinical development pathway to test their efficacy in preventing disease against respiratory viral pathogens.

Covid-19 vaccination and pregnancy: a systematic review of maternal and neonatal outcomes

OBJECTIVES

Although the vaccination against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS Cov-2) is considered safe during pregnancy, vaccine hesitancy among pregnant women is high. The results of published observational studies addressing the issue of Covid-19 vaccination's efficacy and safety during pregnancy need to be summarized.

CONTENT

This systematic review compares the incidence of major maternal and neonatal outcomes between SARS Cov-2 vaccinated and unvaccinated pregnant women. The included studies enrolled pregnant women of any age and any trimester. Medline-Pubmed, Scopus, Cochrane Library, and grey literature were searched until the 28th of May 2022, and 2,947 studies were found.

SUMMARY

Seven observational cohort studies, enrolling 67,274 pregnant women, were selected. When comparing vaccinated and unvaccinated pregnant women, SARS Cov-2 vaccines were not associated with major maternal and neonatal adverse events. The rate of SARS Cov-2 infections among vaccinated pregnant women compared to unvaccinated is significantly reduced by 43%.

OUTLOOK

SARS Cov-2 vaccination in pregnant women is effective and safe. The results are promising, but caution is advised due to some limitations: only observational studies addressing this issue were found. Parallelly, the enrolled populations and the intervention (vaccination type and the number of doses) were not homogeneous.

Breastmilk from COVID-19 negative lactating mothers shows neutralizing activity against SARS-COV-2

Breastmilk protects newborns from infections through specific and nonspecific compounds. This study investigated the neutralizing activity against SARS-CoV-2 of breastmilk from SARS-CoV-2 negative, unvaccinated mothers, and compared it to that from infected nursing mothers. We enrolled women after COVID-19 swab testing results upon maternity admission, and divided them into two groups: group A, COVID-19-positive mothers, and group B, negative mothers. Breastmilk was randomly sampled at 2, 7, and 20 days postpartum. We collected 19 samples for Group A and 41 for Group B. A microneutralization assay was used to determine the 50% neutralization (NT50) titre. The presence of neutralizing antibodies was also determined. Group A had 100% neutralizing samples at 2 days postpartum (T0), declining 7 days postpartum (T1) and 20 days postpartum (T2). Group B samples exhibited neutralizing activity mostly at 7 days postpartum (T1) (90%). Negative mothers' samples showed no correlation between NT50 titres and antibodies' presence, suggesting that non-specific breastmilk components may exert antiviral action against SARS-CoV-2.

Serum concentration of antigen-specific IgG can substantially bias interpretation of antibody-dependent phagocytosis assay readout

Because virus neutralization cannot solely explain vaccine-induced, antibody-mediated protection, antibody effector functions are being considered as a potential correlate of protection (CoP). However, measuring effector functions at a fixed serum dilution for high throughput purposes makes it difficult to distinguish between the effect of serum antibody concentration and antibody properties such as epitopes, subclass, and glycosylation. To address this issue, we evaluated antibody-dependent cellular phagocytosis (ADCP) assay against SARS-CoV-2 spike. Adjustment of serum samples to the same concentration of antigen-specific IgG prior to the ADCP assay revealed concentration-independent differences in ADCP after mRNA vaccination in subjects with and without prior SARS-CoV-2 infection not detectable in assay performed with fixed serum dilution. Phagocytosis measured at different concentrations of spike-specific IgG strongly correlated with the area under the curve (AUC) indicating that ADCP assay can be performed at a standardized antibody concentration for the high throughput necessary for vaccine trial analyses.

Reduced maternal immunity and vertical transfer of immunity against SARS-CoV-2 variants of concern with COVID-19 exposure or initial vaccination in pregnancy

Introduction

As the SARS-CoV-2 pandemic continues to evolve, we face new variants of concern with a concurrent decline in vaccine booster uptake. We aimed to evaluate the difference in immunity gained from the original SARS-CoV-2 mRNA vaccine series in pregnancy versus SARS-CoV-2 exposure during pregnancy against recent variants of concern.

Study Design

This is a retrospective analysis of previously collected samples from 192 patients who delivered between February 2021 and August 2021. Participants were categorized as 1) COVID vaccine: mRNA vaccine in pregnancy, 2) COVID-exposed, and 3) controls. The primary outcome was neutralizing capacity against wild-type, Delta, and Omicron-B1 between cohorts. Secondary outcomes include a comparison of cord-blood ID50 as well as the efficiency of vertical transfer, measured by cord-blood:maternal blood ID50 for each variant.

Results

Pregnant women with COVID-19 vaccination had a greater spike in IgG titers compared to both those with COVID-19 disease exposure and controls. Both COVID exposure and vaccination resulted in immunity against Delta, but only COVID vaccination resulted in significantly greater Omicron ID-50 versus controls. The neutralizing capacity of serum from newborns was lower than that of their mothers, with COVID-vaccination demonstrating higher cord-blood ID50 vs wildtype and Delta variants compared to control or COVID-exposed, but neither COVID-exposure nor vaccination demonstrated significantly higher Omicron ID50 in cord-blood compared to controls. There was a 0.20 (0.07-0.33, p=0.004) and 0.12 (0.0-0.24, p=0.05) increase in cord-blood:maternal blood ID50 with COVID vaccination compared to COVID-19 exposure for wild-type and Delta respectively. In pair-wise comparison, vertical transfer of neutralization capacity (cord-blood:maternal blood ID50) was greatest for wild-type and progressively reduced for Delta and Omicron ID50.

Conclusion

Pregnant patients with either an initial mRNA vaccination series or COVID-exposure demonstrated reduced immunity against newer variants compared to wild-type as has been reported for non-pregnant individuals; however, the COVID-vaccination series afforded greater cross-variant immunity to pregnant women, specifically against Omicron, than COVID-disease. Vertical transfer of immunity is greater in those with COVID vaccination vs COVID disease exposure but is reduced with progressive variants. Our results reinforce the importance of bivalent booster vaccination in pregnancy for both maternal and infant protection and also provide a rationale for receiving updated vaccines as they become available.

Balance between maternal antiviral response and placental transfer of protection in gestational SARS-CoV-2 infection

The intricate interplay between maternal immune response to SARS-CoV-2 and the transfer of protective factors to the fetus remains unclear. By analyzing mother-neonate dyads from second and third trimester SARS-CoV-2 infections, our study shows that neutralizing antibodies (NAbs) are infrequently detected in cord blood. We uncovered that this is due to impaired IgG-NAb placental transfer in symptomatic infection and to the predominance of maternal SARS-CoV-2 NAbs of the IgA and IgM isotypes, which are prevented from crossing the placenta. Crucially, the balance between maternal antiviral response and transplacental transfer of IgG-NAbs appears to hinge on IL-6 and IL-10 produced in response to SARS-CoV-2 infection. In addition, asymptomatic maternal infection was associated with expansion of anti-SARS-CoV-2 IgM and NK cell frequency. Our findings identify a protective role for IgA/IgM-NAbs in gestational SARS-CoV-2 infection and open the possibility that the maternal immune response to SARS-CoV-2 infection might benefit the neonate in 2 ways, first by skewing maternal immune response toward immediate viral clearance, and second by endowing the neonate with protective mechanisms to curtail horizontal viral transmission in the critical postnatal period, via the priming of IgA/IgM-NAbs to be transferred by the breast milk and via NK cell expansion in the neonate.

Maternal Immunization During the Second Trimester with BNT162b2 mRNA Vaccine Induces a Robust IgA Response in Human Milk: A Prospective Cohort Study

BACKGROUND

The human milk antibody response following maternal immunization with the BNT162b2 mRNA vaccine is important for the protection of the infant during infancy. The vaccine-specific antibody response is still unclear at different stages of human milk production, as are the effects of maternal immunization timing on the robustness of the antibody response.

OBJECTIVES

The study aimed to assess the antibody response (IgG/IgA/IgM) during various lactation stages and identify the best vaccination timing during pregnancy.

METHODS

A prospective cohort study of 73 postpartum women who were administered the BNT162b2 COVID-19 mRNA vaccine during the second or third trimester of pregnancy were recruited. Statistical comparison was conducted using 16 human milk samples from a prepandemic control group.

RESULTS

Excluding 11 women, the study included 62 lactating women who were administered the mRNA vaccine during the second or third trimester of pregnancy. A total of 149 samples of human milk were collected at different lactation stages. Our findings reveal that colostrum exhibits significantly higher levels of IgG (95% confidence interval [CI]: 1.3, 9.0; P = 0.023), IgA (95% CI: 55.98, 100.2; P = 0.0034), and IgM (95% CI: 0.03, 0.62; P < 0.0001) compared with mature milk IgG (95% CI: 0.25, 0.43), IgA (95% CI: 9.65, 13.74), IgM (95% CI: 0.03, 0.04). The timing of maternal immunization affected the antibody response. The level of IgA in mature milk was higher when immunization occurred in the second trimester (95% CI: 11.14, 19.66; P = 0.006) than in the third trimester (95% CI: 7.16, 11.49). Conversely, IgG levels in mature milk were higher when immunization occurred during the third trimester (95% CI: 0.36, 0.65; P < 0.0001) than in the second trimester (95% CI: 0.09, 0.38).

CONCLUSIONS

Our study provides evidence that administering the mRNA vaccine to pregnant women during the second trimester increases vaccine-specific IgA levels during lactation. Considering the significance of human milk IgA in mucosal tissues and its prevalence throughout lactation, it is reasonable to recommend maternal immunization with the BNT162b2 mRNA vaccine during the second trimester. This trial was registered at the Helsinki Committee of the Tel Aviv Medical Center as clinical trial number 0172-TLV.

How safe is COVID-19 vaccination among pregnant women and its outcome - A hospital-based retrospective study in Indian population

Background

Although getting the Covid infection is equal for every person, during pregnancy, the women's immunity is a little lower than usual, so they are more prone to infection. That is why they should be taken care of with more precautions. A vaccine is the best weapon to fight such infection. Covishield and Covaxin are the two vaccines first introduce in country India including for pregnant women. The safety of the vaccine was a big concern as one of them is a newer type of vaccine. The current study was planned with objectives to understand the safety aspect of Covid19 vaccine on pregnancy outcome and Adverse events following immunization (AEFI) following vaccination.

Materials and Methods

This was a hospital-based retrospective cohort study. The sample size was all the pregnant women who delivered a baby from July 2021 to April 2022 at the tertiary care hospital in Vadodara. These women were retrospectively assessed for the status of vaccination based on the record and other information related to ANC from the record. Total of 1974 women were eligible for study after inclusion-exclusion criteria. The collected data was analysed.

Result

Of the 1974 pregnant women, 531 (27%) took any of one covid19 vaccine and 1443 (73%) did not take vaccine. There were 511 (96%) women opted for Covishield vaccine and 20 (4%) women who opted for Covaxin. Of 531 women who took vaccination, 46% women had AEFI. The risk of low birth weight (LBW) baby was 40% among vaccinated v/s 39% among non-vaccinated and congenital malformation was 0.6% among vaccinated v/s 1% among non-vaccinated women. On the contrary, the risk of premature birth was 8% among the vaccinated group v/s 13% among the non-vaccinated group and NICU admission following delivery was 8% among the vaccinated group v/s 12% among the non-vaccinated group.

Conclusion

AEFI among pregnant women were found less compared to the general population. The study also revealed that both Covishield and Covaxin are found safe for pregnancy outcomes and can be given to pregnant women during any trimester of pregnancy message for a family physician.

SARS-CoV-2 vaccination, booster, and infection in pregnant population enhances passive immunity in neonates

The effects of heterogeneous infection, vaccination and boosting histories prior to and during pregnancy have not been extensively studied and are likely important for protection of neonates. We measure levels of spike binding antibodies in 4600 patients and their neonates with different vaccination statuses, with and without history of SARS-CoV-2 infection. We investigate neutralizing antibody activity against different SARS-CoV-2 variant pseudotypes in a subset of 259 patients and determined correlation between IgG levels and variant neutralizing activity. We further study the ability of maternal antibody and neutralizing measurements to predict neutralizing antibody activity in the umbilical cord blood of neonates. In this work, we show SARS-CoV-2 vaccination and boosting, especially in the setting of previous infection, leads to significant increases in antibody levels and neutralizing activity even against the recent omicron BA.1 and BA.5 variants in both pregnant patients and their neonates.

Fetal Cardiac Hemodynamic and Sonographic Anomalies in Maternal COVID-19 Infection Depending on Vaccination Status-Polish Multicenter Cohort Study

Most obstetrical studies have focused on maternal response to the SARS-CoV-2 virus but much less is known about the effect of COVID-19 on fetal physiology. We aimed to evaluate the effect of the maternal SARS-CoV-2 infection on the fetal homeostasis with the use of detailed ultrasonography and echocardiography and consideration of the effect of vaccination. This was a multi-center study of fetuses who had prenatal detailed ultrasound and echocardiographic examinations performed by fetal cardiology specialists. The subjects were divided based on the COVID vaccination status (vaccinated women who did not have COVID-group V, unvaccinated women who had COVID-group UV, and unvaccinated women who did not have COVID-control group). We evaluated the ultrasound and echocardiography results obtained. The study group included 237 gravidas from four prenatal cardiology centers. In the group of fetuses with normal heart anatomy, normal cardiovascular function had 147 (81%) fetuses and functional cardiovascular anomalies were present in 35 (19%) cases. Functional cardiovascular anomalies were present in 11 (16%) fetuses in the V group, 19 (47%) fetuses in the UV group and 5 (8%) fetuses in the control group (p < 0.01). There were 56 (24%) fetuses with extracardiac anomalies. Extracardiac anomalies were present in 20 (22%) fetuses in the V group, 22 (45%) fetuses of the UV group and in 14 (14%) fetuses in the control group (p < 0.01). Our study has proved that maternal COVID-19 infection can affect the fetal physiology and mild cardiac and extracardiac markers detected by fetal ultrasonography and echocardiography. Moreover, maternal vaccination results in lower occurrence of these findings in fetuses.

Vertical transmission and maternal passive immunity post-SARS-CoV-2

Since 2020, the highly contagious nature and various transmission routes of SARS-CoV-2 have rendered the pandemic interminable. Vertical transmission (VT) through the placenta and breast milk, which is frequent for certain virus types, is thought to exist for SARS-CoV-2 and is hypothesized by many researchers. Conversely, antibodies are produced to counteract the effect of viruses. Since newborns' immunologic system cannot produce proper antibodies, maternal antibodies are usually transferred from mother to infant/fetus to meet the need. This theory leads to the hypothesis of transmission of antibodies through the placenta and breast milk following SARS-CoV-2 infection or vaccination. This paper further discusses these hypotheses, considering consequences of fetus/infant harm versus benefit.