SARS-CoV-2 and the Immune Response in Pregnancy with Delta Variant Considerations

Association Between SARS-CoV-2 Infection During Pregnancy and Gestational Diabetes: A Claims-based Cohort Study

INTRODUCTION

Coronavirus disease 2019 (COVID-19) may be associated with gestational diabetes mellitus (GDM); however, evidence is limited by sample sizes and lack of control groups.

METHODS

To assess the GDM risk after COVID-19 in pregnancy, we constructed a retrospective cohort of pregnancies ending March 2020-October 2022 using medical claims. People with COVID-19 diagnosis claims from conception to 21 gestational weeks (n = 57 675) were matched 1:2 to those without COVID-19 during pregnancy (n = 115 350) by age range, pregnancy start month, and encounter year-month. GDM (claim ≥23 gestational weeks) relative risk and risk difference overall, by race and ethnicity, and variant period were estimated using log-binomial models.

RESULTS

GDM risk was higher among those with COVID-19 during pregnancy compared to those without (adjusted risk ratio [aRR] = 1.12; 95% confidence interval [CI], 1.08-1.15). GDM risk was significantly associated with COVID-19 in non-Hispanic White (aRR = 1.08; 95% CI, 1.04-1.14), non-Hispanic Black (aRR = 1.15; 95% CI, 1.07-1.24), and Hispanic (aRR = 1.17; 95% CI, 1.10-1.24) groups. GDM risk was significantly higher during pre-Delta (aRR = 1.17; 95% CI, 1.11-1.24) compared to Omicron (aRR = 1.07; 95% CI, 1.02-1.13) periods, but neither differed from the Delta period (aRR = 1.10; 95% CI, 1.04-1.17). The adjusted risk difference was 0%-2% for all models.

CONCLUSIONS

COVID-19 during pregnancy was modestly associated with GDM in claims-based data, especially during earlier SARS-CoV-2 variant periods. Because these associations are based on COVID-19 in claims data, studies employing systematic testing are warranted.

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.

Retrospective Cohort Study Comparing the Clinical Profile and Outcomes of Critically Ill Pregnant Patients in Kuwait during the COVID-19 Pandemic Waves

OBJECTIVES

COVID-19 is an infectious disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2 virus). This virus evolved into several variants, each with different severity. There are surges in the number of infected patients, commonly described as "waves." In Kuwait, three waves occurred. Our study describes and compares the clinical presentation and outcomes of critically ill pregnant patients infected with different variants.

METHODS

This was a retrospective cohort study in two intensive care units (ICU) dedicated to patients with COVID-19. The wave periods were retrieved from the Kuwait Ministry of Health.

RESULTS

The total number of ICU admissions during the study period was 74 patients. Most cases occurred during the third wave (n = 47/74, 63.5%). Most patients did not have comorbidities. The most common presenting symptoms were fever 62.2%, dyspnea 71.6%, and dry cough 74.3%. Low oxygen saturation 35.1% and maternal tachycardia 75.7% were observed in most patients. Cesarean section was the most common route of delivery, with maternal indication accounting for most cases 78.84%. Eight patients (13.69%) underwent dialysis, and thirty-one (41.9%) needed extracorporeal membrane oxygenation. Most patients required ventilatory support 66.21%. Almost all patients were unvaccinated 97.01%. Maternal mortality was mainly noted in the third wave (13.23%).

CONCLUSIONS

In Kuwait, the number of admissions and the rate of maternal complications, morbidity, and mortality increased with successive waves.

Case report: Complex evaluation of coagulation, fibrinolysis and inflammatory cytokines in a SARS-CoV-2 infected pregnant woman with fetal loss

Background

SARS-CoV-2 infection during pregnancy increases the risk of severe obstetrical complications. Detailed evaluation of COVID-19-associated coagulopathy in a pregnancy with stillbirth hasn't been described so far. Besides knowledge gaps in the pathomechanism leading to stillbirth in COVID-19 pregnancies, currently, no prognostic biomarker is available to identify pregnant patients who are at imminent risk of COVID-19-associated maternal and fetal complications, requiring immediate medical attention.

Case

Here we report the case of a 28-year-old SARS-CoV-2 infected pregnant patient, admitted to our hospital at 28 weeks of gestation with intrauterine fetal loss. The presence of SARS-CoV-2 placentitis was confirmed by immunohistological evaluation of the placenta. She had only mild upper respiratory symptoms and her vital signs were within reference throughout labor and postpartum. The stillborn infant was delivered per vias naturales. Fibrinogen concentrate was administered before and after labor due to markedly decreased fibrinogen levels (1.49 g/l) at admission and excessive bleeding during and after delivery. Although coagulation screening tests were not alarming at admission, the balance of hemostasis was strikingly distorted in the patient. As compared to healthy age- and gestational age-matched pregnant controls, increased D-dimer, low FVIII activity, low FXIII level, marked hypocoagulability as demonstrated by the thrombin generation assay, together with shortened clot lysis and decreased levels of fibrinolytic proteins were observed. These alterations most likely have contributed to the increased bleeding observed during labor and in the early postpartum period. Interestingly, at the same time, only moderately altered inflammatory cytokine levels were found at admission. Serum ACE2 activity did not differ in the patient from that of age- and gestational age-matched healthy controls, suggesting that despite previous speculations in the literature, ACE2 may not be used as a potential biomarker for the prediction of COVID-19 placentitis and threatening fetal loss in SARS-CoV-2-infected pregnancies.

Conclusions

Although based on this case report no prognostic biomarker could be identified for use in pregnant patients with imminent risk of fetal loss associated with COVID-19 placentitis, the above-described hemostasis alterations warrant awareness of postpartum hemorrhagic complications and could be helpful to identify patients requiring intensified medical attention.

Analysis of the transplacental transmission of SARS CoV-2 virus and antibody transfer according to the gestational age at maternal infection

To quantify transplacental transmission of SARS-CoV-2 virus and antibody transfer in pregnant women and their newborns according to the gestational age at maternal infection. A prospective observational multicenter study including pregnant women with a positive RT-PCR or a positive serology for SARS-CoV-2 and compatible symptoms, from April to December 2020, in 11 French maternities. The study was designed to obtain a systematic collection of mother-infant dyad's samples at birth. SARS-CoV-2 viral load was measured by RT-PCR. IgG and IgM antibodies against the SARS-CoV-2 spike protein were measured by enzyme-linked immunosorbent assay. Antibody concentrations and transplacental transfer ratios were analyzed according to the gestational age at maternal infection. The primary outcome was the rate of SARS CoV-2 materno-fetal transmission at birth. The secondary outcome was the quantification of materno-fetal antibody transfer. Maternal and neonatal outcomes at birth were additionally assessed. Among 165 dyads enrolled, one congenital infection was confirmed {n = 1 (0.63%) IC95% [0.02%; 3.48%]}. The average placental IgG antibody transfer ratio was 1.27 (IC 95% [0.69-2.89]). The transfer ratio increased with increasing time between the onset of maternal infection and delivery (P Value = 0.0001). Maternal and neonatal outcomes were reassuring. We confirmed the very low rate of SARS-CoV-2 transplacental transmission (< 1%). Maternal antibody transfer to the fetus was more efficient when the infection occurred during the first and second trimester of pregnancy.

Efficacy and safety of therapies for COVID-19 in pregnancy: a systematic review and meta-analysis

BACKGROUND

Clinical evidence suggests that pregnant women are more vulnerable to COVID-19, since they are at increased risk for disease progression and for obstetric complications, such as premature labor, miscarriage, preeclampsia, cesarean delivery, fetal growth restriction and perinatal death. Despite this evidence, pregnant women are often excluded from clinical trials, resulting in limited knowledge on COVID-19 management. The aim of this systematic review and meta-analysis is to provide better evidence on the efficacy and safety of available COVID-19 treatment in pregnant women.

METHODS

Four authors searched major electronic databases from inception until 1 st November-2022 for controlled trials/observational studies, investigating outcomes after the administration of anti-SARS-CoV-2 treatments in pregnant women affected by COVID-19. The analyses investigated the cumulative incidence of delivery and maternal outcomes in pregnant women, comparing those taking active medication vs standard care. Risk ratios (RRs) with 95% confidence intervals were calculated. Statistical significance was assessed using the random effects model and inverse-variance method. This systematic review and meta-analysis was conducted in accordance with the updated 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The protocol has been registered in Prospero (number registration: CRD42023397445).

RESULTS

From initially 937 non duplicate records, we assessed the full texts of 40 articles, finally including ten studies. In six studies, including 1627 patients, the use of casirivimab/imdevimab (CAS/IMD), remdesivir, and IFN-alpha 2b significantly decreased the need of cesarean section ((RR = 0.665; 95%CI: 0.491-0.899; p = 0.008; I 2 = 19.5%;) (Table 1, (Fig. 1). Treatments did not decrease the risk of preterm delivery, admission to neonatal ICU, or stillbirth/perinatal loss (p-values > 0.50 for all these outcomes) and did not prevent the progression of disease towards severe degrees (k = 8; 2,374 pregnant women; RR = 0.778; 95%CI: 0.550-1.099; p = 0.15; I 2 = 0%). Moreover, the use of medications during pregnancy did not modify the incidence of maternal death in two studies (Table 2).

CONCLUSIONS

To our analysis, CAS/IMD, remdesivir, and IFN alpha 2b reduced the number of cesarean sections but demonstrated no effect on disease progression and other obstetric and COVID-19 related outcomes. The inability to evaluate the influence of viral load on illness development in pregnant women was attributed to lack of data. In our systematic review, no major side effects were reported. Though, it is essential for the medical community to focus more on clinical trials and less on episodic case reports and case series, with standardization of fetal and maternal outcomes.

The course of infection with the Delta variant of COVID-19 in pregnancy: analysis of clinical, laboratory, and neonatal outcomes

Objective

This study aimed to examine the effects of infection with the Delta variant of coronavirus disease-2019 (COVID-19) on the clinical course, laboratory parameters, and neonatal outcome in pregnant women.

Material and Methods

A total of 96 pregnant women who tested positive for the Delta variant of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) causing COVID-19 were retrospectively examined. The pregnant women were divided into three groups: Asymptomatic; non-severe; and severe. Age, obstetric history, symptoms and findings, blood tests, medication and vaccination history, clinical course, and perinatal outcome of pregnant women were analyzed.

Results

Pregnant women who tested positive for the Delta variant of SARS-CoV-2 had an intensive care unit (ICU) admission rate of 9.4% and a mortality rate of 5.2%. Pregnant women in the severe disease group had significantly higher rates of preterm birth and cesarean section compared with the non-severe and asymptomatic group. Pregnant women in the severe group had high C-reactive protein (CRP) levels at the time of admission. White blood cell count (WBC) and procalcitonin levels were increased in clinical follow-up in women in the severe group.

Conclusion

The Delta variant of SARS-CoV-2 was found to increase mortality rates in pregnant women compared to pre-Delta variants of COVID-19. In pregnant women infected with the Delta variant, advanced gestational age at diagnosis, high CRP, WBC, and procalcitonin levels were significantly correlated with poor prognosis. Pregnant women infected with the Delta variant and with severe COVID-19 had an increased risk for preterm delivery and cesarean section. Although newborns of women with severe disease were found to have significantly higher rates of ICU admission, there was no significant difference in neonatal mortality rates. We recommend close monitoring of CRP, WBC, and procalcitonin levels, in addition to symptoms, in pregnant women infected with the Delta variant of SARS-CoV-2 and diagnosed in the third trimester.

Association of food habit with the COVID-19 severity and hospitalization: A cross-sectional study among the recovered individuals in Bangladesh

Background: It was assumed that dietary habits might influence the status of COVID-19 patients. Aim: We aimed at the identification of association of dietary habits with the COVID-19 severity and hospitalization. Methods: It was a retrospective cross-sectional study (n = 1025). We used bivariate and multivariate analyses to correlate the association between self-reported dietary patterns and COVID-19 severity and hospitalization. Results: Dietary habits (black tea, milked tea, pickles, black caraway seeds, honey, fish, fruits, vegetables, garlic, onion and turmeric) were identified with lower risk of COVID-19 severity and hospitalization. Interestingly, the consumption frequency (one-, two- or three-times/day) of rice - the staple food in Bangladesh - was not associated with COVID-19 severity and hospitalization for comorbid patients. In contrast, a moderate rice-eating habit (two times/day) was strongly associated with the lower risk of severity and hospitalization for non-comorbid patients. However, for both comorbid and non-comorbid patients, consumption of black tea, milked tea, pickles and honey were associated with a lower likelihood of severity and hospitalization. Overall, a high consumption (three-times/day) of fish, fruits and vegetables, a moderate consumption of garlic, onion and turmeric spices and a daily intake of black/milked tea, and honey were associated with reduced risk of COVID-19 severity and hospitalization. Conclusions: To reduce the severity of COVID-19, a habitual practice of intaking black tea, milked tea, black caraway seeds and honey along with dietary habit (rice, fish and vegetables) and with a moderate consumption of ginger, garlic, onion, mixed aromatic spices (cinnamon + cardamom + cloves) and turmeric might be suggested.

Association of Infection with Different SARS-CoV-2 Variants during Pregnancy with Maternal and Perinatal Outcomes: A Systematic Review and Meta-Analysis

The aim of this study is to review the currently available data, and to explore the association of infection with different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants during pregnancy with maternal and perinatal outcomes in the real world. Observational cohort studies were analyzed that described the maternal and perinatal outcomes of infection with different SARS-CoV-2 variants during pregnancy. Random-effects inverse-variance models were used to evaluate the pooled prevalence (PP) and its 95% confidence interval (CI) for maternal and perinatal outcomes. Random effects were used to estimate the pooled odds ratios (OR) and their 95% CI for different outcomes between Delta and pre-Delta periods, and between Omicron and Delta periods. Eighteen studies, involving a total of 133,058 cases of SARS-CoV-2 infection during pregnancy (99,567 cases of SARS-CoV-2 wild type or pre-variant infection and 33,494 cases of SARS-CoV-2 variant infections), were included in this meta-analysis. Among pregnant women with SARS-CoV-2 infections, the PPs for required respiratory support, severe or critical illness, intensive care unit (ICU) admission, maternal death, and preterm birth <37 weeks were, respectively, 27.24% (95%CI, 20.51−33.97%), 24.96% (95%CI, 15.96−33.96%), 11.31% (95%CI, 4.00−18.61%), 4.20% (95%CI, 1.43−6.97%), and 33.85% (95%CI, 21.54−46.17%) in the Delta period, which were higher than those in the pre-Delta period, while the corresponding PPs were, respectively, 10.74% (95%CI, 6.05−15.46%), 11.99% (95%CI, 6.23−17.74%), 4.17% (95%CI, 1.53−6.80%), 0.63% (95%CI, 0.05−1.20%), and 18.58% (95%CI, 9.52−27.65%). The PPs for required respiratory support, severe or critical illness, and ICU admission were, respectively, 2.63% (95%CI, 0.98−4.28%), 1.11% (95%CI, 0.29−1.94%), and 1.83% (95%CI, 0.85−2.81%) in the Omicron period, which were lower than those in the pre-Delta and Delta periods. These results suggest that Omicron infections are associated with less severe maternal and neonatal adverse outcomes, though maternal ICU admission, the need for respiratory support, and preterm birth did also occur with Omicron infections. Since Omicron is currently the predominant strain globally, and has the highest rates of transmission, it is still important to remain vigilant in protecting the vulnerable populations of mothers and infants. In particular, obstetricians and gynecologists should not ignore the adverse risks of maternal ICU admission, respiratory support, and preterm births in pregnant patients with SARS-CoV-2 infections, in order to protect the health of mothers and infants.

SARS-CoV-2 Variants, Current Vaccines and Therapeutic Implications for COVID-19

Over the past two years, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused hundreds of millions of infections, resulting in an unprecedented pandemic of coronavirus disease 2019 (COVID-19). As the virus spreads through the population, ongoing mutations and adaptations are being discovered. There is now substantial clinical evidence that demonstrates the SARS-CoV-2 variants have stronger transmissibility and higher virulence compared to the wild-type strain of SARS-CoV-2. Hence, development of vaccines against SARS-CoV-2 variants to boost individual immunity has become essential. However, current treatment options are limited for COVID-19 caused by the SARS-CoV-2 variants. In this review, we describe current distribution, variation, biology, and clinical features of COVID-19 caused by SARS-CoV-2 variants (including Alpha (B.1.1.7 Lineage) variant, Beta (B.1.351 Lineage) variant, Gamma (P.1 Lineage) variant, Delta (B.1.617.2 Lineage) variant, and Omicron (B.1.1.529 Lineage) variant and others. In addition, we review currently employed vaccines in clinical or preclinical phases as well as potential targeted therapies in an attempt to provide better preventive and treatment strategies for COVID-19 caused by different SARS-CoV-2 variants.

Effect of SARS-CoV-2 infection in neonates or in pregnancy on developmental outcomes at 21-24 months (SINEPOST): study protocol for a prospective cohort study

INTRODUCTION

Exposure to SARS-CoV-2 during pregnancy or in the neonatal period may impact fetal or neonatal brain development either through direct central nervous system infection or indirectly through the adverse effects of viral infection-related inflammation in the mother or newborn infant. This study aims to determine whether there are early neurodevelopmental effects of SARS-CoV-2 infection.

METHODS AND ANALYSIS

We will conduct a prospective national population-based cohort study of children aged 21-24 months who were born at term (≥37 weeks' gestation) between 1 March 2020 and 28 February 2021 and were either antenatally exposed, neonatally exposed or unexposed (comparison cohort) to SARS-CoV-2. Nationally, hospitals will identify and approach parents of children eligible for inclusion in the antenatally and neonatally exposed cohorts using information from the UK Obstetric Surveillance System (UKOSS) and British Paediatric Surveillance Unit (BPSU) national surveillance studies and will identify and approach eligible children for the comparison cohort through routine birth records. Parents will be asked to complete questionnaires to assess their child's development at 21-24 months of age. Outcome measures comprise the Ages and Stages Questionnaire, Third Edition (ASQ-3), Ages and Stages Questionnaire Social-Emotional, Second Edition (ASQ-SE-2), Liverpool respiratory symptoms questionnaire and questionnaire items to elicit information about healthcare usage. With parental consent, study data will be linked to routine health and education records for future follow-up. Regression models will compare ASQ-3 and ASQ-SE-2 scores and proportions, frequency of respiratory symptoms and healthcare usage between the exposed and comparison cohorts, adjusting for potential confounders.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the London-Westminster Research Ethics Committee. Findings will be disseminated in scientific conference presentations and peer-reviewed publications.

ISRCTN REGISTRATION NUMBER

ISRCTN99910769.

Impact of COVID-19 pandemic on the pregnancy outcomes of women undergoing assisted reproductive techniques (ARTs): a systematic review and meta-analysis

The global outbreak of the coronavirus disease 2019 (COVID-19) led to the suspension of most treatments with assisted reproductive technique (ART). However, with the recent successful control of the pandemic in China, there is an urgent public need to resume full reproductive care. To determine whether the COVID-19 pandemic had any adverse effects on female fertility and the pregnancy outcomes of women undergoing ART, a systematic review and meta-analysis was conducted using the electronic Chinese and English databases. Dichotomous outcomes were summarized as prevalence, and odds ratios (ORs) and continuous outcomes as standardized mean difference (SMD) with 95% confidence interval (CI). The risk of bias and subgroup analyses were assessed using Stata/SE 15.1 and R 4.1.2. The results showed that compared with women treated by ART in the pre-COVID-19 time frame, women undergoing ART after the COVID-19 pandemic exhibited no significant difference in the clinical pregnancy rate (OR 1.07, 95% CI 0.97 to 1.19; I²=0.0%), miscarriage rate (OR 0.95, 95% CI 0.79 to 1.14; I²=38.4%), embryo cryopreservation rate (OR 2.90, 95% CI 0.17 to 48.13; I²=85.4%), and oocyte cryopreservation rate (OR 0.30, 95% CI 0.03 to 3.65; I²=81.6%). This review provided additional evidence for gynecologists to guide the management of women undergoing ART treatment during the COVID-19 pandemic timeframe.

COVID-19 and the Immune Response: A Multi-Phasic Approach to the Treatment of COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a viral agent that causes Coronavirus disease 2019 (COVID-19), a disease that causes flu-like symptoms that, when exacerbated, can have life-threatening consequences. COVID-19 has been linked to persistent symptoms, sequelae, and medical complications that can last months after the initial infection. This systematic review aims to elucidate the innate and adaptive immune mechanisms involved and identify potential characteristics of COVID-19 pathology that may increase symptom duration. We also describe he three different stages of COVID-19—viral replication, immune hyperactivation, and post-acute sequelae—as well as each phase’s corresponding immune response. Finally, we use this multiphasic approach to describe different treatment approaches for each of the three stages—antivirals, immunosuppressants and monoclonal antibodies, and continued immunosuppressants—to fully curate the treatment to the stage of disease.

Brixia and qSOFA Scores, Coagulation Factors and Blood Values in Spring versus Autumn 2021 Infection in Pregnant Critical COVID-19 Patients: A Preliminary Study

(1) Background: From the recent variants of concern of the SARS-CoV-2 virus, in which the delta variant generated more negative outcomes than the alpha, we hypothesized that lung involvement, clinical condition deterioration and blood alterations were also more severe in autumn infection, when the delta variant dominated (compared with spring infections, when the alpha variant dominated), in severely infected pregnant patients. (2) Methods: In a prospective study, all pregnant patients admitted to the ICU of the Elena Doamna Obstetrics and Gynecology Hospital with a critical form of COVID-19 infection-spring group (n = 11) and autumn group (n = 7)-between 1 January 2021 and 1 December 2021 were included. Brixia scores were calculated for every patient: A score, upon admittance; H score, the highest score throughout hospitalization; and E score, at the end of hospitalization. For each day of Brixia A, H or E score, the qSOFA (quick sepsis-related organ failure assessment) score was calculated, and the blood values were also considered. (3) Results: Brixia E score, C-reactive protein, GGT and LDH were much higher, while neutrophil count was much lower in autumn compared with spring critical-form pregnant patients. (4) Conclusions: the autumn infection generated more dramatic alterations than the spring infection in pregnant patients with critical forms of COVID-19. Larger studies with more numerous participants are required to confirm these results.

Vaccine Protection Through Placenta and Breastfeeding: The Unmet Topic in COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) pandemic has turned pregnant women's healthcare into a worldwide public health challenge. Although initial data did not demonstrate pregnancy as a more susceptible period to severe outcomes of acute severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) infection, there are an increasing number of reports showing that not only pregnant women might be at significantly higher risk than non-pregnant women by COVID-19 but also the fetus. These findings may be related to adaptive changes that occur during pregnancy, such as the reduction in the residual respiratory capacity, the decrease in viral immune responses, and the increased risk for thromboembolic events. Additionally, despite the SARS-CoV-2 vertical transmission evidence being uncommon, maternal illness severity might reflect serious perinatal and neonatal outcomes. Thus, protecting the maternal-fetal dyad against COVID-19 is critical. Even though pregnant women initially were excluded from vaccine trials, several studies have provided safety and efficacy of the overall vaccine COVID-19 platforms. Vaccination during pregnancy becomes a priority and can generate benefits for both the mother and newborn: maternal neutralizing antibodies are transmitted through the placenta and breastfeeding. Moreover, regarding passive immunization, human milk contains other bioactive molecules and cells able to modulate the newborn's immune response, which can be amplified after the vaccine. Nonetheless, many issues remain to be elucidated, considering the magnitude of the protective immunity transferred, the duration of the induced immunity, and the optimal interval for pregnant immunization. In this review, we assessed these unmet topics supported by literature evidence regarding the vaccine's immunogenicity, pregnancy immune heterogeneity, and the unique human milk antiviral features.

The effect of the delta SARS-CoV-2 variant on maternal infection and pregnancy

A greater proportion of pregnant women with COVID-19 have mild disease compared with their non-pregnant counterparts. Paradoxically, however, they are at higher risk of developing severe disease, requiring respiratory support and admission to intensive care. The delta SARS-Cov-2 variant is associated with increased risk of hospitalization and morbidity in unvaccinated pregnant populations. However, it is not known whether the worse pregnancy outcomes associated with the delta variant are due to a direct effect of the virus on the pregnancy, or whether this effect is mediated through more severe maternal infection. Here, we synthesize studies of COVID-19 pregnancies, focusing on the different routes of SARS-CoV-2 infection of lung and placenta, and the mechanisms of syncytial formation for each SARS-CoV-2 variant. To delineate COVID-19 complications in pregnant women, future studies should explore whether the delta variant causes greater placental infection compared to other variants and contributes to increased syncytial formation.

Effects of SARS-CoV-2 Variants on Maternal Infection and Severity: A Single-Center Experience

Background and aims

Pregnant women are one of the vulnerable groups affected by COVID-19. With the mutation of the virus, the severity of the disease in this vulnerable group may vary in different waves of COVID-19 subtypes. The aim of this study is to define the demographic, clinical, laboratory, and mortality results of pregnant COVID-19 patients according to three time frames (March to December 2020, January to June 2021, and July to November 2021).

Materials and methods

The data of patients admitted to the ICU between March 23, 2020, and November 30, 2021, were retrospectively scanned. Pregnant patients with SARS-CoV-2 PCR test positivity or pregnant patients with COVID-19 who have a negative PCR test but symptoms of COVID-19 and radiological findings consistent with COVID-19 on thorax CT who need intensive care were included in the study. The patients were divided into three groups according to the dates when the Ministry of Health of the Republic of Turkey reported the variants of COVID-19 in Turkey. The nonvariant type was dominant in the first period (March to December 2020), alpha and beta variants were dominant in the second period (January to June 2021), and the delta variant appeared in the last period (July to November 2021). Demographic, clinical, and laboratory findings at the first admission to the ICU and mortality rates of the patients were recorded.

Results

PCR test was performed in all 109 patients, of whom 101 were PCR test positive. In other eight patients, despite the negative PCR test, thorax CT findings were typical of COVID-19 pneumonia, and other bacterial and viral agents were also excluded. The mean age of the patients was 30.53 years, the mean APACHE II score was 9.68, and the mean gestational age was 28.55 weeks. Around 72.5% of the patients were in the third trimester. Of the 101 PCR-positive patients, 20.2% were delta variants, 16.5% alpha or beta variants, and 63.3% were of unknown variants. Five of the patients were vaccinated. The most common symptom was dyspnea (94.5%), and the most common comorbidity was hypothyroidism (9.17%). Invasive mechanical ventilation (IMV) was needed in 44.95% of pregnant patients. The distribution of pregnant patients admitted to the ICU according to the periods March to December 2020, January to June 2021, and July to November 2021 was 16.5%, 21.1%, and 62.4%, respectively (p<0.001). Two groups of patients were compared: those that survived versus those that deceased. Variables predicting mortality were APACHE score, IMV requirement, length of stay in the ICU, prone positioning, Anakinra treatment, and ECMO (extracorporeal membrane oxygenator) requirement, which were significantly higher in the deceased group than in the living group (p<0.001, p<0.001, p=0.001, p<0.001, p<0.001, and p=0.001, respectively). There was no significant difference between the patients' age, gestational age, variants, treatments other than Anakinra, and the number of patients admitted to the ICU in the three periods (p=0.667, p=0.174, p=0.904, and p=0.605, respectively).In the multiple logistic regression analysis for mortality, high APACHE II score and IMV requirement were found as risk factors for mortality.

Conclusion

In the last period of delta variant predominance, pregnant COVID-19 patients were admitted to the ICU significantly more frequently than in the first two periods. Mechanical ventilation requirement and high APACHE II score were determined as risk factors for mortality.

Severe COVID-19 during pregnancy treated with pulse corticosteroid therapy and mid-trimester termination: A case report

Background

At the early stage of the pandemic, severe COVID-19 was thought to be rare among pregnant women. However, cumulating data showed that gestational state is a risk factor for severe pneumonia, particularly due to the hyperinflammatory state. Recent reports suggested the efficacy of pulse corticosteroids in stopping the cytokine storm in people infected with SARS-CoV-2, but limited data exists regarding its use in pregnant women. Moreover, pregnancy termination is a treatment option in this population, but it has been reported mainly in the third trimester and rarely in the second trimester.

Case Presentation

A 37-year-old woman infected with SARS-CoV-2 at 23 weeks of gestation presented with fatigue and dyspnea but soon deteriorated to severely acute respiratory failure and cytokine storm requiring mechanical ventilation combined with hemodialysis just one day after hospitalization. Low-dose corticosteroids and antibiotics were initiated, followed by antiviral therapy, anticoagulant and high-dose corticosteroid therapy. On hospital day 3, a decision to terminate her pregnancy was made; termination led to significant improvement in her clinical condition and a gradual decrease in demand for oxygen supplementation as well as the corticosteroid dose. She was discharged two weeks after admission.

Conclusions

Due to the specific immune response, pregnant women with COVID-19 may differ from others in their clinical presentation, especially the probability of classic acute respiratory distress syndrome (ARDS). This report provides evidence related to the efficacy of pulse corticosteroids on this group and the influence of the mid-trimester termination on recovery.

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COVID-19 pneumonia can present as acute respiratory distress syndrome in pregnancy.

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Successful treatment of COVID-19 pneumonia with pulse corticosteroids and mid-trimester medical abortion is reported.

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The case highlights the need for prompt multidisciplinary team management.

Overview of Memory NK Cells in Viral Infections: Possible Role in SARS-CoV-2 Infection

NK cells have usually been defined as cells of the innate immune system, although they are also involved in adaptative responses. These cells belong to the innate lymphocyte cells (ILC) family. They remove unwanted cells, tumoral cells and pathogens. NK cells are essential for viral infection clearance and are involved in tolerogenic responses depending on the dynamic balance of the repertoire of activating and inhibitory receptors. NK plasticity is crucial for tissue function and vigilant immune responses. They directly eliminate virus-infected cells by recognising viral protein antigens using a non-MHC dependent mechanism, recognising viral glycan structures and antigens by NCR family receptors, inducing apoptosis by Fas-Fas ligand interaction, and killing cells by antibody-dependent cell cytotoxicity via the FcγIII receptor. Activating receptors are responsible for the clearance of virally infected cells, while inhibitory KIR receptor activation impairs NK responses and facilitates virus escape. Effective NK memory cells have been described and characterised by a low NKG2A and high NKG2C or NKG2D expression. NK cells have also been used in cell therapy. In SARS-CoV-2 infection, several contradicting reports about the role of NK cells have been published. A careful analysis of the current data and possible implications will be discussed.