Transplacental transfer of anti-SARS-CoV-2 neutralizing antibodies in comparison to other pathogens total antibodies.

BACKGROUNDS: Due to immaturity of their immune system, passive maternal immunization is essential for newborns during their first months of life. Therefore, in the current context of intense circulation of SARS-CoV-2, identifying factors influencing the transfer ratio (TR) of neutralizing antibodies against SARS-CoV-2 (NAb) appears important. METHODS: Our study nested in the COVIPREG cohort (NCT04355234), included mothers who had a SARS-CoV-2 PCR positive during their pregnancy and their newborns. Maternal and neonatal NAb levels were measured with the automated iFlash system. RESULTS: For the 173 mother-infant pairs included in our study, the median gestational age (GA) at delivery was 39.4 weeks of gestation (WG), and 29.7 WG at maternal SARS-CoV-2 infection. Using a multivariate logistic model, having a NAb TR above 1 was positively associated with a longer delay from maternal positive SARS-CoV-2 PCR to delivery (aOR 1.09, 95% CI: 1.03 - 1.17) and with a later GA at delivery (aOR = 1.58, 95% CI: 1.09 - 2.52). It was negatively associated with being a male newborn (aOR 0.21, 95% CI: 0.07 - 0.59). In 3rd trimester SARS-CoV-2 infected mothers, NAb TR was inferior to VZV, toxoplasmosis, CMV, measle and rubella's TR. However, in 1st or 2nd trimester infected mothers, only measle TR was different from NAb TR. CONCLUSION: Male newborn of mothers infected by SARS-CoV-2 during their pregnancy appear to have less protection against SARS-CoV-2 in their first months of life than female newborns. Measle TR was superior to NAb TR even in case of 1st or 2nd trimester maternal SARS-CoV-2 infection. Future studies are needed to investigate possible differences in transmission of NAb following infection vs vaccination and its impact on TR.

Transmission of SARS-CoV-2 from mother to fetus or neonate: what to know and what to do?

SARS-CoV-2 can be vertically transmitted from the mother to the fetus and the neonate. This transmission route is rare compared to the environmental or horizontal spread and therefore, the risk can be deemed inconsequential by some medical providers. However, severe, although just as rare, feto-neonatal consequences are possible: fetal demise, severe/critical neonatal COVID-19 and multi-inflammatory syndrome (MIS-N) have been described. Therefore, it is important for the clinicians to know the mechanism of vertical transmission, how to recognize this vector, and how to deal with neonatal COVID-19 and MIS-N. Our knowledge about this field has significantly increased in the last three years. This is a summary of the pathophysiology, diagnostics, and therapeutics of vertical SARS-CoV-2 transmission that clinicians to apply in their clinical practice.

Transmission of SARS-CoV-2 from mother to fetus or neonate: What to know and what to do?

SARS-CoV-2 can be vertically transmitted from the mother to the fetus and the neonate. This transmission route is rare compared to the environmental or horizontal spread and therefore, the risk can be deemed inconsequential by some medical providers. However, severe, although just as rare, feto-neonatal consequences are possible: fetal demise, severe/critical neonatal COVID-19 and multi-inflammatory syndrome (MIS-N) have been described. Therefore, it is important for the clinicians to know the mechanism of vertical transmission, how to recognize this, and how to deal with neonatal COVID-19 and MIS-N. Our knowledge about this field has significantly increased in the last three years. This is a summary of the pathophysiology, diagnostics, and therapeutics of vertical SARS-CoV-2 transmission that clinicians apply in their clinical practice.

Nasopharyngeal SARS-CoV-2 load and perinatal outcomes after maternal infection diagnosed close to delivery.

BACKGROUND: The occurrence of COVID-19 during the pregnancy can cause several negative maternal and neonatal outcomes. Nasopharyngeal viral load is associated with inflammatory markers and might influence the disease severity in non-pregnant patients, but there are no data about the relationship between viral load and perinatal outcomes in pregnant patients. OBJECTIVE: To investigate the hypothesis that nasopharyngeal SARS-CoV-2 load (estimated with real-time polymerase chain reaction delta cycle (ΔCt), measured in hospital clinical laboratories) is associated with perinatal outcomes, when COVID-19 is diagnosed in the third trimester of pregnancy. STUDY DESIGN: International, retrospective, observational, multi-center, cohort study enrolling 390 women (393 neonates, three pairs of twins), analyzed with multivariate generalized linear models with skewed distributions (gamma) and identity link. The analyses were conducted for the whole population and then followed by a subgroup analysis according to the clinical severity of maternal COVID-19. RESULTS: The estimated viral load in maternal nasopharynx is not significantly associated with gestational age at birth (adjusted B: -0.008 (95%CI: -0.04; 0.02); p = 0.889), birth weight (adjusted B: 4.29 (95%CI: -25; 35); p = 0.889), weight Z-score (adjusted B: -0.01 (95%CI: -0.03; 1); p = 0.336), 5' Apgar scores (adjusted B: -0. -9.8e-4 (95%CI: -0.01; 0.01); p = 0.889), prematurity (adjusted OR: -0.97 (95%CI: 0.93; 1.03); p = 0.766) and the small for gestational age status (adjusted OR: 1.03 (95%CI: 0.99; 1.07); p = 0.351). Similar results were obtained in subgroup analyses according to COVID-19 clinical severity. CONCLUSIONS: The estimated maternal nasopharyngeal viral load in pregnant women affected by COVID-19 during the third trimester is not associated with main perinatal outcomes.

Validation of a SARS-CoV-2 Surrogate Virus Neutralization Test in Recovered and Vaccinated Healthcare Workers.

Vaccination against COVID-19 is the main public health approach to fight against the pandemic. The Spike (S) glycoprotein of SARS-CoV-2 is the principal target of the neutralizing humoral response. We evaluated the analytical and clinical performances of a surrogate virus neutralization test (sVNT) compared to conventional neutralization tests (cVNTs) and anti-S eCLIA assays in recovered and/or vaccinated healthcare workers. Our results indicate that sVNTs displayed high specificity and no cross-reactivity. Both eCLIA and sVNT immunoassays were good at identifying cVNT serum dilutions ≥1:16. The optimal thresholds when identifying cVNT titers ≥1:16, were 74.5 U/mL and 49.4 IU/mL for anti-S eCLIA and sVNT, respectively. Our data show that neutralizing antibody titers (Nab) differ from one individual to another and may diminish over time. Specific assays such as sVNTs could offer a reliable complementary tool to routine anti-S serological assays.

Systematic review and synthesis of stillbirths and late miscarriages following SARS-CoV-2 infections.

OBJECTIVE: This study aimed to describe the characteristics of fetal demise after SARS-CoV-2 infections and clarify whether it is associated with clinical severity, placental lesions, or malformations or due to actual fetal infections. DATA SOURCES: PubMed and Web of Science databases were searched between December 1, 2019, and April 30, 2022. STUDY ELIGIBILITY CRITERIA: Cohort, cross-sectional, and case-control studies and case series or case reports describing stillbirths or late miscarriages (ie, pregnancy loss occurring between 14 and 22 weeks of gestation, before and after the onset of labor) from mothers with SARS-CoV-2 infection during pregnancy (demonstrated by at least 1 positive real-time reverse transcription-polymerase chain reaction from nasopharyngeal swabs and/or SARS-CoV-2 placental infection). No language restriction was applied; cases with other causes possibly explaining the fetal demise were excluded. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analysis Of Observational Studies in Epidemiology guidelines were followed. The quality of the case series and case reports was evaluated using the specific Mayo Clinic Evidence-Based Practice Center tool. Maternal and clinical fetal data and placental and fetal virology and histology findings were collected. Data were summarized with descriptive statistics using the World Health Organization criteria to classify disease severity and fetal-neonatal infections. RESULTS: Data from 184 mothers and 190 fetuses were analyzed. No clear link to maternal clinical severity or fetal malformation was evident. Approximately 78% of fetal demise cases occurred during the second and third trimesters of pregnancy, approximately 6 to 13 days after the diagnosis of SARS-CoV-2 infection or the onset of symptoms. Most placentas (88%) were positive for SARS-CoV-2 or presented the histologic features of placentitis (massive fibrin deposition and chronic intervillositis) previously observed in transplacentally transmitted infections (85%-91%). Of note, 11 fetuses (5.8%) had a confirmed in utero transmitted SARS-CoV-2 infection, and 114 fetuses (60%) had a possible in utero transmitted SARS-CoV-2 infection. CONCLUSION: The synthesis of available data showed that fetal demise generally occurs a few days after the infection with histologic placental inflammatory lesions associated with transplacental SARS-CoV-2 transmission and eventually causing placental insufficiency.

Conjunctival carriage of SARS-CoV-2 in asymptomatic and non-severe symptomatic COVID-19 patients Portage conjonctival du SARS-CoV-2 chez les patients atteints de formes asymptomatiques ou non sévères de COVID-19 (COVIDEYE)

Introduction: The prevalence of ocular conveyance of SARS-CoV-2 has been well described for severe/hospitalized cases, but scarcely reported in asymptomatic and non-severe patients, who are unaware that they are carriers. Material & Methods: This prospective cross-sectional study quantitatively evaluated SARS-CoV-2 shedding on the ocular surface (OS). Conjunctival testing was suggested to all hospital personnel being screened by nasopharyngeal (NP) SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR). Disease symptoms were evaluated using a standardized questionnaire and telephone follow-up 6 ± 3 months later for disease evolution (recovery with/without severe disease). Results: 487 patients were included. From 46 NP SARS-CoV-2-positive subjects (cycle threshold (CT) = 24.2 ± 7.1), 13% tested positive at the OS (CT = 36.4 ± 2.8). Most SARS-CoV-2-positive subjects were symptomatic (N = 40, 87%), while 6 were asymptomatic (being tested as contact cases). Systemic symptoms were not significantly different in OS-positive vs OS-negative subjects, although headache tended to be more frequent in OS-positives (83% vs 54%, p = 0.06). None of the OS-positive subjects reported ocular symptoms, and none developed severe disease requiring hospitalization or oxygen therapy. Conclusion: SARS-CoV-2 shedding at the OS may occur in asymptomatic and non-severe COVID-19 individuals (including those absent of ocular symptoms). However, the high RT-PCR CT values attained may indicate a low risk of transmissibility via this route.

Persistence of Neutralizing Antibodies and Clinical Protection up to 12†Months After Severe Acute Respiratory Syndrome Coronavirus 2 Infection in the Elderly.

Background: Coronavirus disease 2019 (COVID-19) has severely affected the elderly, who are expected to display decreased immune responses due to immunosenescence. Methods: This study retrospectively assesses neutralizing antibody (NAb) production up to 12 months after infection in long-term care patients. We used Roche Diagnostics immunoassay to quantify anti-spike (S) antibodies and a competitive immunoassay from YHLO as a surrogate test for NAb. Results: We included 91 patients (mean age, 86 years). There was no significant variation in anti-S titers over time. There was a significant decrease of NAb titers between month 3 and month 6 but no further significant change up to month 12. Overall, 75 of 91 (82%) and 52 of 91 (57%) patients had, at least once, anti-S titers >75 U/mL and NAb titers >50 AU/mL, respectively, corresponding to a significant neutralizing activity in vitro. All 68 patients studied at M12 had detectable anti-S antibodies and 60 (88%) had detectable NAb; 60 of 68 (88%) and 29 of 68 (42.6%) still had anti-S titers >75 U/mL and NAb titers >50 AU/mL. Higher NAb titers were correlated with severe infection, higher levels of C-reactive protein, and lower lymphocyte counts. No patient developed reinfection. Conclusions: Elderly people can display robust and persistent humoral response after severe acute respiratory syndrome coronavirus 2 infection, with NAb lasting up to 12 months.

The Essentials about Neonatal Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Coronavirus Disease: A Narrative Review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can occur in neonates as the virus can be transmitted both horizontally (from the environment) and vertically (during the pregnancy or at the delivery). Compared to the adult outbreak, neonatal infections do not represent a public health problem. Nonetheless, severe and life-threatening cases may rarely occur and both obstetricians and neonatologists should have a good knowledge of perinatal SARS-CoV-2 infection and related consequences. A high suspicion index must be applied and ruling out neonatal SARS-CoV-2 infection must become a part of the routine clinical workout. Moreover, neonates may be affected by the multisystem inflammatory syndrome, due to a dysregulated host response in the absence of any SARS-CoV-2 infection. We performed a narrative review to summarize here the available literature describing the essentials that should be known by every neonatologist and obstetrician, starting from what has been discovered in 2020 and adding what has been learned in the following years. The paper describes the mechanisms of transmission, clinical features, diagnostic tools, and criteria, as well as possible treatment and prevention strategies. The goal is to provide the practical points to be remembered at the bedside while caring for a pregnant woman or a neonate with suspected or proven coronavirus disease 2019 or multisystem inflammatory syndrome. KEY POINTS: · SARS-CoV-2 neonatal infections occur both vertically (30%) and horizontally (70%).. · Approximately, half of patients do not have clinical manifestations; clinical and laboratory signs are similar to those of adults but usually milder.. · Remdesivir and steroids can be used as a treatment..

Clinical Added Value of SARS-CoV-2 Antigen Detection in Blood Samples.

This study evaluated the performances of immunoassays (LFIA and ELISA) designed for SARS-CoV-2 Antigen (Ag)-detection in nasopharyngeal (NP) and serum samples in comparison to RT-PCR. NP samples from patients with respiratory symptoms (183 RT-PCR-positive and 74 RT-PCR-negative samples) were collected from March to April and November to December 2020. Seroconversion and antigen dynamics were assessed by symptom onset and day of RT-PCR diagnosis. Serum samples from 87 COVID-19 patients were used to investigate the added value of Ag quantification, at diagnosis and during follow-up. The sensitivity of COVID-VIRO-LFIA on samples with Ct ≤ 33, considered as the contagious threshold, was 86% on NPs (CI 95%: 79-90.5) and 76% on serum samples (CI 95%: 59.4-88), with a specificity of 100%. Serum N-Ag was detected during active infection as early as day two from symptom onset, with a diagnostic sensitivity of 81.5%. Within one week of symptom onset, diagnostic sensitivity and specificity reached 90.9% (95% CI, 85.1%-94.6%) and 98.3% (95% CI, 91.1%-99.9%), respectively. Serum N-Ag concentration closely correlated with disease severity. Longitudinal analysis revealed the simultaneous increase of antibodies and decrease of N-Ag. Sensitivities of COVID-VIRO-LFIA and COV-QUANTO-ELISA tests on NP and serum samples were close to 80%. They are suitable COVID-19-laboratory diagnostic tests, particularly when blood samples are available, thus reducing the requirement for NP sampling, and subsequent PCR analysis. ELISA titers may help to identify patients at risk of poor outcomes.

Impact of SARS-CoV-2 Alpha and Gamma Variants among Symptomatic Pregnant Women: A Two-Center Retrospective Cohort Study between France and Brazil.

New variants of SARS-CoV-2 are a major source of concern, especially for pregnant women and in the perinatal context. The primary aim of this study was to compare the severity of COVID-19 infection in pregnant women depending on strain predominance between wild-type Alpha and Gamma variants. The secondary aim was to study the impact of these strains on obstetrical and neonatal outcomes. We conducted a two-center international retrospective cohort study, which included two type III maternity hospitals, one in France and one in Brazil, comparing the first period corresponding to the wild-type strain and the second period corresponding to the predominance of the Alpha variant in France and the Gamma variant in Brazil. We included 151 pregnant women with symptomatic SARS-CoV-2 infection confirmed by RT-PCR. The rate of severe-to-critical infection, according to the WHO definition, was seven-fold higher in patients infected during the "variant period" than in patients infected during the "wild-type period" (aOR = 7.07, 95CI [2.50-21.6], p < 0.001). There were no statistical differences concerning composite obstetrical and neonatal outcomes between the different periods. While analyzing each variant separately, it was found that, in France, the risk of developing a severe-to-critical infection was three times greater during the Alpha period than during the wild-type period (OR = 3.25, 95CI [0.70-15.6], p = 0.13) and, in Brazil, the risk was twelve times greater during the Gamma period than during the wild-type period (OR = 11.8, 95CI [2.46-72.3], p = 0.003). The Alpha and Gamma variants of SARS-CoV-2 seem to be more dangerous in the obstetrical context. With the rapid emergence of new variants, it is necessary to accelerate vaccination to protect women and newborn children.

Rituximab Impairs B Cell Response But Not T Cell Response to COVID-19 Vaccine in Autoimmune Diseases.

OBJECTIVE: Antibody response to the messenger RNA (mRNA) COVID-19 vaccine has been shown to be diminished in rituximab (RTX)-treated patients. We undertook this study to compare humoral and T cell responses between healthy controls, patients with autoimmune diseases treated with RTX, and those treated with other immunosuppressants, all of whom had been vaccinated with 2 doses of the mRNA COVID-19 vaccine. METHODS: We performed anti-spike IgG and neutralization assays just before and 28 days after the second BNT162b2 (Pfizer-BioNTech) vaccine dose. The specific T cell response was assessed in activated CD4 and CD8 T cells using intracellular flow cytometry staining of cytokines (interferon-γ, tumor necrosis factor, and interleukin-2) after stimulation with SARS-CoV-2 spike peptide pools. RESULTS: A lower proportion of responders with neutralizing antibodies to the vaccine was observed in the RTX group (29%; n = 24) compared to the other immunosuppressants group (80%; n = 35) (P = 0.0001) and the healthy control group (92%; n = 26) (P < 0.0001). No patients treated with RTX in the last 6 months showed a response. Time since last infusion was the main factor influencing humoral response in RTX-treated patients. The functional CD4 and CD8 cellular responses to SARS-CoV-2 peptides for each single cytokine or polyfunctionality were not different in the RTX group compared to the other immunosuppressants group or the control group. In RTX-treated patients, the T cell response was not different between patients with and those without a humoral response. CONCLUSION: RTX induced a diminished antibody response to the mRNA COVID-19 vaccine, but the functional T cell response was not altered compared to healthy controls and autoimmune disease patients treated with other immunosuppressants. Further work is needed to assess the clinical protection granted by a functionally active T cell response in the absence of an anti-spike antibody response.

Pregnant women's perceptions of the COVID-19 vaccine: A French survey.

INTRODUCTION: Pregnant women are at increased risk for COVID-19, and COVID-19 vaccine is the most promising solution to overcome the current pandemic. This study was conducted to evaluate pregnant women's perceptions and acceptance of COVID-19 vaccination. MATERIALS & METHODS: A cross-sectional study was conducted from February 18 to April 5 2021. An anonymous survey was distributed in 7 French obstetrics departments to all pregnant women before a prenatal visit. All pregnant women attending a follow-up consultation were asked to participate in the study. An anonymous web survey was available through a QR code and participants were asked whether or not they would agree to be vaccinated against SARS-CoV-2, and why. The questionnaire included questions on the patients' demographics and their knowledge of COVID-19 vaccines. RESULTS: Of the 664 pregnant women who completed the questionnaire, 29.5% (95% CI 27.7; 31.3) indicated they would agree to be vaccinated against COVID-19. The main reason for not agreeing was being more afraid of potential side effects of the SARS-CoV-2 vaccine on the fetus than of COVID-19. Factors influencing acceptance of vaccination were: being slightly older, multiparity, having discussed it with a caregiver and acceptance of the influenza vaccine. DISCUSSION: Nearly one-third of pregnant women in this population would be willing to be vaccinated. In addition to studies establishing fetal safety, public health agencies and healthcare professionals should provide accurate information about the safety of COVID-19 vaccines.

Emergence of SARS-CoV-2 resistance mutations in a patient who received anti-SARS-COV2 spike protein monoclonal antibodies: a case report.

BACKGROUND: To manage severe or potentially severe cases of CoronaVirus Disease 2019 (COVID-19), therapeutic monoclonal antibodies targeting Spike protein of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) have been designed. It has been noted in vitro that upon exposure to these treatments, mutations could be selected. CASE PRESENTATION: We here report the case of an immunosuppressed patient infected with a B.1.1.7 variant, who received a combination of monoclonal antibodies, and subsequently selected mutations K417N, E484K and Q493R on Spike protein of SARS-CoV-2. CONCLUSIONS: Our case raises the importance of monitoring SARS-CoV-2 mutations in patients receiving monoclonal antibodies and having persistent excretion of the virus, in order to offer optimal management of their infection, and strengthen prevention measures to avoid subsequent transmission of these selected variants.

Retrospective Description of Pregnant Women Infected with Severe Acute Respiratory Syndrome Coronavirus 2, France

Little data are available on the management of pregnant women infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We conducted a retrospective study of 100 pregnant women with SARS-CoV-2 infection in 4 obstetric units in the Paris metropolitan area of France during March 12-April 13, 2020. Among patients, 52 (52%) were hospitalized, 10 (10%) in intensive care units (ICUs). Women with higher body mass indexes (BMIs;median 30.7 kg/m2) were more likely to be hospitalized in ICUs than other women (median BMI 26.2 kg/m2). Women hospitalized in ICUs had lower lymphocyte count at diagnosis (median 0.77 × 109 cells/L) than women not hospitalized in ICUs (median lymphocyte count 1.15 × 109 cells/L). All women requiring oxygen >5 L/min were intubated. Clinical and laboratory evaluation of SARS-CoV-2-positive pregnant women at the time of diagnosis can identify patients at risk for ICU hospitalization.