Publications by authors named "Esther Oiknine Djian"

Congenital cytomegalovirus (cCMV) is the most common intrauterine infection, leading to neurodevelopmental disabilities. Universal newborn infant screening of cCMV has been increasingly advocated. In the absence of a high-throughput screening test, which can identify all infected newborn infants, the development of an accurate and efficient testing strategy has remained an ongoing challenge.

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Article Synopsis
  • Congenital cytomegalovirus (cCMV) is a major cause of neurodevelopmental disabilities in infants, highlighting the need for better prevention strategies.
  • Researchers studied human CMV infection in decidual tissues from women with and without immunity, finding that those with preconception immunity show resistance to the virus and stimulate specific immune cells upon reinfection.
  • The study suggests that enhancing the immune response in decidual tissues could help develop a vaccine for cCMV and improve understanding of immune defenses at the maternal-fetal interface.
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Intramuscularly administered vaccines stimulate robust serum neutralizing antibodies, yet they are often less competent in eliciting sustainable "sterilizing immunity" at the mucosal level. Our study uncovers a strong temporary neutralizing mucosal component of immunity, emanating from intramuscular administration of an mRNA vaccine. We show that saliva of BNT162b2 vaccinees contains temporary IgA targeting the receptor-binding domain (RBD) of severe acute respiratory syndrome coronavirus-2 spike protein and demonstrate that these IgAs mediate neutralization.

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Background: To minimize COVID-19 pandemic burden and spread, 3-dose vaccination campaigns commenced worldwide. Since patients who are pregnant are at increased risk for severe disease, they were recently included in that policy, despite the lack of available evidence regarding the impact of a third boosting dose during pregnancy, underscoring the urgent need for relevant data. We aimed to characterize the effect of the third boosting dose of mRNA Pfizer BNT162b2 vaccine in pregnancy.

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  • - SARS-CoV-2 Omicron variant shows reduced clinical severity, prompting research into how its interactions with the respiratory tract affect this difference in pathogenicity.
  • - In lab tests with human nasal and lung tissues, Omicron's replication in lung tissues is much more restricted compared to Delta and earlier variants, while remaining similar in nasal tissues.
  • - Omicron triggers a stronger antiviral interferon response in lung tissues than Delta and earlier variants, suggesting that this enhanced immune response contributes to its lower severity; blocking this immune response can allow greater replication of Omicron in lungs.
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COVID-19 is caused by SARS-CoV-2, several virulent variants of which have emerged since 2019. More than 529 million people have been infected, and at least 6 million have died. Our aim was to develop a fast, accurate, low-cost method for detecting and identifying newly emerging variants of concern (VOCs) that could pose a global threat.

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Background: SARS-CoV-2 infection during early infancy can result in severe disease. We evaluated the durability of maternally-derived anti-SARS-CoV-2 antibodies in infants and its relation to antenatal vaccination timing.

Methods: Sera were prospectively collected at birth and 3 months after delivery from mother-infant pairs following antenatal BNT162b2 vaccination.

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Background: Much remains unknown regarding the response of the immune system to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination.

Methods: We employed circulating cell-free DNA (cfDNA) to assess the turnover of specific immune cell types following administration of the Pfizer/BioNTech vaccine.

Findings: The levels of B cell cfDNA after the primary dose correlated with development of neutralizing antibodies and memory B cells after the booster, revealing a link between early B cell turnover-potentially reflecting affinity maturation-and later development of effective humoral response.

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We evaluated the neutralization efficiency against SARS-CoV-2 Omicron variant in maternal and cord blood sera after antenatal BNT162b2 vaccination. Neutralizing antibodies against Omicron were lacking at the time of delivery after 2-dose vaccination. A third booster dose was essential in building neutralizing antibody capacity against Omicron among mothers and neonates.

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BACKGROUNDCytomegalovirus (CMV) is the most common intrauterine infection, leading to infant brain damage. Prognostic assessment of CMV-infected fetuses has remained an ongoing challenge in prenatal care, in the absence of established prenatal biomarkers of congenital CMV (cCMV) infection severity. We aimed to identify prognostic biomarkers of cCMV-related fetal brain injury.

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Background: Post-COVID-19 vaccine boosting is a potent tool in the ongoing pandemic. Relevant data regarding this approach during pregnancy are lacking, which affects vaccination policy guidance, public acceptance, and vaccine uptake during pregnancy. We aimed to investigate the dynamics of anti-SARS-CoV-2 antibody levels following SARS-CoV-2 infection during pregnancy and to characterize the effect of a single postinfection vaccine booster dose on the anti-SARS-CoV-2 antibody levels in parturients in comparison with the levels in naïve vaccinated and convalescent, nonboosted parturients.

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The introduction of a third-dose vaccination along with new variants of concern raises questions regarding serology and T-cell responses in patients with multiple sclerosis (pwMS) treated with B-cell depletion who develop attenuated humoral response to vaccines. The aim of this study was to longitudinally evaluate humoral and cellular response to SARS-CoV-2 mRNA vaccine in ocrelizumab-treated pwMS before and following a third vaccine dose. Following the third vaccine dose, patients who are low or nonresponders following initial vaccination did not increase antibody titers.

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Background: Coronavirus disease 2019 (COVID-19) during pregnancy and early infancy can result in severe disease. Evaluating the effect of gestational age at the time of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on maternal antibody levels and transplacental antibody transfer has important implications for maternal care and vaccination strategies.

Methods: Maternal and cord blood sera were collected from mother-newborn dyads (n = 402), following term delivery after antenatal 2-dose SARS-CoV-2 BNT162b2 mRNA vaccination.

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Background: Determining the humoral immunogenicity of tozinameran (BNT162b2) in patients requiring chronic renal replacement therapy, and its impact on COVID-19 morbidity several months after vaccination, may guide risk assessment and changes in vaccination policy.

Methods: In a prospective post-vaccination cohort study with up to 5 months follow-up we studied outpatient dialysis and kidney transplant patients and respective healthcare teams. Outcomes were anti S1/S2 antibody responses to vaccine or infection, and infection rate during follow-up.

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This cohort study evaluates the short-term humoral response to a third dose of the SARS-CoV-2 BNT162b2 vaccine in patients undergoing acute systemic therapy for solid tumors.

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Objective: We aimed to assess the impact of early versus late third-trimester maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on transplacental transfer and neonatal levels of SARS-CoV-2 antibodies.

Methods: Maternal and cord blood sera were collected following term delivery after antenatal SARS-CoV-2 BNT162b2 mRNA vaccination, with the first vaccine dose administered between 27 and 36 weeks of gestation. SARS-CoV-2 spike protein (S) and receptor-binding domain (RBD) -specific, IgG levels and neutralizing potency were evaluated in maternal and cord blood samples.

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Most severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic tests have relied on RNA extraction followed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays. Whereas automation improved logistics and different pooling strategies increased testing capacity, highly multiplexed next-generation sequencing (NGS) diagnostics remain a largely untapped resource. NGS tests have the potential to markedly increase throughput while providing crucial SARS-CoV-2 variant information.

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Importance: B-cell-depleting therapies may affect the development of a protective immune response following vaccination. Understanding the ability to develop vaccine-specific immunity to COVID-19 in patients with multiple sclerosis (MS) treated with B-cell-depleting therapy is of importance for clinical decisions.

Objective: To assess SARS-CoV-2 vaccine-specific humoral and cellular responses in patients treated with ocrelizumab compared with healthy controls.

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Article Synopsis
  • Natural killer (NK) cells are immune cells that can kill infected cells without needing prior exposure, with the NKG2D receptor being vital for their activation by binding ligands like MICA.
  • Human cytomegalovirus (HCMV) can evade NK cell responses by producing proteins that inhibit MICA, an important ligand for NK cell activation, with the US9 protein specifically targeting the MICA*008 allele.
  • Researchers have discovered a new HCMV protein, UL147A, which not only downregulates MICA*008 but also prevents its proper maturation and promotes its degradation, further enhancing HCMV's ability to avoid detection by NK cells.
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  • The nasal mucosa is the main entry point for respiratory viruses like SARS-CoV-2, but its early immune responses during infection have been largely overlooked.
  • Research used human nasal and lung tissues to analyze how these sites respond to SARS-CoV-2 compared to influenza, revealing that the nasal mucosa mounts a strong antiviral response while lung tissues show a much weaker reaction.
  • These findings indicate that targeting the nasal mucosa could be crucial for early intervention during SARS-CoV-2 infection, potentially preventing severe lung damage seen in advanced COVID-19 cases.
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Maternal and cord blood sera were collected from 20 parturients who received the BNT162b2 vaccine. All women and infants were positive for anti S- and anti-receptor binding domain antibody-specific immunoglobulin G. Cord blood antibody concentrations were correlated to maternal levels and to time since vaccination.

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Conducting numerous, rapid, and reliable PCR tests for SARS-CoV-2 is essential for our ability to monitor and control the current COVID-19 pandemic. Here, we tested the sensitivity and efficiency of SARS-CoV-2 detection in clinical samples collected directly into a mix of lysis buffer and RNA preservative, thus inactivating the virus immediately after sampling. We tested 79 COVID-19 patients and 20 healthy controls.

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Pooling multiple swab samples before RNA extraction and real-time reverse transcription polymerase chain reaction (RT-PCR) analysis has been proposed as a strategy to reduce costs and increase throughput of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tests. However, reports on practical large-scale group testing for SARS-CoV-2 have been scant. Key open questions concern reduced sensitivity due to sample dilution, the rate of false positives, the actual efficiency (number of tests saved by pooling), and the impact of infection rate in the population on assay performance.

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