Publications by authors named "Marc Elsen"

Introduction: Some studies suggest that the monovalent mRNA-1273 vaccine is more effective than BNT162b2 in producing higher levels of antibodies. However, limited data are available, and the methods used are not directly comparable.

Material And Methods: Blood samples were obtained before the booster (third dose) and after 14, 90, and 180 days in two similar cohorts who received the original BNT162b2 or mRNA-1273 vaccine designed to target wild type SARS-CoV-2.

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Studies about the duration of the humoral and cellular response following the bivalent booster administration are still scarce. We aimed at assessing the humoral and cellular response in a cohort of healthcare workers that received this booster. Blood samples were collected before the administration of the bivalent booster from Pfizer-BioNTech and after 14, 28, 90, and 180 days.

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The diagnostic of SARS-CoV-2 infection relies on reverse transcriptase polymerase chain reactions (RT-PCRs) performed on nasopharyngeal (NP) swabs. Nevertheless, false-negative results can be obtained with inadequate sampling procedures, making the use of other biological matrices worthy of investigation. This study aims to evaluate the kinetics of serum N antigens in severe and non-severe patients and compare the clinical performance of serum antigenic assays with NP RT-PCR.

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Objectives: The high request for vitamin D testing in the last decades has led manufacturers to develop assays on automated immunoassay platforms. The objective of this study was to evaluate the performance of the new Elecsys Vitamin D total III assay for the measurement of total 25(OH)D.

Methods: A total of 844 serum samples collected in two clinical laboratories were used to evaluate the new Roche Elecsys Vitamin D total III assay.

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Data about the long-term duration of antibodies after SARS-CoV-2 vaccination are still scarce and are important to design vaccination strategies. In this study, 231 healthcare professionals received the two-dose regimen of BNT162b2. Of these, 158 were seronegative and 73 were seropositive at baseline.

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The evaluation of the neutralizing capacity of anti-SARS-CoV-2 antibodies is important because they represent real protective immunity. In this study we aimed to measure and compare the neutralizing antibodies (NAbs) in COVID-19 patients and in vaccinated individuals. One-hundred and fifty long-term samples from 75 COVID-19 patients were analyzed with a surrogate virus neutralization test (sVNT) and compared to six different SARS-CoV-2 serology assays.

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Several studies reported on the humoral response in subjects having received the BNT162b2 mRNA COVID-19 vaccine. However, data on the kinetics of antibodies 3 months post-vaccination are currently lacking and are important to drive the future vaccination strategy. The CRO-VAX HCP study is an ongoing multicentre, prospective and interventional study designed to assess the antibody response in a population of healthcare professionals who had received two doses of the BNT162b2 mRNA COVID-19 vaccine.

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Background: Little is known about potential confounding factors influencing the humoral response in individuals having received the BNT162b2 vaccine.

Methods: Blood samples from 231 subjects were collected before and 14, 28, and 42 days following coronavirus disease 2019 (COVID-19) vaccination with BNT162b2. Anti-spike receptor-binding-domain protein (anti-Spike/RBD) immunoglobulin G (IgG) antibodies were measured at each time-point.

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Several studies have described the long-term kinetics of anti-SARS-CoV-2 antibodies but long-term follow-up data, i.e., >6 months, are still sparse.

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Following the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, numerous serological tests have been developed, including rapid diagnostic tests. This study aims at assessing the clinical performance of the Panbio immunoglobulin G (IgG)/IgM coronavirus disease 2019 (COVID-19) test (Abbott), a rapid lateral flow assay for the qualitative detection of IgG and IgM against SARS-CoV-2. One hundred and thirty-eight samples from 95 COVID-19 patients with a positive SARS-CoV-2 reverse-transcriptase polymerase chain reaction were analyzed to assess the clinical sensitivity.

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(1) Background: The detection of SARS-CoV-2 RNA in nasopharyngeal samples through real-time reverse transcription-polymerase chain reaction (RT-PCR) is considered the standard gold method for the diagnosis of SARS-CoV-2 infection. Antigen detection (AD) tests are more rapid, less laborious, and less expensive alternatives but still require clinical validation. (2) Methods: This study compared the clinical performance of five AD tests, including four rapid AD (RAD) tests (biotical, Panbio, Healgen, and Roche) and one automated AD test (VITROS).

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Strategies to detect SARS-CoV-2 are increasingly being developed. Among them, serological methods have been developed. Nevertheless, although these may present an interesting clinical performance, they are often directed against only one antigen.

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This study assesses the clinical performance of three anti-SARS-CoV-2 assays, namely EUROIMMUN anti-SARS-CoV-2 nucleocapsid (IgG) ELISA, Elecsys anti-SARS-CoV-2 nucleocapsid (total antibodies) assay, and LIAISON anti-SARS-CoV-2 spike proteins S1 and S2 (IgG) assay. One hundred and thirty-seven coronavirus disease 2019 (COVID-19) samples from 96 reverse-transcription polymerase chain reaction confirmed patients were chosen to perform the sensitivity analysis. Non-SARS-CoV-2 sera (n = 141) with a potential cross-reaction to SARS-CoV-2 immunoassays were included in the specificity analysis.

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Article Synopsis
  • The study evaluates the iFlash® anti-SARS-CoV-2 assay's ability to detect IgM and IgG antibodies and its analytical performance.
  • Analytical tests showed strong performance, with IgG reaching 100% sensitivity 28 days post-symptom onset after cut-off optimization.
  • The findings suggest that while the assay performs well, the IgM detection is less reliable for clinical use compared to IgG, indicating a preference for IgG testing later in the infection.
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