Vaccine-induced humoral response of BNT162b2 and mRNA-1273 against BA.1, BA.5, and XBB.1.5. (sub)variants 6 months after a homologous booster: is immunogenicity equivalent?

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.

Assessment of the neutralizing antibody response in Omicron breakthrough cases in healthcare workers who received the homologous booster of Moderna mRNA-1273.

Vaccines against SARS-CoV-2 were developed during the pandemic including the BNT162b2 and the mRNA-1273. We evaluated the levels of binding antibodies against the receptor binding domain and the levels of NAbs in individuals who developed a breakthrough infection after having received three doses of mRNA-1273. A total of 51 participants were included.

Added value of a connected glucose meter for glycorrhachia assessment.

Objectives: The aim of this study was to demonstrate the performance and added value of rapid glucose determination in cerebrospinal fluid using a connected glucometer.

Design And Methods: Intra-assay and inter-assay accuracies were calculated using residual clinical samples. Accuracies were measured by comparing the results obtained with the glucometer to those from the central laboratory on a large routine chemistry platform.

Clinical evaluation of a dermatophyte RT-PCR assay and its impact on the turn-around-time: A prospective study.

Onychomycosis is an important public health problem whose prevalence continues to grow and impact public health at several levels. Nevertheless, today the main diagnostic methods used in routine practice have many drawbacks. The aim of this study was to evaluate, for the first time, the clinical performance of a new multiplex polymerase chain reaction (PCR) (Novaplex®) in the identification of the causative agent on nail samples, and its impact on the turnaround time, compared to our traditional laboratory methods.

Nursery outbreak caused by enteroaggregative Escherichia coli serogroup O111:H21.

This study describes, for the first time, the occurrence of an epidemic of enteroaggregative Escherichia coli (EAEC) O111:H21 in a Belgian nursery and describes a practical approach concerning its management. Few data exist in the literature on this type of outbreak. Clinical and microbiological investigations were needed to find a link between the cases and identify the causative agent.

Clinical evaluation of the GSD NovaPrime® SARS-CoV-2 RTq-PCR assay.

Faced with the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), high-throughput respiratory tests are in high demand. We evaluated the clinical performance of the GSD NovaPrime® SARS-CoV-2 RTq-PCR assay, a new assay that detects 2 specific RNA sequences of the nucleocapsid (N) gene. It was assessed using 99 nasopharyngeal samples and compared in parallel with the Allplex® assay.

Immunogenicity of mRNA-1273 COVID vaccine after 6 months surveillance in health care workers; a third dose is necessary.

Objectives: Scarce data are currently available on the kinetics of antibodies after vaccination with mRNA vaccines as a whole and, with mRNA-1273, in particular. We report here an ad-interim analysis of data obtained after a 6-month follow-up in a cohort of healthcare workers (HCWs) who received the mRNA-1273 vaccine. These new data provide more insight into whether and in whom a 3rd dose could be necessary.

The challenge of screening SARS-CoV-2 variants of concern with RT-qPCR: One variant can hide another.

Introduction: Following the emergence of SARS-CoV-2 variants of concern (VOCs) worldwide, it is important to monitor local epidemiology to better understand the occurrence of clusters, reinfections, or infection after vaccination. Detecting mutations by specific RT-qPCR is a rapid and affordable alternative to sequencing. However, care must be taken to ensure that the techniques used are up-to-date and adapted to the variants circulating in the studied population.

Efficacy comparison of three rapid antigen tests for SARS-CoV-2 and how viral load impact their performance.

More and more rapid antigen tests for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) appear in the market with varying performance. The sensitivity of these tests heavily depends on the viral load, extrapolated by the threshold cycle (Ct). It is therefore essential to verify their performance before their inclusion in routine.

Clinical performance of the Panbio assay for the detection of SARS-CoV-2 IgM and IgG in COVID-19 patients.

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.

Diagnosis of respiratory syncytial virus and influenza A and B with cobas® Liat® from nasopharyngeal aspirations in pediatrics.

The cobas® Liat® Influenza A/B and respiratory syncytial virus assay was tested on nasopharyngeal aspirates. The resolution of invalid samples was performed using a preanalytical step. cobas® Liat® can be used on nasopharyngeal aspirates with a preanalytical processing step, with a slightly diminished performances in detecting respiratory syncytial virus but not for influenza.

Development and implementation of a RT-qPCR extraction-free protocol for the detection of SARS-CoV-2 and impact on the turn-around-time.

The occurrence of the COVID-19 second-wave outbreak in Europe has pushed laboratories performing molecular SARS-CoV-2 tests to increase their throughput and decrease the result rendering time. In this evaluation, we tested for the first time a new, extraction-free, protocol with the Allplex SARS-CoV-2 Assay RT-qPCR kit on a Nimbus platform. Ninety-one samples, of which 71 previously tested positive with RT-qPCR with extraction were immediately analyzed without extraction, using only a dilution and thermal shock protocol.

An Original ELISA-Based Multiplex Method for the Simultaneous Detection of 5 SARS-CoV-2 IgG Antibodies Directed against Different Antigens.

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.

Analytical and clinical validation of an ELISA for specific SARS-CoV-2 IgG, IgA, and IgM antibodies.

The development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests is massive. The external validation of their performance is needed before use in clinical routine practice. Our study aims at assessing the analytical and clinical performance of two enzyme-linked immunosorbent assay tests detecting antibodies directed against the virus nucleocapsid protein: The NovaLisa SARS-CoV-2 immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM) test (NovaTec) allowing a separate detection of each antibody and the Platelia SARS-CoV-2 Total Ab test (Bio-Rad) detecting total antibodies (IgM, IgA, and IgG).

Implementation of rapid SARS-CoV-2 antigenic testing in a laboratory without access to molecular methods: Experiences of a general hospital.

Background: The COVID-19 Ag (Antigen) Respi-Strip assay is a new immunochromatographic diagnostic tool recently available for antigenic diagnosis of SARS-CoV-2. The proposed sensitivity is not higher than 60 %, but its high specificity allows both quick decisions for the management of patients and confirmation by molecular diagnosis for only negative tests. However, from the first tests performed, we suspected that the sensitivity observed with routine use was much lower than that announced by the manufacturer.