Initial characterisation of commercially available ELISA tests and the immune response of the clinically correlated SARS-CoV-2 biobank “SERO-BL-COVID-19” collected during the pandemic onset in Switzerland

Abstract

<jats:p>Background: To accurately measure seroprevalance in the population, boththe expected immune response as well as the assay performances have to be well characterised. Here, we describe the collection and initial characterisation of a blood and saliva biobank obtained after the initial peak of the SARS-CoV-2 pandemic in Switzerland. Methods: Two laboratory ELISA assays measuring IgA &amp; IgG (Euroimmun), and IgM &amp; IgG (Epitope Diagnostics) were used to characterise the biobank collected from 349 re- and convalescent patients from the canton of Basel-Landschaft. Findings: The antibody response in terms of recognized epitopes is diverse, especially in oligosymptomatic patients, while the average strength of the antibody response of the population does correlate with the severity of the disease at each time point. Interpretation: The diverse immune response presents a challenge when conducting epidemiological studies as the used assays only detect 90% of the oligosymptomatic cases. This problem cannot be rectified by using more sensitive assays or lower cut-offs as they concomitantly reduce specificity. Funding Funding was obtained from the Amt fur Gesundheit of the canton Basel-Landschaft, Switzerland.</jats:p>

A single-cell atlas of lymphocyte adaptive immune repertoires and transcriptomes reveals age-related differences in convalescent COVID-19 patients

“…We performed scSeq of immune receptor repertoires and transcriptomes of lymphocytes from convalescent COVID-19 patients to characterize the adaptive immune response against SARS-CoV-2. For this purpose, we selected eight patients enrolled in the SERO-BL-COVID-19 clinical study 39 , all of which fully recovered from COVID-19 without requiring hospitalization or the administration of Supplementary oxygen. Patients tested positive for the presence of SARS-CoV-2 after RT-PCR of naso/oropharyngeal swab samples (day 0), displayed COVID-19 symptoms for 4-14 days, and showed positive seroconversion at the time of blood collection (mean sample collection time = 32.5 ± 4.1 days post-symptom onset) ( Fig.…”

Clinical Characterisation of Eleven Lateral Flow Assays for Detection of COVID-19 Antibodies in a Population

“…Lot numbers and expiration dates are given in (Supp. We assayed the Hightop test using whole blood, 24 serum and plasma , while all other tests were assayed using serum and plasma. The Hightop and MEDSan assays were characterised at the SwissTPH using the identical biobank and experimental setup as outlined previously.…”

Single-cell sequencing of plasma cells from COVID-19 patients reveals highly expanded clonal lineages produce specific and neutralizing antibodies to SARS-CoV-2

“…Peripheral blood samples were isolated from a set of 16 convalescent COVID-19 patients, which was part of a larger cohort biobank (SERO-BL-COVID-19) (30) . Among the selected group of 16, all patients were confirmed to be SARS-CoV-2-positive by RT-PCR testing; point-of-care lateral flow tests (POCT) confirmed serum IgM and IgG antibody responses to SARS-CoV-2 S1 and nucleocapsid protein (NCP) antigens ( Fig.…”

“…Zentralschweiz (EKNZ)". Every participant has signed a written informed consent as described previously (30).…”

“…Patients included in the subset were selected based on POCTs assessing the presence of IgG and IgM SARS-CoV-2-specific antibodies (Qingdao Hightop Biotech, #H100), performed at the time of blood collection, after resolution of symptoms as seen from Fig.1. PMBCs were isolated as described previously (30). In brief, PBMCs were isolated from EDTA blood using density gradient separation in Ficoll Paque Plus reagent (GE Healthcare, #17-1440-02).…”