Six-month antibody response to SARS-CoV-2 in healthcare workers assessed by virus neutralization and commercial assays.
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ABSTRACT:
SUBMITTER: Bal A
PROVIDER: S-EPMC7803622 | biostudies-literature | 2021 Jun
REPOSITORIES: biostudies-literature
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Six-month antibody response to SARS-CoV-2 in healthcare workers assessed by virus neutralization and commercial assays.
Bal Antonin A Trabaud Mary-Anne MA Fassier Jean-Baptiste JB Rabilloud Muriel M Saker Kahina K Langlois-Jacques Carole C Guibert Nicolas N Paul Adèle A Alfaiate Dulce D Massardier-Pilonchery Amélie A Pitiot Virginie V Morfin-Sherpa Florence F Lina Bruno B Pozzetto Bruno B Trouillet-Assant Sophie S
Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases 20210113 6
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Project description:Background Commercially available ELISA-based antibody tests are used to approximate vaccination success against SARS-CoV-2 in at-risk patients, but it is unclear whether they correlate with neutralization of the Omicron variant. Methods 269 serum samples of a cohort of 44 non-immunosuppressed participants and 65 MTX-treated rheumatic patients taken before and after COVID-19 booster vaccinations were measured using COVID-19 antibody testing systems with wild-type and Omicron BA.1 antigens developed by three different manufacturers (surrogate virus neutralization test cPass, and binding antibody tests QuantiVac and SeraSpot), as well as with a pseudovirus neutralization test (pVNT). The pVNT was considered the gold standard for determining the presence and level of anti-SARS-CoV-2 antibodies. Results All three wild type ELISAs showed excellent test performance compared with wild type neutralization in pVNT. However, out of 56 samples without Omicron BA.1 neutralization in pVNT, 71.4% showed positive results in at least one and 28.6% in all three wild-type ELISAs at the manufacturer-defined cut-offs. Omicron ELISAs showed either decreased specificity (57.1% and 55.4% for binding ELISAs) or sensitivity (51.2% in cPass) compared to Omicron neutralization in pVNT. The proportion of any false positive results among all samples decreased from 26.5% before to 3.2% after booster vaccination, however binding antibody test specificities remained below 70%. Conclusions We found a poorer test performance of new Omicron antibody test systems compared to wild-type tests in detecting neutralizing antibodies against the corresponding SARS-CoV-2 variants. Decisions for booster vaccination or passive immunization of at-risk patients should not be based solely on antibody test results.
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Project description:BackgroundThe performance of the Roche Elecsys® Anti-SARS-CoV-2, Abbott Architect SARS-CoV-2 IgM, Abbott Architect SARS-CoV-2 IgG, Euroimmun SARS-CoV-2 IgA, Euroimmun SARS-CoV-2 IgG ELISA, and Trillium IgG/IgM rapid assays was evaluated in Jamaica.MethodsDiagnostic sensitivities of the assays were assessed by testing serum samples from SARS-CoV-2 PCR-confirmed persons and diagnostic specificity was assessed by testing serum samples collected during 2018-2019 from healthy persons and from persons with antibodies to a wide range of viral infections.ResultsSerum samples collected ≥14 days after onset of symptoms, or an initial SARS-CoV-2 RT-PCR positive test for asymptomatics, showed diagnostic sensitivities ranging from 67.9 to 75.0% when including all possible disease severities and increased to 90.0-95.0% when examining those with moderate to critical disease. Grouping moderate to critical disease showed a significant association with a SARS-CoV-2 antibody positive result for all assays. Diagnostic specificity ranged from 96.7 to 100.0%. For all assays examined, SARS-CoV-2 real-time PCR cycle threshold (Ct) values of the initial nasopharyngeal swab sample testing positive were significantly different for samples testing antibody positive versus negative.ConclusionsThese data from a predominantly African descent Caribbean population show comparable diagnostic sensitivities and specificities for all testing platforms assessed and limited utility of these tests for persons with asymptomatic and mild infections.
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