Scientific Reports (Jan 2023)

Diagnostic performance between in-house and commercial SARS-CoV-2 serological immunoassays including binding-specific antibody and surrogate virus neutralization test (sVNT)

  • Poramed Winichakoon,
  • Jiraprapa Wipasa,
  • Kriangkrai Chawansuntati,
  • Parichat Salee,
  • Tavitiya Sudjaritruk,
  • Saowaluck Yasri,
  • Chantana khamwan,
  • Rungnapa Peerakam,
  • Dararat Dankai,
  • Romanee Chaiwarith

DOI
https://doi.org/10.1038/s41598-022-26202-1
Journal volume & issue
Vol. 13, no. 1
pp. 1 – 9

Abstract

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Abstract This study aimed to evaluate the correlation between in-house and commercial binding-specific IgG antibodies and between in-house and commercial SARS-CoV-2 surrogate virus neutralization tests (sVNT). Samples from healthcare workers who received vaccines against SARS-CoV-2 were tested for RBD-specific antibody, S-specific antibody, and in-house ELISA, commercial sVNT, and in-house sVNT, against wild-type SARS-CoV-2. Three hundred and five samples were included in the analysis. The correlation between S-specific binding antibodies and in-house ELISA was 0.96 (95% CI 0.96–0.97) and between RBD-specific antibodies and in-house ELISA was 0.96 (95% CI 0.95–0.97). The Cohen’s kappa between in-house sVNT and the commercial test was 0.90 (95% CI 0.80, 1.00). If using 90% inhibition of sVNT as the reference standard, the optimal cut-off value of RBD-specific antibodies was 442.7 BAU/mL, the kappa, sensitivity, and specificity being 0.99, 99%, and 100%, respectively. The optimal cut-off value of S-specific antibodies was 1155.9 BAU/mL, the kappa, sensitivity, and specificity being 0.99, 100%, and 99%, respectively. This study demonstrated a very strong correlation between in-house ELISA and 2 commercial assays. There was also a very strong correlation between in-house and commercial SARS-CoV-2 sVNT, a finding of particular interest which will inform future research.