Antibodies against SARS-CoV-2 after natural infection in healthcare workers and clinical characteristics as putative antibody production prediction

D.A.T. Hanssen, J. Penders, K. Heijgele, S. de Leede, M. Mulder, L.E.A. Bank, M.H.C. Slaats, P.H.M. Savelkoul, I.H.M. van Loo*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Introduction: There is a need for detailed data on early antibody responses against SARS-CoV-2 as this may contribute to the prediction of the clinical course of COVID-19 and the optimization of convalescent plasma treatment. This study aims to gain insight into developing antibodies to SARS-CoV-2 in health care workers (HCWs) infected in the first wave of the SARS-CoV-2 pandemic in the Netherlands.Materials and methods: In this retrospective analysis, sera from PCR-confirmed COVID-19 positive HCWs are included at the time of the initial PCR (T = 0, n = 95) and at least 21 days after the initial serum (T >= 21, n = 133). This study assesses correlations between qualitative total Ig, IgM, IgA, IgG, and quantitative anti-S-RBD antibody responses and participant characteristics.Results: Higher Ct values were associated with higher antibody positivity rates for total Ig (OR 1.261 (95% CI 1.095-1.452)), IgM (OR 1.373 (95% CI 1.125-1.675)), and IgA (OR 1.222 (95% CI 1.013-1.475)). Gender was predictive of IgM and IgA antibody positivity rates at T = 0 (OR 0.018 (95% CI 0.001-0.268)) and (OR 0.070 (95% CI 0.008-0.646)). At T >= 21, a substantial proportion of HCWs developed IgM (103/133; 77.4%) and total Ig (128/133; 96.2%) antibodies. IgA and IgG seroconversions were observed in only 51.1% (67/131) and 55.7% (73/131) of HCWs. Anti-S-RBD responses were higher when the interval between onset of symptoms and sampling was longer.Conclusion: The findings of this study give insight into early antibody responses and may have implications for the selection of convalescent plasma donors and the further development of monoclonal antibody treatment.
Original languageEnglish
Article number100089
Number of pages5
JournalJournal of Clinical Virology Plus
Issue number3
Publication statusPublished - 1 Aug 2022


  • SARS-CoV-2
  • Serology
  • Antibodyresponse

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