npj Vaccines (Dec 2022)

Titers of antibodies against ancestral SARS-CoV-2 correlate with levels of neutralizing antibodies to multiple variants

  • Trung The Tran,
  • Eline Benno Vaage,
  • Adi Mehta,
  • Adity Chopra,
  • Lisa Tietze,
  • Anette Kolderup,
  • Aina Anthi,
  • Marton König,
  • Gro Nygaard,
  • Andreas Lind,
  • Fredrik Müller,
  • Lise Sofie Nissen-Meyer,
  • Per Magnus,
  • Lill Trogstad,
  • Siri Mjaaland,
  • Arne Søraas,
  • Karsten Midtvedt,
  • Anders Åsberg,
  • Andreas Barratt-Due,
  • Asle W. Medhus,
  • Marte Lie Høivk,
  • Knut Lundin,
  • Randi Fuglaas Karlsen,
  • Reidun Dahle,
  • Karin Danielsson,
  • Kristine Stien Thomassen,
  • Grete Birkeland Kro,
  • Rebecca J. Cox,
  • Fan Zhou,
  • Nina Langeland,
  • Pål Aukrust,
  • Espen Melum,
  • Tone Lise Åvitsland,
  • Kristine Wiencke,
  • Jan Cato Holter,
  • Ludvig A. Munthe,
  • Gunnveig Grødeland,
  • Jan-Terje Andersen,
  • John Torgils Vaage,
  • Fridtjof Lund-Johansen

DOI
https://doi.org/10.1038/s41541-022-00586-7
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 11

Abstract

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Abstract Diagnostic assays currently used to monitor the efficacy of COVID-19 vaccines measure levels of antibodies to the receptor-binding domain of ancestral SARS-CoV-2 (RBDwt). However, the predictive value for protection against new variants of concern (VOCs) has not been firmly established. Here, we used bead-based arrays and flow cytometry to measure binding of antibodies to spike proteins and receptor-binding domains (RBDs) from VOCs in 12,000 serum samples. Effects of sera on RBD-ACE2 interactions were measured as a proxy for neutralizing antibodies. The samples were obtained from healthy individuals or patients on immunosuppressive therapy who had received two to four doses of COVID-19 vaccines and from COVID-19 convalescents. The results show that anti-RBDwt titers correlate with the levels of binding- and neutralizing antibodies against the Alpha, Beta, Gamma, Delta, Epsilon and Omicron variants. The benefit of multiplexed analysis lies in the ability to measure a wide range of anti-RBD titers using a single dilution of serum for each assay. The reactivity patterns also yield an internal reference for neutralizing activity and binding antibody units per milliliter (BAU/ml). Results obtained with sera from vaccinated healthy individuals and patients confirmed and extended results from previous studies on time-dependent waning of antibody levels and effects of immunosuppressive agents. We conclude that anti-RBDwt titers correlate with levels of neutralizing antibodies against VOCs and propose that our method may be implemented to enhance the precision and throughput of immunomonitoring.