Estimation of SARS-CoV-2 Infection Fatality Rate by Age and Comorbidity Status Using Antibody Screening of Blood Donors during the COVID-19 Epidemic in Denmark

Research output: Contribution to journalJournal articleResearchpeer-review

  • Kathrine Agergård Kaspersen
  • Lotte Hindhede
  • Jens Kjærgaard Boldsen
  • Susan Mikkelsen
  • Lasse Skafte Vestergaard
  • Ann Sofie Nicole Berthelsen
  • Ida Rask Moustsen-Helms
  • Dorte Kinggaard Holm
  • Anna Christine Nilsson
  • Susanne Gjørup Sækmose
  • Erik Sørensen
  • Bitten Aagaard
  • Søren Thue Lillevang
  • Charlotte Sværke Jørgensen
  • Tyra Grove Krause
  • Henrik Ullum
  • Christian Erikstrup

Background: Studies presenting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection fatality rate (IFR) for healthy individuals are warranted. We estimate IFR by age and comorbidity status using data from a large serosurvey among Danish blood donors and nationwide data on coronavirus disease 2019 (COVID-19) mortality. Methods: Danish blood donors aged 17-69 years donating blood October 2020-February 2021 were tested with a commercial SARS-CoV-2 total antibody assay. IFR was estimated for weeks 11 to 42, 2020 and week 43, 2020 to week 6, 2021, representing the first 2 waves of COVID-19 epidemic in Denmark. Results: In total, 84944 blood donors were tested for antibodies. The seroprevalence was 2% in October 2020 and 7% in February 2021. Among 3898039 Danish residents aged 17-69 years, 249 deaths were recorded. The IFR was low for people <51 years without comorbidity during the 2 waves (combined IFR=3.36 per 100000 infections). The IFR was below 3‰ for people aged 61-69 years without comorbidity. IFR increased with age and comorbidity but declined from the first to second wave. Conclusions: In this nationwide study, the IFR was very low among people <51 years without comorbidity.

Original languageEnglish
JournalJournal of Infectious Diseases
Issue number2
Pages (from-to)219-228
Number of pages10
Publication statusPublished - 2022

Bibliographical note

Publisher Copyright:
© 2021 The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail:

    Research areas

  • blood donors, infection fatality rate, SARS-CoV-2, seroprevalence

ID: 321550546