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

J Infect Dis. 2022 Jan 18;225(2):219-228. doi: 10.1093/infdis/jiab566.

Abstract

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.

Keywords: SARS-CoV-2; blood donors; infection fatality rate; seroprevalence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Viral / blood*
  • Blood Donors*
  • COVID-19 / blood
  • COVID-19 / diagnosis*
  • COVID-19 / epidemiology
  • Comorbidity
  • Denmark / epidemiology
  • Female
  • Humans
  • Male
  • Middle Aged
  • SARS-CoV-2 / isolation & purification*
  • Seroepidemiologic Studies
  • Young Adult

Substances

  • Antibodies, Viral