Estimates of protection levels against SARS-CoV-2 infection and severe COVID-19 in Germany before the 2022/2023 winter season: the IMMUNEBRIDGE project


  • B. Lange
  • V.K. Jaeger
  • M. Harries
  • V. Rücker
  • H. Streeck
  • S. Blaschke
  • A. Petersmann
  • N. Toepfner
  • M. Nauck
  • M.J. Hassenstein
  • M. Dreier
  • I. von Holt
  • A. Budde
  • A. Bartz
  • J. Ortmann
  • M.A. Kurosinski
  • R. Berner
  • M. Borsche
  • G. Brandhorst
  • M. Brinkmann
  • K. Budde
  • M. Deckena
  • G. Engels
  • M. Fenzlaff
  • C. Härtel
  • O. Hovardovska
  • A. Katalinic
  • K. Kehl
  • M. Kohls
  • S. Krüger
  • W. Lieb
  • K.M. Meyer-Schlinkmann
  • T. Pischon
  • D. Rosenkranz
  • N. Rübsamen
  • J. Rupp
  • C. Schäfer
  • M. Schattschneider
  • A. Schlegtendal
  • S. Schlinkert
  • L. Schmidbauer
  • K. Schulze-Wundling
  • S. Störk
  • C. Tiemann
  • H. Völzke
  • T. Winter
  • C. Klein
  • J. Liese
  • F. Brinkmann
  • P.F. Ottensmeyer
  • J.P. Reese
  • P. Heuschmann
  • A. Karch


  • Infection


  • Infection 52 (1): 139-153


  • PURPOSE: Despite the need to generate valid and reliable estimates of protection levels against SARS-CoV-2 infection and severe course of COVID-19 for the German population in summer 2022, there was a lack of systematically collected population-based data allowing for the assessment of the protection level in real time. METHODS: In the IMMUNEBRIDGE project, we harmonised data and biosamples for nine population-/hospital-based studies (total number of participants n = 33,637) to provide estimates for protection levels against SARS-CoV-2 infection and severe COVID-19 between June and November 2022. Based on evidence synthesis, we formed a combined endpoint of protection levels based on the number of self-reported infections/vaccinations in combination with nucleocapsid/spike antibody responses ("confirmed exposures"). Four confirmed exposures represented the highest protection level, and no exposure represented the lowest. RESULTS: Most participants were seropositive against the spike antigen; 37% of the participants ≥ 79 years had less than four confirmed exposures (highest level of protection) and 5% less than three. In the subgroup of participants with comorbidities, 46-56% had less than four confirmed exposures. We found major heterogeneity across federal states, with 4-28% of participants having less than three confirmed exposures. CONCLUSION: Using serological analyses, literature synthesis and infection dynamics during the survey period, we observed moderate to high levels of protection against severe COVID-19, whereas the protection against SARS-CoV-2 infection was low across all age groups. We found relevant protection gaps in the oldest age group and amongst individuals with comorbidities, indicating a need for additional protective measures in these groups.