Persistence of immunity to SARS-CoV-2 over time in the ski resort Ischgl
Wegene Borena,
Zoltán Bánki,
Katie Bates,
Hannes Winner,
Lydia Riepler,
Annika Rössler,
Lisa Pipperger,
Igor Theurl,
Barbara Falkensammer,
Hanno Ulmer,
Andreas Walser,
Daniel Pichler,
Matthias Baumgartner,
Sebastian Schönherr,
Lukas Forer,
Ludwig Knabl,
Reinhard Würzner,
Dorothee von Laer,
Jörg Paetzold,
Janine Kimpel
Affiliations
Wegene Borena
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria
Zoltán Bánki
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria
Katie Bates
Department of Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck, Austria
Hannes Winner
University of Salzburg, Department of Economics, Residenzplatz 9, Salzburg A-5010, Austria
Lydia Riepler
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria
Annika Rössler
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria
Lisa Pipperger
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria
Igor Theurl
Labor Dr. Theurl, Franz-Fischerstr.7b, Innsbruck, Austria
Barbara Falkensammer
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria
Hanno Ulmer
Department of Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck, Austria
Andreas Walser
Walser's surgery, Ischgl, Austria
Daniel Pichler
Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Innsbruck 6020, Austria
Matthias Baumgartner
Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Innsbruck 6020, Austria
Sebastian Schönherr
Institute of Genetic Epidemiology, Medical University of Innsbruck, Austria
Lukas Forer
Institute of Genetic Epidemiology, Medical University of Innsbruck, Austria
Ludwig Knabl
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria
Reinhard Würzner
Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Innsbruck 6020, Austria
Dorothee von Laer
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria
Jörg Paetzold
University of Salzburg, Department of Economics, Residenzplatz 9, Salzburg A-5010, Austria; Corresponding authors.
Janine Kimpel
Institute of Virology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Peter-Mayr-Str. 4b, Innsbruck 6020, Austria; Corresponding authors.
Background In early March 2020, a SARS-CoV-2 outbreak in the ski resort Ischgl in Austria triggered the spread of SARS-CoV-2 throughout Austria and Northern Europe. In a previous study, we found that the seroprevalence in the adult population of Ischgl had reached 45% by the end of April, representing an exceptionally high level of local seropositivity in Europe. We performed a follow-up study in Ischgl, which is the first to show persistence of immunity and protection against SARS-CoV-2 and some of its variants at a community level.Methods Of the 1259 adults that participated in the baseline study, 801 have been included in the follow-up in November 2020. The study involved the analysis of binding and neutralizing antibodies and T cell responses. In addition, the incidence of SARS-CoV-2 and its variants in Ischgl was compared to the incidence in similar municipalities in Tyrol until April 2021.Findings For the 801 individuals that participated in both studies, the seroprevalence declined from 51.4% (95% confidence interval (CI) 47.9–54.9) to 45.4% (95% CI 42.0–49.0). Median antibody concentrations dropped considerably (5.345, 95% CI 4.833 – 6.123 to 2.298, 95% CI 2.141 – 2.527) but antibody avidity increased (17.02, 95% CI 16.49 – 17.94 to 42.46, 95% CI 41.06 – 46.26). Only one person had lost detectable antibodies and T cell responses. In parallel to this persistent immunity, we observed that Ischgl was relatively spared, compared to similar municipalities, from the prominent second COVID-19 wave that hit Austria in November 2020. In addition, we used sequencing data to show that the local immunity acquired from wild-type infections also helped to curb infections from variants of SARS-CoV-2 which spread in Austria since January 2021.Interpretation The relatively high level of seroprevalence (40–45%) in Ischgl persisted and might have been associated with the observed protection of Ischgl residents against virus infection during the second COVID-19 wave as well as against variant spread in 2021.Funding Funding was provided by the government of Tyrol and the FWF Austrian Science Fund.
