{"doi":"10.1111/eci.13520","title":"SARS‐CoV‐2 re‐infection risk in Austria","abstract":"<h4>Background</h4>A key question concerning coronavirus disease 2019 (COVID-19) is how effective and long lasting immunity against this disease is in individuals who were previously infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We aimed to evaluate the risk of SARS-CoV-2 re-infections in the general population in Austria.<h4>Methods</h4>This is a retrospective observational study using national SARS-CoV-2 infection data from the Austrian epidemiological reporting system. As the primary outcome, we aim to compare the odds of SARS-CoV-2 re-infections of COVID-19 survivors of the first wave (February to April 30, 2020) versus the odds of first infections in the remainder general population by tracking polymerase chain reaction (PCR)-confirmed infections of both groups during the second wave from September 1 to November 30, 2020. Re-infection counts are tentative, since it cannot be excluded that the positive PCR in the first and/or second wave might have been a false positive.<h4>Results</h4>We recorded 40 tentative re-infections in 14 840 COVID-19 survivors of the first wave (0.27%) and 253 581 infections in 8 885 640 individuals of the remaining general population (2.85%) translating into an odds ratio (95% confidence interval) of 0.09 (0.07 to 0.13).<h4>Conclusions</h4>We observed a relatively low re-infection rate of SARS-CoV-2 in Austria. Protection against SARS-CoV-2 after natural infection is comparable with the highest available estimates on vaccine efficacies. Further well-designed research on this issue is urgently needed for improving evidence-based decisions on public health measures and vaccination strategies.","journal":"European Journal of Clinical Investigation","year":2021,"id":8570,"datarank":0.7412463633913957,"base_score":4.941642422609304,"endowment":4.941642422609304,"self_citation_contribution":0.7412463633913957,"citation_network_contribution":0.0,"self_endowment_contribution":0.7412463633913957,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":139,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.1688,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-02-21","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":69425,"name":"Ali Chakeri","orcid":"0009-0005-7793-5271","position":1,"is_corresponding":false},{"id":148,"name":"John P. A. Ioannidis","orcid":"0000-0003-3118-6859","position":2,"is_corresponding":false},{"id":17138,"name":"Lukas Richter","orcid":"0000-0001-6982-6239","position":3,"is_corresponding":false},{"id":3317,"name":"Verena Theiler‐Schwetz","orcid":"0000-0002-2378-689X","position":4,"is_corresponding":false},{"id":3315,"name":"Christian Trummer","orcid":"0000-0001-5817-4554","position":5,"is_corresponding":false},{"id":3316,"name":"Robert Krause","orcid":"0000-0003-1558-0397","position":6,"is_corresponding":false},{"id":69426,"name":"Franz Allerberger","orcid":"0000-0002-0045-8164","position":7,"is_corresponding":false},{"id":3313,"name":"Stefan Pilz","orcid":"0000-0002-7959-1311","position":0,"is_corresponding":true}],"reference_count":28,"raw_metadata":null,"created_at":"2026-03-01T18:20:47.508186Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}