Previous SARS-CoV-2 infections and their impact on the protection from reinfection during the Omicron BA.5 wave – a nested case-control study among vaccinated adults in Sweden
Objectives: We evaluated the protection afforded by SARS-CoV-2 infection-induced immunity against reinfection among working-age vaccinated individuals during a calendar period from June to December 2022 when Omicron BA.5 was the dominating subvariant in Scania County, Sweden. Methods: The study cohort (n = 71,592) mainly consisted of health care workers. We analyzed 4144 infected cases during the