Waning protection after vaccination and prior infection against COVID-19-related mortality over 18 months
OBJECTIVES: Evidence on waning patterns in protection from vaccine-induced, infection-induced, and hybrid immunity against death is scarce. The aim of this study is to assess the temporal trends in protection against mortality.METHODS: Population-based case-control study nested in the total population of Scania Region, Sweden using individual-level registry data of COVID-19-related deaths (