Cohort study of Covid-19 vaccine effectiveness among healthcare workers in Finland, December 2020 - October 2021
Eero Poukka, Ulrike Baum, Arto A. Palmu, Toni Lehtonen, Heini Salo, Hanna Nohynek, Tuija Leino
Abstract
Recently, Covid-19 vaccine effectiveness has decreased especially against mild disease due to emergence of the Delta variant and waning protection. In this register-based study among healthcare workers in Finland, the vaccine effectiveness of two-dose mRNA vaccine series against SARS-CoV-2 infection decreased from 82% (95% CI 79-85%) 14-90 days after vaccination to 53% (43-62%) after 6 months. Similar trend was observed for other series. Waning was not observed against Covid-19 hospitalization. These results facilitate decision-making of booster doses for healthcare workers.
Topics & Concepts
MedicineVaccinationBooster (rocketry)Coronavirus disease 2019 (COVID-19)Health careCohortBooster doseSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)PandemicCohort study2019-20 coronavirus outbreakVirologyDiseaseInternal medicineInfectious disease (medical specialty)VirusOutbreakAstronomyPhysicsEconomic growthTiterEconomicsSARS-CoV-2 and COVID-19 ResearchVaccine Coverage and HesitancyCOVID-19 Clinical Research Studies