Comparative effectiveness of heterologous third dose vaccine schedules against severe covid-19 during omicron predominance in Nordic countries: population based cohort analyses
Objective To investigate the comparative vaccine effectiveness of heterologous booster schedules (ie, three vaccine doses) compared with primary schedules (two vaccine doses) and with homologous mRNA vaccine booster schedules (three vaccine doses) during a period of omicron predominance. Design Population based cohort analyses. Setting Denmark, Finland, Norway, and Sweden, 27 December 2020 to 31 December 2022. Participants All adults aged ≥18 years who had received at least a primary vaccination schedule of AZD1222 (Oxford-AstraZeneca) or monovalent SARS-CoV-2 wild type (ancestral) strain ba...
Source: bmj.com