Vaccine effectiveness against COVID-19-related death (vs unvaccinated)
For the ≥80-years, complete primary vaccination VE against COVID-19-related death varied between 41.4% (95%CI: 26.0; 53.6) in March–April 2022 and 45.1% (95%CI: -29.2; 76.6) in October–November 2022. The corresponding figures for the 65–79-years were 21.3% (95%CI: -19.8; 48.2) and 45.0% (95%CI: -28.0; 76.4) (Table S1, Figure 3).
We observed a decrease in the first booster VE estimates between March-April 2022 and October-November 2022 from 83.5% (95%CI: 73.2; 89.8) to 64.4% (95%CI: 51.8; 73.7) for the ≥80-years and from 85.4% (95%CI: 79.3; 89.8) to 43.1% (95%CI: 4.9; 66.0) for the 65–79-years (Table S2, Figure 2).
The second booster VE for ≥80-years remained above 80% between June-July 2022 and October-November 2022, showing no evident trends (Table S3, Figure 2). For the 65–79-years second booster VE was 77.0% (95%CI: 47.6; 89.9) in the last observation period (October-November 2022).