Monthly age-standardised mortality rates (ASMRs) for deaths involving coronavirus (COVID-19) have been consistently lower for all months since September 2021 for people who had received a third dose or booster at least 21 days ago, compared with unvaccinated people and those with just a first or second dose.

Breaking the ASMRs down by age group, those aged over 50 years who had received a booster at least 21 days ago had lower ASMRs in all months, compared with unvaccinated people; this has also been the case among younger age groups where rates can be calculated, although trends are now less clear because of lower mortality rates with large confidence intervals.

Before March 2022, those who had received a second dose over six months ago had higher monthly ASMRs for deaths involving COVID-19 than those who had received a second dose less than six months ago; this indicates a possible waning protection from vaccination over time.

The age-adjusted rates are not equivalent to measures of vaccine effectiveness; they account for differences in age structure and population size, but there may be other differences between the groups (particularly underlying health) that affect mortality rates.

Changes in non-COVID-19 mortality by vaccination status are largely driven by the changing composition of the vaccination status groups; this is because of the prioritisation of people who are clinically extremely vulnerable or have underlying health conditions, and differences in timing of vaccination among eligible people.

Non-COVID-19 mortality rates can also be affected by seasonal mortality and the healthy vaccinee effect.