Third doses and comparable stats

Is the programme for third doses in older care homes ‘behind’?

Anthony B. Masters
2 min readDec 16, 2021


Each week, NHS England publishes updated Covid-19 vaccination statistics Up to 28th November, those weekly figures found:

  • Among residents in older adult care homes, 73% had a third vaccine dose.
  • In the population aged 65 and over, third dose coverage was 81%.
There is a focus on third doses in the vaccination programme. (Image: BBC)

The question arises: is the booster programme in care homes behind the population?

It is challenging to make a direct comparison between these two figures. First, residents in these homes have “small numbers” of younger residents, aged under 65.

Second, the age distribution in care homes differs to that the general population.

Third, the Office for National Statistics 2020 population figures are estimates. These estimates are subject to uncertainty. Recorded vaccinations with two doses of those aged 75 to 79 exceeds the ONS estimate. This is likely to be an underestimate of the living population. In turn, that gives a small overestimate of vaccine coverage. As a sensitivity analysis, growing the older population by 1% decreases coverage by 0.8 points.

Fourth, there is under-reporting of third doses in older adult care homes. In that weekly report, there were 256 homes reporting second — but not third — doses. The Department of Health and Social Care collects through its Capacity Tracker tool. The Department tolerates under-reporting in publication of these figures.

Another comparison would be the number of third doses, as a percentage of second doses. For the population aged 65 and over, that retention ratio is 84%.

Without adjusting for under-reporting, that is 76% for older adult care home residents. If the missing 256 care homes have the same size and vaccine coverage as those reporting, the estimate is ~78%.

There is a difference between older people in care homes and the wider population. Whilst there are some comparability issues between the statistics, the conclusion appears stable.



Anthony B. Masters

This blog looks at the use of statistics in Britain and beyond. It is written by RSS Statistical Ambassador and Chartered Statistician @anthonybmasters.