Across the world, more than 2bn doses of Covid-19 vaccines have gone into arms, and on 2 June, the BBC headline “75% of UK adults have had [their] first vaccine jab” was based on an Office for National Statistics estimate of the UK population aged 18 or over in June 2019.
Underneath this encouraging headline statistic, things get a bit more complicated. Consider those aged between 75 and 79. NHS England reports 1,984,700 first vaccinations have been given to this age group, but this is over 40,000 more than the ONS population estimate of 1,940,686. So NHS England reports that more than 100% of people in this group have been vaccinated: Public Health Scotland also reports many age groups with 100% coverage.
So have some older people been able to fiddle more jabs? No. As people age, they move into older age groups and mortality rates improve. In June 2019, there were more people aged 73-74 than 78-79. Fast forward to June 2021 and the number in the 75-79 group has increased. Migration also affects these statistics.
Alternative counts come from the National Immunisation Management System (NIMS), which says 2,084,180 people aged 75-79 are registered with GPs, 140,000 more than the ONS population estimate, which leads to a claim of 95% coverage. But people may register in more than one place and so the true figure will probably be more than 95%.
You may be surprised that we don’t know how many people there are in the country, but that’s why we need better data on migration and a regular and efficient census. Fortunately, one has just come along, which covered an impressive 97% of households. The OpenSAFELY analysis of 23m electronic patient records estimates that among 70-79s up to 26 May, 97% of people of white ethnicity had been vaccinated at least once, compared with 73% of black ethnicity. This means nine times the proportion of unvaccinated people in the black population compared with those who are white.
In the current race between the Delta variant (originating in India) and the vaccine rollout, these disparities only add to the unequal impacts of this virus.