I’m unsure, but does mean they are still detecting antibodies in those that had it back in spring / summer ?
These are from Oct/ Dec so if done now those with antibodies must be higher than these figures.
The proportion of the population testing positive for Covid-19 antibodies almost doubled between October and December 2020, according to Office for National Statistics estimates.
Approximately one in 10 people had antibodies against the virus across the UK in December, with England topping the list at one in eight people or about 12% of the population.
That equates to 5.4 million people over the age of 16.
In Wales, an estimated one in 10 had antibodies and one in 11 in Scotland. The likelihood of having antibodies was lowest in Northern Ireland at one in 13 or 7.6%.
Since October, the number of people with Covid antibodies has increased across the UK.
Yorkshire and the Humber has overtaken London as having the highest proportion of people with antibodies at 16.8%, up from 9.5% when the ONS last published the figures in October, and from below 5% in May.
London is close behind at 16.4%, up from 11% in October. At the last peak in May, 15% of the population in London had antibodies, but this fell, as detectable antibodies recede with time.
In the North West, 15% of people had antibodies, more than doubling from 6% in October.