Around eight in 10 adults in most parts of the UK now have Covid-19 antibodies, according to new estimates from the Office for National Statistics (ONS).
In England, sample blood test results for the week beginning 17 May suggest that 80.3 per cent of the adult population have coronavirus antibodies, either from a vaccine or having had the infection in the past.
The ONS said a clear correlation between vaccination and testing positive for antibodies emerges from the data: a month earlier they were detected in seven in 10, or 69.9 per cent of adults in England.
In the rest of the UK, the figure for Wales stands at 82.7 per cent in the same week, up from 66.8 per cent; Scotland’s estimate is 72.6 per cent, which is up from 59.9 per cent; and in Northern Ireland it is 79.9 per cent, which is up from 68.8 per cent.
It takes between two and three weeks after infection or vaccination for the body to make enough antibodies to fight the virus, but experts warn it’s difficult to measure herd immunity in the population.
The new figures come as Neil Ferguson, a leading epidemiologist at Imperial College London, told reporters on Wednesday that the new Delta ‘variant of concern’ is around 60% more transmissable than the Alpha variant that was previously dominant in the UK.
The authors of the ONS report stress that detection of antibodies alone is not a precise measure of the immunity protection given by vaccination.