New figures from the Office for National Statistics (ONS) show the percentage of the UK population estimated to have COVID-19 antibodies is declining rapidly, prompting calls for the government to start its autumn booster vaccination campaigns as soon as possible.
The latest ONS data revealed the estimated percentage of the population in England with an antibody level of at least 800ng/ml dropped from a peak of 82.4% in March 2022 to 71.9% by mid-July, a decline of 12.7%.
The data was similar throughout the UK, with high antibody levels also declining in Scotland, Wales and Northern Ireland.
Dr Quinton Fivelman, chief scientific officer at private testing company London Medical Laboratory, said: “This dramatic 12.7% decrease in the number of people in England with a significant number of antibodies to COVID-19 is obviously concerning.
“We already know the latest Omicron BA.4 and BA.5 sub-variants are the most contagious yet and remain a potentially considerable threat to our health. The UK population needs to retain a substantial number of antibodies going into the dangerous winter months.”
Despite the decline, the UK has retained a baseline antibody level of at least 179ng/ml, determined at the height of the Delta variant. In mid-March, 97.8% of people in England had antibody levels of 179ng/ml, and this had fallen only fractionally to 96.3% by mid-July.
Fivelman emphasised that, if the rate of decline continues, only 60% of the UK population will retain substantial antibodies by the time they receive their booster. He also pointed out that the new Omicron BA.4 and BA.5 sub-variants do not produce as high an immune response as the previous strains, so re-infection is more likely to occur.
Currently, the UK’s autumn booster campaign includes everyone aged 50 and over, high-risk people aged five to 49 years old, care home staff, frontline health and social care workers, unpaid carers and household contacts of people with weakened immune systems.
Originally the autumn booster campaign was due to include all those over the age of 65, rather than all those over the age of 50, but the programme has been expanded in response to the spread of the Omicron variant.