SIX per cent of the population in England may have antibodies for coronavirus, according to research published by Imperial College London.
This equates to around 3.4 million people having been infected with COVID-19.
The research involved over 100,000 volunteers in England undertaking antibody finger prick tests at home between 20 June and 13 July to check for antibodies against the virus which causes COVID-19.
The study found some significant variations among populations, with 13 per cent of Londoners testing positive for antibodies compared to three per cent in the South West of England. People living in the most deprived areas had higher antibody levels than those in the wealthiest areas (seven per cent compared with five per cent) and those in households of more than seven people were more likely to have had the virus (13 per cent) compared to those living alone or with one other (five per cent).
Rates were higher among Black (17 per cent) and Asian (12 per cent) ethnicities compared to five per cent of whites. The study also showed high rates in people working in care homes (16 per cent) and healthcare (12 per cent), compared to five per cent of people who were not key workers.
Individuals aged 18 to 34 were most likely to have antibodies (eight per cent) with the lowest prevalence in those over 65 (three per cent).
Almost everyone with a confirmed case of COVID was found to have antibodies (96 per cent).
Two further papers assessing home antibody self-testing have also been published and underpin the Imperial College findings. The first, published in the journal Thorax analysed 11 finger prick antibody tests to evaluate accuracy and ease of use among NHS workers. Four of the best performing self-tests were able to accurately identify individuals with antibodies over 80 per cent of the time, while also correctly ruling out those without antibodies in more than 98 per cent of tested individuals. A second study, published in Clinical Infectious Diseases found that among over 14,000 members of the general public, 97 per cent were able to successfully perform the test on their own with 94 per cent obtaining a valid result.
No antibody finger pick test currently meets MHRA criteria for individual use outside of surveillance studies.
Professor Helen Ward, lead author for the study of population prevalence, commented: "Thanks to the contribution of tens of thousands of members of the public, we have shown that the pandemic of SARS-CoV-2 infection in England has spread very unevenly. It has fallen particularly heavily on ethnic minority groups and key workers, particularly in care homes and healthcare. Those in deprived and densely populated areas are most likely to have been exposed to the virus, and we need to do far more to protect people from any future waves of infection."
Health Minister Edward Argar said: "Large scale antibody surveillance studies are crucial to helping us understand how the virus has spread across the country and whether there are specific groups who are more vulnerable, as we continue our work to drive down the spread of the disease.
"We don’t yet know that antibodies provide immunity to coronavirus, but the more information we can gather on this virus, and the easier we can make it for people to participate in these studies, the better equipped we will be to respond."