England antibody test estimates 3.4m people may have had Covid-19

13 Aug 2020

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A sample study involving 100,000 people in England found 6pc had antibodies to the coronavirus.

A research project led by Imperial College London looking to estimate how many people in England may have had Covid-19 has published its first results in a non-peer-reviewed study. The type of antibody test used in this study was deemed not accurate enough for widespread national testing, but suitable for surveillance studies.

More than 100,000 people across England tested themselves for SARS-CoV-2 antibodies at home using finger-prick tests, revealing that 6pc had antibodies to the virus and so had likely contracted Covid-19 some time before the end of June. Using the sample study as a representation for the entire population of England, this would suggest that around 3.4m people may have had Covid-19.

London had more than twice the national average of people who tested positive for antibodies, while the south-west had the lowest. Workers in care homes and healthcare workers represented the highest numbers of positive results.

Age also produced noticeable trends, with those aged between 18 and 24 showing the highest rates of antibodies (8pc), making them more than twice as likely to test positive compared to adults aged between 65 and 74 (3pc).

‘Still many unknowns with this new virus’

Black, Asian and minority ethnic individuals were between two and three times as likely to have had Covid-19 compared to white people, researchers said. Economics were also a factor, with the researchers stating that people from the poorest areas were more likely to have Covid-19 (7pc) compared to those from the least deprived areas (5pc).

“There are still many unknowns with this new virus, including the extent to which the presence of antibodies offers protection against future infections,” said Prof Graham Cooke, who led the research.

“Using the finger-prick tests suitable for large-scale home testing has given us clearest insight yet into the spread of the virus in the country and who has been at greatest risk. These data will have important implications for decisions around ongoing control measures in England.”

The findings coincide with reports that a new contact-tracing app will be trialled in England from today (13 August). A previous app that performed poorly in testing was replaced in June with one developed using the Google Apple Exposure Notification API that the Irish contact-tracing app is built on.

Northern Ireland already has its own contact-tracing app launched to the public, while Scotland is set to release an app in the coming months.

Colm Gorey was a senior journalist with Silicon Republic