Public Health England will not change point-of-care COVID-19 antibody testing advice, despite SAGE evidence

Advice against using rapid point-of-care COVID-19 antibody tests in community pharmacies will not be changing, despite a report from experts claiming that the tests are “performing well”, Public Health England (PHE) has confirmed.

The report on COVID-19 antibody testing, published on 17 July 2020, was presented to the government’s Scientific Advisory Group for Emergencies (SAGE) at its meeting on 2 July 2020.

Wendy Barclay, head of the department of infectious diseases, and Peter Openshaw, professor of experimental medicine — both at Imperial College London — said in the report that “some of the commercial [rapid point-of-care (POC) antibody] tests that have come to market more recently are performing well”.

They said this is despite early reports suggesting “poor performance that would preclude utility”.

Rapid POC tests — or lateral flow immunoassays (LFIA) — use finger-prick blood to detect COVID-19 antibodies.

The report says that 14 LFIAs have been assessed by the government’s antibody testing study.

However, PHE told The Pharmaceutical Journal on 20 July 2020 that its current advice against their use at home or in community pharmacies still stands, as the SAGE report also describes the potential for false positive and false negative results, and highlights the continued areas of uncertainty around the presence of antibodies and immunity.

The report says that, even with the best rapid POC antibody test, “there will be a substantial number of people whose test results will be called wrongly”.

“If seroprevalence is 10%, a test with 97.8% sensitivity and the same specificity calls incorrectly 2 people in every 1,000 as not having been infected when they had been — and 20 people in every 1,000 as being potentially ‘immune’ when they have not been infected,” it continued.

The existing PHE advice, issued on 11 May 2020, notes that some manufacturers are selling testing kits “that allow a swab or other type of sample to be taken at home or in the pharmacy setting”, some of which “look for the body’s immune response to the virus”.

“The current view by PHE is that use of products that give a very rapid result is not advised,” it says, adding that there is little information on their accuracy and “on how a patient’s antibody response develops or changes during COVID-19 infection”.

The Pharmaceutical Journal revealed on 15 July 2020 that 470 community pharmacies in the UK are already offering a rapid finger-prick COVID-19 antibody testing service.

Rapid POC antibody tests are legally allowed to be sold to members of the public, provided they are CE-marked, but pharmacies are advised against doing so by both PHE and the General Pharmaceutical Council.

However, reports have suggested that government ministers are drawing up plans to distribute millions of rapid POC tests — developed by the UK Rapid Test Consortium — to members of the public for use at home.

Commenting on these plans, the Department of Health and Social Care (DHSC) said no antibody tests have been approved for at-home use.

“We have received an extraordinary response to our call to action to supply antibody tests, and we continue to work with industry to identify further tests that are safe and accurate to be used at home,” a spokesperson said.

“While these tests will help us better understand how COVID-19 is spreading across the country, we do not yet know whether antibodies indicate immunity from reinfection or transmission.”

The DHSC, PHE and Medicines and Healthcare products Regulatory Agency began recruiting 2,500 volunteers from the NHS and wider public services in June 2020 to evaluate finger-prick COVID-19 antibody tests that can be taken at home. The results are expected in the late summer.