Data on government’s antibody testing strategy cannot yet be trusted

Large scale antibody testing is risking inefficient use of scarce resources, according to a group of senior clinical academics and physicians who are concerned about the rapid roll out of Covid-19 antibody testing in England.In a letter to The BMJ, they argue that there is currently no valid clinical reason for large scale testing as test performance has not yet been adequately assessed.

As a positive antibody test result €œdoes not indicate immunity€ and that the concept of €˜immune passports’ that allow people to work, has not been established, the experts say that routine testing of patients is neither clinically urgent nor meets a clear public health need.

Concerns were also raised that the tests are being rolled out at an unprecedented pace and scale without adequate assessment, and with no data on performance in people at high risk including the elderly and those in black and minority ethnic groups.

We don’t have much data and we can’t trust any of it

UK Prime Minister Boris Johnson has described antibody testing as €œgame-changing€ and last month the government purchased 10 million test kits from Abbott and Roche after Public Health England (PHE) studies showed they worked. However, the head of the NHS test-and-trace programme, Baroness Dido Harding, has said not enough was known about what level of protection coronavirus antibodies provided.

Professor Jon Deeks at the University of Birmingham, who has led the first systematic review of studies on covid-19 antibody tests, said: €œWe don’t have much data and we can’t trust any of it.€

Monitoring the covid-19 epidemic is important, they write, but the only current justification for large scale covid-19 antibody testing is for research purposes, including public health surveillance to inform epidemiology. 

€œWe would like to see a carefully developed and clearly articulated strategy for serological testing, with clear scientific or clinical aims (or both) as part of a unified covid-19 response strategy,€ they conclude.

In another investigation, Sheila Bird from Edinburgh University’s College of Medicine and Veterinary Medicine said that there were several problems with PHE’s evaluation of the Roche and Abbott tests, including quality of samples, the absence of data on age and sex, and use of repeat samples.

Others experts have argued that the purpose of the tests are still unclear, and that the demand for an expensive fast turnaround is arguably a waste of public money.