A group of senior medical experts have raised concerns about coronavirus antibody tests being carried out on NHS and care staff.
The blood tests – described by Prime Minister Boris Johnson as potentially “game-changing” – can tell whether a person has had COVID-19 in the past.
The government purchased 10 million test kits from pharmaceutical giant Abbott and Roche last month, with the first phase of the testing programme assessing NHS and care workers.
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But in a letter published by the British Medical Journal, a group of academics and clinicians have voiced concerns about the performance of the tests and warned they risk “inefficient use of scarce resources”.
They said that a positive or negative test result would not alter the management of a patient and added that a positive result “does not indicate immunity”.
“The concept of ‘immune passports’, allowing healthcare workers or others to work, has not been established,” they wrote.
“Those with a positive antibody test should still consider themselves at risk and follow infection control policies…. There is, therefore, no benefit to healthcare organisations or to others in knowing the status of employees at present.”
The government purchased 10 million test kits from pharmaceutical firm Abbott and Roche
The experts say the tests are being rolled out “at an unprecedented pace and scale without adequate assessment”.
There is also currently no data showing the performance of tests in people at high risk including the elderly and those in black and minority ethnic groups, they add.
NHS England requires the results of antibody tests to be available within 24 hours.
But the academics warn: “Given that routine testing of patients is neither clinically urgent nor meets a clear public health need, this push to introduce a non-evidence based test for uncertain gains risks inefficient use of scarce resources.”
They concluded that the “only current justification” for large-scale COVID-19 antibody testing is “for research purposes”.
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The letter is signed by 14 medical experts including Dr Monique Andersson, consultant in infection at Oxford University Hospitals; Neil French, professor of infectious diseases and global health at the University of Liverpool; and Deenan Pillay, professor of virology at University College London.
Antibodies are produced by the immune system when it is being attacked in order to destroy substances which carry disease.
But how the immune system reacts to the COVID-19 virus remains uncertain.
The government website states that “while the results of an antibody test will not allow people to make any changes to their behaviour… there’s clear value in knowing whether NHS and care workers and hospital patients and care home residents have had the virus, and in collecting data on the test results”.
In a statement to The BMJ, the Department of Health and Social Care said: “We do not currently know how long an antibody response to the virus lasts, nor whether having antibodies means a person cannot transmit it to others.”
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But the spokesman reiterated that antibody testing “will play an increasingly important role as we move into the next phase of our response to this pandemic”.
A spokesman for Roche Diagnostics UK told The BMJ that the rollout of the antibody tests to the NHS was “part of the crucial next step in understanding the spread of this virus”.
Meanwhile, a Public Health England spokesman said: “Our evaluations have been completed in record time using the samples and tests that were available to us. We are confident that the volume of samples and methodology was of a high standard.”