Ministers are considering ordering millions of antibody tests developed by researchers in Britain despite conceding that there are still concerns over the reliability of the home test kits.
The foreign secretary, Dominic Raab, confirmed on Sunday that the government was assessing the new antibody kits in the hope of using them to reveal how many people have recovered from the infection and presumably acquired some level of immunity.
If the tests are accurate enough, they could potentially identify individuals who are at least in part protected against the virus, and shed light on how much of the population has been exposed.
But Raab told the BBC’s Andrew Marr show that it was still unclear whether the tests were reliable enough to roll out at scale. An ideal test would detect all those with antibodies to the virus and produce negative results for anyone who has not been infected.
A flawed test that mistakenly suggests people are immune when they are not could be extremely dangerous if those people returned to work in care homes or hospitals.
According to a report in the Mail on Sunday, the government has ordered up to 50m new antibody test kits developed by the newly formed Rapid Testing Consortium at Oxford University. But Raab cast doubt on that claim, telling Marr he was not sure if they had been ordered, and that doubts remained about their quality.
The consortium’s leader, Jonathan Allis, told the Mail on Sunday: “We are close to picking up 100% of all cases where people have antibodies. Now it is just a question of scaling up the manufacturing process.”
The Guardian understands that the test has not passed official performance criteria drawn up by the Medicines and Healthcare products Regulatory Agency (MHRA).
The report described the test as costing £10 and taking 20 minutes to reveal whether or not people have antibodies in their blood that can fight the coronavirus. It would analyse a pinprick of blood and show two lines for a positive test result.
Those using the test will be asked to send a photo of the results to a central database. If the test is deemed to be effective, the consortium believes it could produce 1m per week by the summer, and up to 50m by next year, the report added.
But some senior scientists warn that the focus on home testing kits for antibodies is unhelpful. Sir Jeremy Farrar, director of the Wellcome Trust and a member of the government’s Scientific Advisory Group for Emergencies (Sage), tweeted on Sunday that while research on rapid and reliable antibody tests should continue apace, they were a “distraction until we have one”. The focus now, he said, must be on a massive increase in virus testing, lab-based checks for antibodies, isolation of the infected, contact tracing and clinical care.
Earlier this month, Martin Hibberd, a professor of emerging infectious diseases at the London School of Hygiene and Tropical Medicine, pointed out that fingerprick tests for antibodies were rarely reliable for infectious diseases, and urged ministers to pour efforts into far more reliable lab-based antibody tests called Elisas, which are already being used by Public Health England and others to screen blood for Covid-19 antibodies.