The Telegraph understands that the Department of Health is in negotiations with the Swiss healthcare company Roche to buy millions of the kits.
The accuracy of the test was given approval by experts at PHE’s Porton Down facility last week.
On Wednesday night, Roche said it stood ready to provide hundreds of thousands of laboratory-based tests to the NHS each week. A Government source said: “We want to get our hands on as many of these as possible.”
The development of an accurate antibody test has long been seen as key to helping Britain get back to work, with Boris Johnson having previously described such tests as “game-changing”.
Scientists believe people who produce antibodies after having coronavirus may develop immunity to catching the virus again, making them safe to return to work. The Government has suggested the tests could be used to grant “immunity passports”, freeing people from restrictions on an individual basis.
The UK has rejected previous tests over reliability concerns, but PHE has confirmed Roche’s claim that its test is accurate in 100 per cent of cases.
Professor John Newton, the national coordinator of the UK Coronavirus Testing Programme, said: “We were confident that good quality antibody tests would become available when they were needed.
“Last week, scientific experts at PHE Porton Down carried out an independent evaluation of the new Roche SARS-CoV-2 serology assay in record time, concluding that it is a highly specific assay with specificity of 100 per cent.
“This is a very positive development, because such a highly specific antibody test is a very reliable marker of past infection. This in turn may indicate some immunity to future infection, although the extent to which the presence of antibodies indicates immunity remains unclear.”
On Wednesday night, Jeremy Hunt, the chairman of the health select committee and a former Health Secretary, said: “This is potentially very exciting news for people who work in the NHS and care sector who have been most exposed to the virus.
“If we can establish that antibodies give you immunity, it would mean that you can go back to work safely. As soon as we can be certain that antibodies give you long-lasting immunity, I would expect significant orders to be placed.”
Steve Brine, a former health minister, described the move as a “potential game-changer,” telling The Telegraph it could help improve public confidence to return to work as the lockdown is lifted.
Mr Brine added that if the scientific advice suggested antibodies could provide immunity, or a high level of it, the Government should move quickly to purchase enough kits for the UK population.
“I’d want to be confident of the science behind it, and what’s more confident than the epidemiology which tells us that once you’ve had the antibody you can’t get it again?” he said.
“There is still no consensus in the scientific community, but potentially it is a game-changer – not just for frontline workers but also for the wider population who could take great confidence from this to turn baby steps into bigger steps.
“The truth is it is far harder to get out of lockdown than it is to get in because public opinion – partly because we saw our Prime Minister nearly lose his life over this – is quite circumspect. Something like this could give people confidence, providing the science is published and agreed that it works [by indicating immunity].”
Professor James Naismith, of the Rosalind Franklin Institute at Oxford University, said: “This is really good news. It will give us a much better idea of how many people have been infected, and that number will tell us now many people are vulnerable to a second wave. If lots of them are the young Tube-travelling population, for example, then there will be less fuel for the fire.”
Geoff Twist, the managing director of Roche Diagnostics UK and Ireland, said the firm was working with the Government and the NHS to enable the test to be rolled out across the UK as soon as possible.
Matt Hancock, the Health Secretary, last week disclosed that officials were holding discussions with the company about a “very large-scale rollout” subject to accuracy being confirmed. Mr Hancock had previously promised that widespread antibody testing would be available by the middle of May.
The capacity could transform scientists’ understanding of how much potential immunity exists in the country, helping them chart a safe route out of the lockdown restrictions.
Ministers hope the antibody tests will be rolled out within weeks and enable the Government to reach Mr Johnson’s goal of testing 200,000 people per day. Germany has already signed a deal to buy five million tests each month.
The Elecsys laboratory-based test requires a blood sample to be taken by a health professional. Blood serums are obtained, to which reagents are added, and then examined in machines known as cobas e analysers, already widely installed in NHS labs across the country.
The Telegraph has also learned that the NHS is sending samples of donated blood for Covid-19 antibody tests as part of PHE’s prevalence study. NHS Blood and Transplant, which oversees donations, indicated that donors whose samples test positive are not informed of the result.
Ministers were heavily criticised earlier in the virus crisis after promises that home testing fingerprick tests would be available “within weeks” backfired.
An order of 3.5 million by the Health Secretary was cancelled after they were found not be meet basic Medicines and Healthcare products Regulatory Agency (MHRA) standards. The Roche test received its CE mark of health and safety approval from MHRA on April 28.
Because Covid-19 is a new virus, it is not known for sure whether people who have been infected gain immunity, although an ongoing NHS trial has indicated that an “overwhelming majority” of patients produce antibodies. It is also not known how long immunity lasts.
Towards the beginning of the crisis, antibody testing was touted as a crucial tool for leaving lockdown.
However, as the difficulty of securing a reliable test became clear, ministers stressed the importance of PCR testing – indicating current infection – along with aggressive track and trace. Mr Hancock has promised to recruit 18,000 volunteers to help with the contact tracing effort.
It emerged on Wednesday that the pharmacist Boots is advertising for an army of hundreds of unpaid volunteers to test people for coronavirus. An advertisement on the company’s website said it is looking for 1,000 current staff and volunteers to work at least 32 hours a week as swab testers across the UK.
In briefing documents submitted to the Government’s Scientific Advisory Group for Emergencies (Sage) last month, scientists warned that “immunity passports” could cause discrimination, with employers favouring those with a positive antibody test.
The experts said people may deliberately infect themselves in order to be allowed back to work.