A new test to determine whether people have ever been infected with coronavirus is 100% accurate, public health leaders have said.
Prime Minister Boris Johnson has previously called antibody testing a “game-changer” as it may reveal how many people have had Covid-19 without any symptoms and so may be immune.
Any reliable test may help speed up measures to ease the lockdown because people could go back to work confident they were not likely to get it again.
Public Health England (PHE) said last week scientific experts at its Porton Down facility had carried out an independent evaluation of a new antibody blood test developed by a Swiss pharmaceutical company.
The examination found Roche’s serology test was “highly specific” and had an accuracy of 100%.
Professor John Newton, national coordinator of the UK Coronavirus Testing Programme, said although it was still unclear to what extent the presence of antibodies indicated immunity to Covid-19, it was a “very positive development”.
He added: “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%.
“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.”
The antibody test is designed to help determine if a patient has been exposed to the virus that causes Covid-19 and whether they have developed antibodies against it.
The detection of these antibodies could help to indicate if a person has gained immunity against the virus.
Johnson said in March: “The great thing about having a test to see whether you’ve had it enough, is suddenly a green light goes on above your head and you can go back to work safe and confident in the knowledge that you are most unlikely to get it again.
“So for an economic point of view, from a social point of view, it really could be a game-changer.”
A Department of Health and Social Care spokeswoman said: “We are exploring the use of antibody testing across the NHS and ultimately the wider public.
“We are delighted that devices are progressing through validation, and are actively working on our plans for rolling out antibody testing and will make announcements in due course.”
UK health secretary Matt Hancock last week said the UK was in talks with Roche about a “very large-scale roll-out” of coronavirus antibody testing.
The findings come as Dr Mike Ryan, executive director of the WHO’s health emergencies programme, told the FT’s Global Boardroom digital conference no-one could predict when the disease would disappear.
He said: “We have a new virus entering the human population for the first time, and therefore it is very hard to predict when we will prevail over it.
“And it is important to put this on the table – this virus may become just another endemic virus in our communities. And this virus may never go away.
“HIV has not gone away, we’ve come to terms with the virus and we have found the therapies and we found the prevention methods, and people don’t feel as scared as they did before and we’re offering long healthy life to people with HIV.”