A NEW test to determine whether people have ever been infected with coronavirus is 100 per cent accurate, public health leaders have said, following research from Porton Down scientists.

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% in detecting people who had ever had Covid-19.

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 per cent.

“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.

Mr Johnson said in March that such a test would 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.”

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.