A NEW test is 100 per cent accurate when testing people for Covid-19, according to public health leaders. 

Antibody testing has been called a game-changer by the prime minister, Boris Johnson, as it could reveal how many people have had Covid-19 and may now have a degree of immunity.

Public Health England said last week that scientific experts at its Porton Down facility had carried out an independent evaluation of a new antibody blood test.

It was  developed by a Swiss pharmaceutical company.

The Roche’s serology test was found to be 100 per cent accurate in detecting anyone who ever had Covid-19. 

Professor John Newton, 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.”