UK

When can I get the new Covid-19 antibody test and should I use it if I've never had symptoms?

A test to find out whether people have been infected with coronavirus in the past has been approved by health officials and could be rolled out within weeks.

Here, we answer the key questions surrounding the new test.

– Can I get the new test?

Not yet. The British government plans to first roll out the test to front-line workers such as those in health and social care.

It is hoped the test will become available to the wider public, although it is unclear whether this will be via the NHS or through commercial websites.

Roche says it will be able to provide hundreds of thousands of antibody tests to the UK every single week.

If it proved people were definitely immune, people could safely go back to work and could socialise with other people without fear of catching or spreading the virus.

– What is the new test?

Pharmaceutical giant Roche has developed a test which can tell whether somebody has ever had coronavirus.

The test involves taking a small sample of blood and testing it for antibodies which will indicate exposure to coronavirus.

Public Health England (PHE) has evaluated the new Roche test and has approved it as being safe and reliable for widespread use.

– How reliable is it?

Very. The test picks up 100% of people who have had coronavirus.

This means it has 100% sensitivity.

It also has a specificity of over 99.8% – meaning it picks up virtually all people who have not had coronavirus.

A test that is 100% specific means all healthy individuals are correctly identified as healthy – there are no false positives.

– What if I’ve never had any symptoms of Covid-19?

It doesn’t matter.

Experts believe a proportion of people who have had Covid-19 never actually develop symptoms.

The new test can identify people who have had coronavirus even if they have never had any indication they are infected.

– If the test shows I’ve had Covid-19, am I now immune from it?

Scientists are unsure and there is still a lot to learn about coronavirus.

Experts believe that while the presence of antibodies indicates a level of immunity, it is unclear whether people are completely protected and how long any immunity lasts.

There has been some suggestion that immunity could last for two to three years but more work needs to be done.

– How does it work?

A blood sample is processed by centrifuging or spinning it using automated equipment already installed at NHS sites across the UK.

This makes a part of the blood called the serum, which contains antibodies for all sorts of things, rise to the top.

Special chemicals called reagents are then added to it and if Covid-19 antibodies are present, the chemicals trigger a light reaction which a machine detects.

– Is it a potential ‘game changer’ as Boris Johnson has suggested?

If it proved people were definitely immune, people could safely go back to work and could socialise with other people without fear of catching or spreading the virus.

On a large scale, it could also provide essential information for tracking where the disease has been and forecasting future hot spots.