What is the coronavirus home test?

It is a finger-prick antibody test that will tell you whether you have been infected with the Sars-CoV2 virus which causes Covid-19. It detects the presence of antibodies in your blood that show your immune system has responded to the coronavirus. It cannot tell you if you currently have the virus; it is for people who have had symptoms and recovered, so that they will know they are no longer infectious and can return to work. People are usually immune to the virus once they have had it. There are case reports of some reinfections, but they are rare.

How does it work?

It looks like a pregnancy test, but includes a small sterile lance to draw a drop of blood from your finger. That is mixed with fluid in the test kit and analysed for the presence of the antibodies. It takes only 10 to 15 minutes. There are a few commercial tests in development. Public Health England has not said which ones are expected to be made available in the UK. Some can be self-read but others will need the help of a healthcare professional. The tests are currently being evaluated in Oxford to ensure they work. Once they are available to the public – the government says key workers will come first – they will be delivered by Amazon and also be available in high-street chemist shops. If there is a cost, it is expected to be minimal.

Is this the test in use at the moment?

No. That’s the standard PCR (polymerase chain reaction) test which is being used in hospitals to find out whether patients who are severely ill have Covid-19, so they can be treated appropriately. It tests for current infection and cannot tell you if you have had Covid-19 in the past. The government has said it wants to increase the numbers tested to 25,000 a day, but the last daily figure was just under 6,500. However, the pharmaceutical giant Roche has signed a deal to help, a testing centre has been opened in Milton Keynes, and the number of tests is supposed to rise to 10,000 within days and then 25,000. These will be mostly hospital patients as now, with further upscaling to 100,000 to reach key workers with symptoms.

What other tests are needed?

A seroprevalence test. This is a blood test carried out in a systematic way to understand the extent of the epidemic in the UK – the scale and the characteristics of people who have become ill and recovered.