What Is The Coronavirus Antibody Test – And How Will It Work?

Superdrug is the first high street retailer to announce it will be selling a coronavirus antibody test for £69.

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Superdrug was the first high street retailer to announce it will be selling a coronavirus antibody test for £69.

From 20 May, the test is being sold via the Online Doctor service. The test is “accurate and reliable”, Superdrug said, but the retailer urged those who receive a positive result to continue following social distancing guidelines.

This comes as an antibody test developed by Swiss pharmaceutical company Roche was approved for use in England last week, with an evaluation by Public Health England concluding it’s “100% accurate”.

The tests are different from those being used around the world to see if someone has the actual virus in their system. Instead, the antibody tests – also called serology tests – are designed to check if a person has detectable antibodies in their blood, meaning they will have already had Covid-19, but their immune system has cleared the infection.

Crucially, this means they’ll now have some resistance if they come into contact with the infection again. Antibody tests have previously been labelled a “game-changer” and “completely transformational” by politicians and health experts, but delays in rolling them out have been caused by accuracy concerns.

So how do the tests work – and how will they help slow the spread of coronavirus? Here’s everything you need to know.

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So the test detects antibodies – but can’t people get the virus twice?

To date, there’s been some confusion around whether a person can develop immunity to the virus, or if it’s possible to be infected twice.

The finger prick test works by detecting antibodies – which “will demonstrate if your immune system has cleared the infection”, confirms Professor Trudie Lang, director of the Global Health Network, University of Oxford.

Lang says there were early reports of people getting the virus twice, “but what may have happened is people may have had the same infection again”. This is called recrudescence and is sometimes seen with malaria. It’s the resurgence of symptoms linked to the original infection.

“It isn’t a second virus – it’s the same virus with symptoms coming back again because you haven’t completely cleared it,” she explains.

Unfortunately, there isn’t enough data to say for certain that it’s impossible to get the virus twice. Professor John Newton, national coordinator of the UK Coronavirus Testing Programme, says although it’s unclear to what extent the presence of antibodies indicates immunity, it’s still a “very positive development” that a test is ready.

How will this test help, then?

Prof. Lang believes being able to test if an individual has developed antibodies to the virus will be “completely transformational” in fighting Covid-19 around the world. “We can make sure we’ve got doctors or nurses who can work safely in hospitals,” she says. “People won’t have to isolate unnecessarily at home for 14 days, because you’ll be able to tell very quickly if people have cleared it or not.”

While a cough, fever and breathlessness are the most telltale symptoms of Covid-19, some people infected may have milder symptoms, or even be asymptomatic. “This test shows if you’ve cleared the virus and that’s going to be really important for looking at how immunity is changing across the population and helping us track how the virus is passing,” Prof. Lang explains.

“We’ll have a clearer picture of who’s had it without symptoms and cleared it, and that will help the government in making decisions around when they can lift some of the restrictions that have been put in place.”

The tests could also help identity new people to participate in the NHS’ plasma donation programme. The programme needs people who’ve recovered from Covid-19 to donate their antibody-rich blood plasma, to be used in a potential treatment for patients struggling to fight off the virus themselves.

How will the antibody test be rolled out?

In March, Professor Chris Whitty, who is advising Boris Johnson’s government on tackling the disease, said the tests would first be available for “critical uses”, such as working out whether NHS staff and frontline key workers are immune.

If tests become available for the general population, Prof. Lang says getting the logistics of distribution right will make all the difference.

“We really need these tests to be available at what we call ‘points of care’, which means they’re available in the community so people don’t have to go to a hospital,” she says. “That’s critical and will ramp up the amount of tests that can be done. The whole logistics around it and the availability will be key.”

The new antibody test would not replace the current test to detect Covid-19, but would work in unison with it, she adds. Prof. Lang believes inexpensive access to both tests will be particularly critical in informing health policies in countries where there are currently a low level of confirmed cases.

“This is not just in the UK, every country is struggling with this,” she says. “You have to find the virus, but you have to also find who hasn’t had the virus and where it isn’t. They are two very different jobs – but equally important.”