THOUSANDS of people could be infected with coronavirus but have shown no or very few symptoms because their body has quickly created the right antibodies to fight the virus.
The Government has been fast-tracking the science to find these special people and has bought 3.5 million antibody tests which could reveal whether someone has already had Covid-19 and developed some immunity.
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Boris Johnson branded the tests a “game-changer” and said they would allow key workers – including NHS staff – to return to work as soon as possible.
On Wednesday, Professor Sharon Peacock, director of the National Infection Service at Public Health England (PHE), told the Science and Technology Committee that 3.5 million tests had been bought and would be available in the “near future”.
She explained a small number of tests would be tested in a laboratory before being distributed via Amazon and in places like Boots.
However, Professor Chris Whitty – England’s Chief Medical Officer – later said the accuracy of the tests needed to be properly tested before they were made available for public use.
So, what are antibody tests and how do they work? Here we explain in more detail…
How can I get tested for coronavirus?
Currently, there are two types of tests for Covid-19 – one is a nasal swab that tells you if you have the virus at present, known as antigen test.
The other, known as an antibody test, tells you if you have had a past infection and is carried out using a finger-prick test.
If you are a member of the public feeling ill at home, you most likely will not get the antigen test telling you whether you have coronavirus.
There is a small amount of random sampling going on via GP surgeries but most testing is of patients admitted to hospital.
The NHS is prioritising the testing of seriously ill people in hospital to help inform treatment but also to collate numbers of those affected.
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The Government hopes to start rolling out testing for Covid-19 to NHS frontline workers in the next few days.
A large part of the workforce may be self-isolating at home unnecessarily, either because they have symptoms or somebody in their house does.
Knowing whether these NHS workers truly have coronavirus could help them get back to work quickly – which the NHS desperately needs.
There has been no announcement regarding testing for other key workers.
The NHS is aiming to get to 25,000 of these tests per day, with the ultimate aim being several hundred thousand.
What is an antibody test?
When a person gets infected with a virus, the body starts making specially designed proteins called antibodies to fight the infection.
After they recover, those antibodies float in the blood for months, maybe even years.
So a test that specifically looks for antibodies will be able to tell whether you’ve already been exposed to Covid-19.
Anyone who has already had the illness is presumed to be immune to getting it again.
The check that has been developed for Covid-19 is a finger-prick blood test, with the samples sent to laboratories and results available within a few days.
The tests are being developed by several different firms and Public Health England (PHE) is also working on its own test.
They still need to be validated to ensure they give accurate results.
How does it work?
Dr Hilary Jones, a GP and resident doctor on Good Morning Britain, explained that it’s “almost like a pregnancy test, except you need a drop of blood”.
Showing how it works, he said that a blood droplet goes into the well – a small hole at the bottom – followed by two drops of buffer solution.
He continued: “This migrates up the filter to chemicals which create something called an immunoassy.
“It’s looking for particles that come from the virus.”
Pointing to the letter C on the side of the test, Dr Hilary explained that it stands for the word control.
“There is a little red line next to the C mark – that’s a control, which is a valid test and means the test has worked.”
Dr Hilary said that the test is looking for antibodies, which are produced by the immune system to fight off the infection, and detecting them would mean you’ve had coronavirus.
He added that there are two types of antibody that the body makes when we’re exposed to the virus – IGG and IGM.
“IGG antibodies take longer to develop after an acute infection,” he said.
“They probably come in within 14 days and peak at five weeks and can last six months.
“IGM antibody are created within seven days of an acute illness and peak around two to three weeks.
“So, what this test shows – and mine was negative – it shows that you have either had the infection already and you have antibodies and are immune, or you haven’t been exposed to the virus.”
When will they be available?
Millions of the tests could be made available within days, according to Professor Sharon Peacock, from Public Health England.
She told MPs on the Science and Technology Committee that mass testing in the UK would be possible within days and evaluation of the finger-prick blood test should be completed this week.
Prof Peacock also revealed that they could be bought from the high street at Boots or via Amazon.
However, England’s Chief Medical Officer, Professor Chris Whitty, later sought to play down the suggestion that tests would be available within days, saying the public would not be buying the tests on the internet next week.
Boots urged people not to go into its stores looking for the tests.
Dr Hilary also said that the test kits need to be themselves tested thoroughly before being brought out in a controlled fashion.
He warned: “If we have this test they have to be really accurate and specific. There’s no point having unreliable tests.
“People could go back to work without immunity and causing more harm than good.”
