By Rachel Moss
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 latest 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.
“The working assumption with the evidence we have so far is that it’s very unlikely you can get the virus again,” she tells HuffPost UK. “There were some 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, she explains, 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 says.
How will this new test help, then?
Prof. Lang says 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 among the known symptoms of Covid-19, evidence suggests some people infected may have milder symptoms, or even be asymptomatic. Therefore, this antibody test could help paint a more accurate picture of the disease and how it’s spreading.
“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.”
Scientists at the Icahn School of Medicine at Mount Sinai are developing these antibody tests. On Wednesday, the team shared their findings. Professor Florian Krammer, a virologist at the school, told Science Mag the test could also pave the way for new treatment, by allowing recovered patients to donate their “antibody-rich serum” to help treat critically ill patients.
How will the antibody test be rolled out?
The antibody test is still in development and it’s unclear how it will be rolled out, but once it’s ready, Prof. Lang says getting the logistics 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, because at the moment they’re taking up a lot of hospital care workers’ time. 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 places where there are currently a low level of confirmed cases, such as Africa.
“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.”