The hope that antibody tests against coronaviruses could help the UK end its foreclosure has been dealt a serious blow – after the World Health Organization questioned whether they offered a guarantee d ‘immunity.
The UK has placed antibody testing – which checks to see if anyone has had Covid-19 – at the center of a possible “return to work” plan to resume normal life.
But experts said they would not prove if someone is protected from reinfection.
The UK test coordinator also warned people not to buy private tests.
The government has already paid for three and a half million antibody tests, but has yet to find one reliable enough to use it – and points out that it will not approve the use of any test until it will not be sure that its results will be fully dependent.
Professor John Newton said the public should not buy unapproved antibody tests until a work test is approved.
“We innovate every day with this work and I am confident that this major research effort will make a breakthrough,” he said of efforts to develop a valid serological test, which measures antibody levels in plasma. blood.
“Until then, please do not purchase or pass unproven tests. They may not be reliable for your intended use; they can misread and put you, your family and others at risk. “
He added: “As soon as we find a test that works for this purpose, we will be able to deploy it across the country as a return-to-work test. “
Speaking in Geneva, Dr Maria van Kerkhove of the World Health Organization (WHO) questioned the benefits of rapid serological testing due to a lack of evidence regarding immunity to coronaviruses.
She said: “There are many countries that suggest using rapid diagnostic serology tests to be able to understand what they think is a measure of immunity.
“At this time, we have no evidence that the use of a serological test can show that an individual is immune or protected against reinfection. “
She added, “These antibody tests will be able to measure this level of seroprevalence – this level of antibody, but that doesn’t mean that someone with antibodies means they’re immune. “
Dr van Kerkhove said it was “a good thing” that so many tests were being developed, but added: “We have to make sure they are validated so that we know what they say they are trying to measure, they actually measure. “
His colleague, Dr. Michael Ryan, said that the antibody tests also raise ethical questions.
“You might have someone who thinks he is HIV positive [have been infected] and protected in a situation where they can be exposed and in fact they are susceptible to the disease, “he said.
On Friday, the UK announced 847 new coronavirus-related deaths in hospitals, bringing the total to 14,576.
Health Secretary Matt Hancock said on Friday that swab tests – which assess whether someone is currently infected with coronavirus – will soon be deployed to other key workers, including police, prison staff and firefighters .
He added that some 50,000 NHS workers have been tested for the virus so far.
However, he said it was “frustrating” that there are currently more capacity tests every day than the numbers being used. As of Thursday, 38,000 tests were available but only 21,000 have been completed, prompting government release of who will be eligible for the test.
The government has an overall target of 100,000 tests per day by the end of April.