A test to see whether someone has already had coronavirus is being developed, but will not be available within days, the UK government's chief medical adviser says.
"I do not think – and I want to be clear – that this is something we'll suddenly be ordering on the internet next week," Prof Chris Whitty said.
An antibody test would let people find out if they had already had the virus.
This could allow doctors and nurses with immunity to return to work.
Earlier, Prof Sharon Peacock from Public Health England had told MPs that 3.5 million antibody tests had been bought and were already being evaluated.
Once shown to be effective, she said "people will be able to order a test or go to Boots to have their finger-prick test done" in the "near future".
But Prof Whitty said these tests hadn't yet been validated.
"The one thing that is worse than no test, is a bad test," he added.
He said experts would also be collecting information from the results of the tests, and needed to make sure "the right people get the test first in order to allow workers to go back".
Prof Whitty said the priority was still to scale up antigen tests – which tell you if someone currently has the illness. These are only available to patients in hospital at the moment, but there are plans to extend them to NHS workers.
During the prime minister's daily press conference, Prof Whitty said that if everyone kept to social distancing rules, the outbreak was "probably manageable" although he conceded it would be a "close-run thing" for the NHS.
"At this point in time, as of today, there is not enormous pressure on critical care compared to a bad or even normal winter's day," he said. The expectation is that pressure will increase over the next two or so weeks.
This message was echoed by infectious diseases expert Prof Neil Ferguson, who was questioned by the science and technology MPs' committee on Wednesday.
He said keeping people inside and increasing NHS staff and beds was likely to prevent intensive care units (ICUs) from being overwhelmed nationally.
Prof Ferguson told MPs that he believed the government's current strategy would mean "in some areas of the country, ICUs will get very close to capacity but it won't be breached at a national level".
"There will be areas of the country which are extremely stressed, but we are reasonably confident – which is all we can be at the current time – that, at the national level, we will be in capacity," he said.
A key government adviser on the country's response to the crisis, Prof Ferguson was responsible for the Imperial College modelling that changed the government's approach and led to stricter social distancing measures being brought in.
These measures are aimed at completely suppressing the spread of the virus and preventing the health service being overwhelmed.
The combination of keeping people in their homes and making more NHS resources available is predicted to bring demand down to a level hospitals can manage.
There would be some resurgence of cases later, Prof Ferguson said, but these local outbreaks could hopefully be kept at a low level through more intensive testing.
He told the committee that the latest research suggested as many as half to two-thirds of deaths from coronavirus might have happened this year anyway, because most fatalities were among people at the end oRead More – Source