A randomly selected group of 100,000 people in England will be tested for Covid-19 in an attempt to quantify whether transmission levels of the virus are low enough to exit the lockdown.
The tests, next week, will provide a national snapshot of the proportion of those infected with the virus ahead of a planned review of restrictions on 7 May.
Prof Ara Darzi, the director of the Institute of Global Health Innovation at Imperial College London, which is running the study with the pollster Ipsos Mori, said that – short of a vaccine – testing represented the only way out of the lockdown.
“But the testing landscape is like the Wild West with no rules, no standards and widely varying reliability,” he added. “With this ambitious programme, the biggest in England, we aim to establish a viable testing programme on which the government can rely.”
The 100,000 people, selected from 315 local authorities across England, will be invited to carry out home tests that will show whether they are currently infected with the coronavirus. The team plans to repeat the exercise in four to six weeks’ time – or at a point when lockdown restrictions are being eased – to capture early signals that any resurgence is occurring.
“You need the big numbers to be sure that you find low levels of the virus in the community,” said Prof Graham Cooke, a member of the Imperial College team.
In the second part of the programme, a number of different antibody tests will be assessed for their accuracy and ease of use at home. The tests will first be carried out on volunteers from Imperial Healthcare NHS Trust who are known to have had the virus, to establish their accuracy. Three hundred public volunteers will also be given a sample test to self-administer, which requires them to place a fingerprick of blood in a cassette, add a dye and read off the result, to assess how well people are able to perform the tests at home.
Initially only patients in hospital could get tests in the UK. Then testing was expanded to NHS staff and care home staff. Now up to 10 million essential workers and their families who are showing symptoms of coronavirus can apply for a test via a government website.
The list of essential workers is the same as the one used to allow the children of key workers to carry on going to school during the lockdown. In addition to health and social care staff, the list includes teachers, judges, some lawyers, religious staff, and journalists providing public service broadcasting.
Also included are local civil servants, police, armed service personnel, fire and rescue service staff, immigration officers and prison and probation staff. Some private-sector staff also qualify including vets, those in food production, essential financial services and information technology, as well as those working in the oil, gas, electricity and water sectors.
If the tests are shown to be sufficiently accurate and usable, they will be distributed to larger cohorts, with the potential to roll out the antibody testing to 100,000 people later this year, to provide an indication of the prevalence of Covid-19 immunity.
Previously the government had floated the possibility of making antibody tests readily available to the public through Boots and Amazon, and ordered millions of commercial kits.
It had to backtrack on this proposal after the best performing of these only picked up antibodies about 70% of the time. However, Cooke said that some of the assessments of the accuracy of these tests may have been overly pessimistic, because lab-stored serum was used, rather than blood samples taken directly from individuals.
He added that some of the tests might not be sensitive enough to provide results for individuals, but could still provide a broad picture of what proportion of the population had been infected.
James Bethell, a health minister, said: “Understanding more about the current spread of coronavirus and the prevalence of antibodies is a vital part of our ongoing response to this pandemic. This ambitious new testing programme will help us track the rate of the infection now.
“And, crucially, it will help identify an antibody test that is accurate and easy to use, and which can give us an indication of how many people have already had the infection. This information will inform the future action we take to manage the spread of the virus, including the development of new tests and treatments.”
