As it works to get more shots into arms across the country, the U.K. government announced that it would make routine, rapid COVID-19 testing available for free to everyone in England.
The plan includes two tests per week starting April 9, with results expected at home within 30 minutes, regardless of whether a person is showing symptoms. The plan is part of the country’s road map to lift wider lockdowns by the end of June, depending on the continuing rollout of vaccines and lower rates of infections and hospitalizations.
The announcement also comes as the country considers implementing COVID-19 passports as a requirement for entering large public gatherings, such as soccer matches and concerts, according to the Associated Press. Information on the passport would include testing status and whether the holder has received the vaccine or whether they’ve recovered after a coronavirus infection in the previous six months.
“Around one in three people who have COVID-19 show no symptoms, and as we reopen society and resume parts of life we have all dearly missed, regular rapid testing is going to be fundamental in helping us quickly spot positive cases and squash any outbreaks,” Matt Hancock, secretary for health and social care, said in a government release.
However, the accuracy of lateral flow diagnostic tests has been called into question.
A recent Cochrane review found that rapid, point-of-care tests, including antigen diagnostics, can vary in sensitivity over time and potentially be the most accurate during the first few days of an infection while viral loads are highest.
Because of that variability, the tests could be useful as a way to confirm active cases where molecular lab tests are unavailable, according to the researchers, but they said they could find virtually no evidence confirming their effectiveness at screening large numbers of people on a regular basis.
Meanwhile, across 64 studies encompassing more than 24,000 samples, antigen tests only correctly identified 58% of hidden COVID-19 infections among people who showed no symptoms.
“The effectiveness of mass screening using these tests will only be established through outcome studies, such as cluster‐randomized community trials,” the researchers wrote.
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In addition, while the U.K. government said its tests had a rate of less than one false-positive result among every 1,000 performed, when multiplied at twice per week across England’s population of more than 55 million people, incorrect readings could still number in the tens of thousands.
"Mass testing is a scandalous waste of money," Allyson Pollock, professor of public health at Newcastle University, told the BBC. "When the prevalence rate of coronavirus falls as low as it is at the moment, then an increasing proportion of cases are likely to be false positives meaning that cases and contacts will self isolate unnecessarily."
The U.K. has previously spent more than £800 million, or more than $1.1 billion, to help set up rapid testing programs capable of screening millions of people per day, including through a pilot project in the city of Liverpool—but the tests themselves could give high rates of wrong results, according to a January report from the Guardian.
That money includes the purchase of more than 380 million rapid, lateral flow tests from Innova Medical Group. An analysis by researchers at the University of Oxford found those tests were more accurate depending on who was using them.
When testing was performed by laboratory specialists, an average of 79.2% of positive cases were correctly identified—but that number dropped when tests were used by healthcare workers in real-world settings and among people swabbing themselves at home, down to 73% and 57.5%, respectively.
Writing in the British Medical Journal, contributor Ingrid Torjesen said lateral flow tests such as Innova’s should be used under strict parameters—including for people who cannot work from home, such as healthcare providers, teachers and students. The tests should not be used to clear people who have been exposed to a confirmed case or to shorten the amount of time spent in quarantine, unless used alongside a gold-standard PCR diagnostic, Torjesen said.