Is this new 90-minute test the key to defeating Covid?
Victoria Lambert and Luke Mintz meet the British scientist behind the breakthrough
Professor Chris Toumazou looks back on the early stages of lockdown as easily the most “intense, surreal” period of his life. A widely respected bioengineer at Imperial College London, he spent most of his waking hours in late February and March on hospital Covid wards.
His aim was to produce a safe, effective test for Covid-19 that would transform Britain’s approach to the virus by delivering a result in hours, rather than days. His work meant months without visiting his family, who live in Australia; he even had to miss his daughter’s 10th birthday
(she has learning difficulties and “missed me a lot”, he says).
But Prof Toumazou’s efforts finally bore fruit last week, when the Government placed an order for 5.8million of his
‘The fact this test detects flu as well... will be hugely beneficial as we head into winter’
rapid Covid-19 test kits, to the tune of £161million. Ministers think the new tests will revolutionise their response to the virus by returning a result within just 90 minutes, seeing off the danger of another national lockdown by enabling them to test whole towns or cities to contain local outbreaks. Until now, tests have had to be sent off to laboratories, often by post, where they take a minimum of four hours to process. A 24-hour turnaround time is seen as the “gold standard”, experts say. But Prof Toumazou’s test, along with another test supplied by Oxfordshirebased Oxford Nanopore, can be processed on the spot in portable machines, at a cost of just £20 per kit.
They are likely to be used to screen travellers at airports, and teachers will be randomly tested to determine whether reopening schools in September has any effect on transmission rates. The tests can detect flu as well as Covid, meaning people with Covid-like symptoms will know whether they are suffering from the more common illness and can avoid self-isolating. It follows a successful pilot of the 90-minute tests in Southampton.
“I’m excited because I’ve always been passionate about trying to bring these sorts of testing technologies to the consumer,” says Prof Toumazou, who wants to “demystify” the testing process and dispel the idea that a Covid test can only be carried out by a white-coated scientist in a faraway lab.
Prof Toumazou’s 90-minute kit uses a type of PCR (polymerase chain reaction) technology, which looks for the virus’s RNA. Every living cell has both DNA and RNA in it: DNA provides the code for the cell’s activities, while RNA converts that code into proteins to carry out cellular functions. Coronaviruses have large quantities of easily identifiable RNA.
It is a technology that Prof Toumazou has been perfecting for much of his career. Born to Greekcypriot parents, he assumed he would end up running a Greek restaurant after leaving school with no O-levels. But he was always fascinated by history’s great inventors, and sought out a technician certificate, followed by a degree in engineering from Oxford Polytechnic, and then a
PHD.
By age 33, he was Imperial’s youngest ever professor. His son, Marcus, lost both of his kidneys at the age of eight due to a genetic predisposition to renal failure. Marcus recovered, but the episode focused Prof Toumazou’s mind on the importance of genetics in determining our health. If they had known about Marcus’s kidney issues from a younger age, could dietary changes have helped to avoid his illness?
And so last year he launched Dnanudge, an engineering start-up based at Imperial College, which analyses your DNA and then tells you your vulnerability to various genetic ailments, such as heart disease, Alzheimer’s and diabetes. Using a cotton bud, patients are asked to scrape cells from the inside of their cheek, and place them in a white cartridge, about an inch long. The cartridge is then inserted into a box (about the size of a CD player), which scans their DNA for signs of danger.
The idea was to give each patient better control over their own health by providing a personalised list of dos and don’ts, tailored to each patient’s genetic profile – a person predisposed to high blood pressure would be told to eat less salt, for example.
Then Covid-19 came along, paralysing healthcare systems across the world and sending country after country into lockdown, and Prof Toumazou began to wonder whether his cartridges could be adapted to scan RNA rather than DNA, so they could detect SARS-COV-2 – the virus that causes Covid-19.
“There was a moment when we looked at the cartridge and thought, ‘What if?’,” he remembers. “The cartridge was already sophisticated, as it has been designed to look at small areas of DNA and separate one small mutation from another. But the virus is binary – it is there or not there.”
The starting gun was fired on March 1, when Public Health England published a list of the relevant genes to encourage scientists from across the country to get involved in developing a test. Prof Toumazou’s team got to work, moving in and out of Covid wards to look at how his cartridges fared against more cumbersome lab-based technology.
Maternity wards were particularly grateful because mothers displaying symptoms could be screened quickly before birth, allowing them to hold their newborns at once rather than having to wait 48 hours for results to come back from a lab.
As well as delivering fast results, Prof Toumazou’s 90-minute test also promises to be far more accurate than traditional lab-based tests. Currently, about two in 10 Covid tests produce a “false negative” result, he says – but his test virtually eliminates this risk through an inbuilt control that tells you whether any human RNA was collected (if it wasn’t, the test has clearly failed). “If the test shows up as not working, you know in about an hour and can just re-test.”
The new tests have clearly created a buzz in Whitehall, with Government sources now making grand claims about their ability to test whole towns and cities in a matter of days. Matt Hancock, the Health Secretary, said that 90-minute turnaround times will “help to break chains of transmission quickly”, adding: “The fact these tests can detect flu as well as Covid will be hugely beneficial as we head into winter.”
But given the Government’s previous difficulties in “ramping up testing”, as they put it, can we be sure it isn’t more headline-grabbing bluster? “There’s been a lot of negativity about the Government’s response, and whether they were too slow to react,” says Prof Toumazou.
“But they had tests like ours and others being validated over several months. There’s no bottleneck in terms of production,” he adds.
“The cartridge is a bit like a printer cartridge, it’s very small and scalable, you can make millions of these things, and come the end of the year we should be producing about a million cartridges per month – bang in the middle of flu season.”