On Thursday, COVID-19 researchers from Britain’s Oxford University said, rapid lateral flow tests will most likely identify the most infectious COVID-19 cases with higher viral loads; this is despite concerns over the overall sensitivity of the tests,
Along with the roll-out of COVID-19 vaccines, the government has introduced widespread testing, including lateral flow tests, as a key part of its plans to re-open the economy. However, concerns about the accuracy of the tests have led some to question the viability of the government’s plan.
A few scientists have questioned Prime Minister Boris Johnson’s “Operation Moonshot” plans, saying mass testing is likely to be not only very expensive but ineffective as well.
Lateral flow tests are less sensitive than PCR tests, which are considered the gold standard. Lateral flow tests work best among those with higher viral loads.
According to scientists who are looking at data of more than a quarter of a million people who have taken part in the country’s test and trace scheme, the higher the viral load, the more infectious the person. Applying previous estimates of the sensitivity of four lateral flow devices to those findings, the researchers found that the tests would detect between 83.7% and 90.5% of cases leading to onward transmission.
“We know that lateral flow tests are not perfect, but that doesn’t stop them being a game changer for helping to detect large numbers of infectious cases sufficiently rapidly to prevent further onward spread,” said Tim Peto, Professor of Medicine at the University of Oxford.
According to the researchers, it is difficult to ascertain most of those who had been infected asymptomatically, however, “which may contribute substantially to onward transmission.”