A review of Public Health England modelling which underpins government policy on quarantine for travellers has concluded the work is “flawed” and “significantly underestimates” the effectiveness of testing air passengers.
But while criticising government claims that testing on arrival might pick up only 7% of passengers with asymptomatic Covid infections, the review argues testing might pick up 33% to 63% of all infected passengers – still leaving two in five or more undetected.
The review by economics consultancy Oxera and health data analytics company Edge Health was commissioned by airlines, airports and industry bodies including IAG, Virgin Atlantic Tui, Heathrow, Manchester Airports Group, Airlines UK and Iata.
It also reviewed papers which inform government policy by the London School of Hygiene and Tropical Medicine and the Animal and Plant Health Agency (APHA).
The review argues: “The PHE paper is based on a theoretical model and is not calibrated to real-world data.
“It does not consider actual infection rates . . . and therefore fails to provide any real insight unto the relative risk inbound passengers pose to the UK population.”
The authors report: “Edge Health and Oxera estimate that up to 63% of infected passengers attempting to enter the UK could be prevented from doing so with an on-arrival testing scheme – vastly higher than the 7% figure offered by PHE.”
The report has been submitted to the government’s Global Travel Taskforce which is due to make recommendations to the Prime Minister on a test and release policy for travellers by early November.
Transport secretary Grant Shapps cited the PHE and London School of Hygiene and Tropical Medicine modelling this week when he told the Aviation 2050 summit that testing at borders “could allow a very significant number of people to think they are negative when they are not”.
But the PHE modelling only considers the likelihood of a test on arrival picking up asymptomatic passengers, not all those infected and showing symptoms. It assumes they will not be on a flight.
Shapps told the summit: “Remember, symptomatic passengers should not be travelling. This is about asymptomatic passengers.”
He added: “Germany and France thought they would be able to use a day-zero test and found it is not a feasible thing to do. If we look at the situation in France, we see that.”
Shapps noted the taskforce has already “agreed on a regime based on a single test after a period of isolation, a single test a week after arrival” so it is not clear whether the review of the modelling will have an impact on the taskforce recommendations.
The Oxera and Edge Health review also criticises the PHE and London School of Hygiene and Tropical Medicine for assuming 100% compliance with quarantine, noting recent evidence that “only around 20% of those reporting symptoms of Covid-19 in England report fully self-isolating”.
It argues the effectiveness of testing regimes “should take account of the demographics of infected people in a country of origin and particularly the demographics of those people likely to fly”, and suggests “real-world evidence . . . is currently lacking in the papers’ approach”.
George Batchelor, director of Edge Health, said: “The widely quoted 7% [figure] excludes anyone who is in theory detectable or symptomatic before the flight takes off and leads to an underestimation of the effectiveness of testing on arrival, raising serious questions about its role in informing government policy.”
Michele Granatstein, Oxera partner and head of aviation, said: “All three papers are based on theoretical simulation models. The outputs are only as good as their inputs.
“It’s important that outputs are calibrated with real-world evidence from established airport testing regimes.”
Virgin Atlantic chief executive Shai Weiss said: “The UK government has insisted that testing on arrival at an airport would identify only ‘7%’ of Covid-19 cases.
“Today’s new and independent analysis identifies flawed and outdated assumptions in that modelling, and reveals testing will capture a vast majority of cases rather than the purported 7%, which makes it the right solution.
“The government’s Global Travel Taskforce should consider this new analysis and act on findings to swiftly implement a testing regime which removes 14-day quarantine.”
Granatstein told Travel Weekly: “We re-interpreted the PHE modelling. We will be doing our own modelling, looking at a test on arrival scheme.”
