New research suggests the current 14-day quarantine policy employed by the UK government for international arrivals, which involves no test, is less effective than previously considered.

Factoring in recent evidence of individuals failing to adhere to the full period of quarantine, the policy is less effective than all other passenger testing regimes currently under consideration.

Just 25 per cent of ‘infectious days’ are prevented through the policy, which has been in effect since July.

Transport secretary Grant Shapps is expected to announce changes to the quarantine regime in the coming days, with a ‘test and release’ system the most likely system moving forward.

This will likely see passengers tested after five to seven days, with quarantine curtailed if a negative results is returned.

New modelling from Edge Health and Oxera applies the latest evidence of quarantine non-compliance and test sensitivity to consider the effectiveness of the current quarantine policy against a range of passenger testing regimes, applying the metric of ‘infectious days screened’.

Using a London School of Hygiene and Tropical Medicine (LSHTM) model as a starting point, the researchers applied recent real-world Covid-19 prevalence rates and air passenger volumes to produce a comprehensive picture of policy options.

When evidence of non-compliance is considered, a single test on arrival would reduce infectious days by 51 per cent - more than double the current policy.

An RT-PCR test, three days pre-departure reduces the infectious days by 36 per cent.

The analysis also finds a ‘test and release’ regime on day three is significantly more effective in minimising infectious days (60 per cent reduction in infectious days with a RT-LAMP test) than the 14-day policy (25 per cent), and also more effective than ‘test and release’ after five days (53 per cent) or seven days (45 per cent) currently under consideration.

Applying the latest assumptions, based on real-world evidence, the three days option balances between ensuring sufficient time for Covid-19 to become detectable and a swift enough result to inform the non-compliant infected individuals in the community of their infectious status, thus ensuring they go into isolation.

George Batchelor, cofounder and director of Edge Health, said: “The current policy of 14-day quarantine is the least effective strategy due to human behaviour, with returning travellers often failing to comply and risking community transmission.

“Our modelling finds a much more effective path in passenger testing, which if it’s applied as a ‘test and release’ regime, performs the best at reducing infectious days after three days quarantine.

“This balances the detectability of Covid-19 and new evidence of quarantine non-compliance.”

Unsurprisingly, airlines were quick to support the research.

Shai Weiss, chief executive of Virgin Atlantic, said: “This new modelling provides yet more evidence that the government is significantly underestimating the efficacy of passenger testing.

“But it also shows that the current 14-day quarantine policy is fundamentally flawed in ignoring human behaviour and compliance with the rules.

“Half a million UK jobs depend on a fully functioning aviation industry; therefore it is vital that policy decisions are based on the latest possible evidence.”

He added: “The ultimate goal must be to safely remove quarantine and it is encouraging that the transport secretary this week recognised effective testing as a way to do this.

“A real-world trial of pre-departure testing is the next step to generate much-needed data and the industry stands ready to deliver this, having already proven it can deliver rapid, point of care tests without diverting vital NHS resources.”