Covid: Why hasn't the UK banned all international flights?

From Monday, everyone entering the UK must go into quarantine after the government abandoned its travel corridors.

The country has also extended a travel ban to South America, Portugal and many African countries, amid concerns about new, potentially more infectious variants of coronavirus.

But it has never banned international travel altogether.

Why didn't the UK shut its borders before it had any cases?

Between January and March 2020, the UK introduced some measures to try to protect itself from the new virus.

Quarantine was imposed on 273 people travelling from Wuhan in China, where the first outbreak was seen.

Others from "high-risk countries" including China, Iran and Northern Italy were asked to voluntarily isolate for 14 days.

An inquiry into the pandemic suggested it was understandable that the Government "did not consider it practical or effective simply to restrict flights" at that time, partly because there were so many British residents trying to get home.

These self-isolation requirements were withdrawn on 13 March, 10 days before the UK went into lockdown.

The 10-day gap in restrictions led to thousands of UK infections through cases arriving from Europe.

"The government's failure to have proper quarantine measures in place in March as the infection was spreading fast was a grave error and meant Covid spread faster and reached more people," Yvette Cooper, chair of the committee of MPs behind the inquiry said.

A recent study found that the virus was introduced to the UK "well over a thousand times in early 2020" with a third of transmission chains brought in from Spain, followed by 29% from France, neither of which faced any kind of restrictions. China accounted for just 0.4% of imported cases.

What were the government's reasons?

The Home Office said the committee behind the inquiry was "incorrect in their assertions".

It said keeping borders open helped businesses to maintain international connections, boosted the economy and meant people could still travel for essential reasons.

It argued that by mid-March there was "significant transmission" in the UK and any extra travel restrictions at that time would have had a "very marginal" impact.

At a meeting in early February , the government advisers Sage suggested that cutting the number of infections entering the UK by half would only delay the epidemic by five days.

The scientists estimated that a 95% reduction in imported cases, which would have required "draconian" travel restrictions, would have pushed things back by a month.

'Not a silver bullet'

Mark Woolhouse, professor of infectious disease epidemiology at the University of Edinburgh, said that by far the best time for the UK to have introduced a ban would have been back in January, when the virus was first identified in China.

"It's actually a very disruptive intervention, so you have to balance the cost and benefits," he said.

"There's a perception that closing our borders is a magic wand - it might make some difference but it is not a silver bullet."

Arguments for a travel ban could be made around the new variants of coronavirus, he suggested, but it was far from certain.

Are other travel restrictions effective?

The UK currently has a number of travel restrictions in place. Travel is only permitted for essential reasons and most people entering the UK must quarantine for 10 days, or fewer if they test negative after five days.

Direct flights from parts of the world with new coronavirus variants are banned.

From Monday, people entering the UK must show evidence of a recent negative coronavirus case before boarding their flight, while quarantine will be extended to countries that were previously exempt.

An Office for National Statistics pilot survey in October suggested that only two thirds of arrivals to the UK were definitely following self-isolation rules. This figure may be lower as self-isolating is a legal requirement, and breaking the rules can be punished with a fine.

For this reason, Prof Woolhouse is in favour of mass testing.

"A testing regime people comply with is much more effective than a quarantine regime that they don't," he said.

What have other countries done?

Australia and New Zealand both closed their borders to almost all visitors in March, although travellers from New Zealand have been allowed to enter most Australian states without quarantine since October. So far though, this has been a one-way agreement - meaning they must do 14 days of managed isolation on their return to New Zealand. And Australians are not allowed into New Zealand at all, unless they have an exemption.

Anybody who arrives in Ireland must fill in a passenger locator form and if they fail to do so they could be fined €2,500 (£2,200) or imprisoned for up to six months, or both. Passengers arriving from South Africa or the UK must have tested negative for the virus within 72 hours of their arrival in Ireland and are still required to isolate for 14 days.

Foreign nationals from most countries are not currently allowed into Japan unless they are residents of the country. Even then, they have to provide evidence of a negative test in the last three days, have another test on arrival and then isolate for 14 days. Travellers from the UK or South Africa must spend the the first three days of isolation in a government facility and take another test on the third day.

The US restricted travel to and from China in February and advised citizens against all international travel in March. Since then, travellers who have entered Brazil, China, Iran, Ireland, the UK and the European Schengen travel area have been banned from entering. From 26 January, anybody hoping to enter the country will have to have tested negative for the virus before their departure.