Will flight restrictions help as new virus variant emerges?

A new coronavirus variant identified in South Africa is leading to a new round of travel restrictions just as many had finally begun to ease.

The risks of the variant, called omicron, are largely unknown. But the World Health Organization has called it a “variant of concern” and governments around the world are not waiting for scientists to better understand the variant to impose flight bans and other travel restrictions.

On Friday, European Union nations agreed to impose a ban on travel from southern Africa to counter its spread. The 27-nation bloc acted within hours upon the advice of the EU executive, which said all countries needed to be extra cautious in dealing with the variant until it was clear how serious a threat the variant posed.

The U.K. also banned flights from South Africa and five other southern African countries and announced that anyone who had recently arrived from those countries would be asked to take a coronavirus test.

The moves have renewed a debate over whether flight bans and other travel restrictions work to prevent the spread of new variants. Some say at best the restrictions can buy time for new public health measures to be put in place. At worst, they do little to stop the spread and give a false sense of security.

The Africa Centres for Disease Control and Prevention said it strongly discouraged imposing travel bans on people coming from countries where the variant was reported.

DO TRAVEL RESTRICTIONS SLOW THE SPREAD OF THE VIRUS?

They might buy countries more time to speed up vaccination and introduce other measures, like masking and social distancing, but they are highly unlikely to prevent the entry of new variants, said Mark Woolhouse, a professor of infectious diseases at the University of Edinburgh.

“Travel restrictions can delay...