Abrupt changes to coronavirus quarantine policies in Europe will have a "rollercoaster effect" on airlines and the wider economic recovery, according to the chief executive officer of the low cost carrier Wizz Air.
The U.K. government surprised many British tourists over the weekend by announcing a sudden change to its quarantine policy. Those arriving in England from Spain from Sunday onward will be required to self-isolate for 14 days.
The U.K. argued that a recent increase in the number of Covid-19 infections in Spain had prompted the decision. The Spanish government condemned the change in policy arguing that the country was safe to tourists despite some regional outbreaks.
"We used to be debating the recovery of the pandemic is 'V' shape or 'U' shape… I think we should expect a rollercoaster effect," Jozsef Varadi, CEO of Wizz Air, told CNBC's "Squawk Box Europe" on Wednesday.
"Spain will improve again but some other markets might come under scrutiny," he added, explaining that airlines will simply have to cope with the uncertainty.
Investors have expressed some concerns this week over the growing number of Covid-19 cases in different regions within Europe. Alongside Spain, Luxembourg, Romania and Bulgaria are some of the European nations seeing a spike in cases.
U.K. Prime Minister Boris Johnson said this week that "amongst some of our European friends, I am afraid you are starting to see in some places the signs of a second wave of the pandemic."
The U.K. is second only to Russia for the highest number of reported coronavirus cases in Europe.
Quim Torra, president of Catalonia, one of the Spanish regions where infections have grown in recent days, told CNBC on Wednesday that the area is still safe for international visitors.
"The world is living in a very complicated situation and in every country, there are clusters or outbreaks," he told CNBC's "Squawk Box Europe."
"In Catalonia, there are only three outbreaks… the rest of Catalonia, Costa Brava, Costa Dourada, the interior of Catalonia, the Pyrenees, are free of virus."
Spanish authorities believe that young people have contributed to the scale of the recent outbreaks.
In this context, the Catalonia region has forbidden gatherings of more than 10 people and imposed restrictions on drinking alcohol in public spaces.
Torra said they are appealing to young people "to be responsible now much more than in the first wave."