Performers engage with travellers as they queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

Performers engage with travellers as they queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls TPX IMAGES OF THE DAY 

A performer juggles as he engages with travellers while they queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

International travellers arrive from the Dominican Republic, as the U.S. reopens air and land borders to vaccinated travellers for the first time since coronavirus disease (COVID-19) restrictions were imposed, at Logan International Airport in Boston, Massachusetts, U.S., November 8, 2021. REUTERS/Brian Snyder 

A traveller arrives at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

People arrive to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

A woman poses for a photograph before she checks into a flight at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

People queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

People queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

People queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

People queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

People queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

A performer dressed as Elvis Presley engages with travellers as they queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

Performers engage with travellers as they queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

Performers engage with travellers as they queue to check into Virgin Atlantic and Delta Air Lines flights at Heathrow Airport Terminal 3, following the lifting of restrictions on the entry of non-U.S. citizens to the United States imposed to curb the spread of the coronavirus disease (COVID-19), in London, Britain, November 8, 2021. REUTERS/Henry Nicholls 

A man arrives at terminal 5 of Heathrow International airport following the lifting of restrictions on the entry of non-U.S. citizens imposed to help curb the spread of the coronavirus disease (COVID-19), in London, Britain November 8, 2021. REUTERS/Carlos Barria TPX IMAGES OF THE DAY 

A screen showing American Airlines flight 101 between London and New York is seen at Heathrow International airport, following the lifting of restrictions on the entry of non-U.S. citizens imposed to help curb the spread of the coronavirus disease (COVID-19), in London, Britain November 8, 2021. REUTERS/Carlos Barria 

Passengers wait to check-in on the American Airlines flight 101 between London and New York following the lifting of restrictions on the entry of non-U.S. citizens imposed to help curb the spread of the coronavirus disease (COVID-19), at Heathrow International airport in London, Britain November 8, 2021. REUTERS/Carlos Barria