A lab technician performs a step in the testing procedure, which according to local media was ordered by Mexican health authorities, to investigate if a new strain of the coronavirus disease (COVID-19) detected in the state of Jalisco could be a Mexican variant of SARS-CoV-2, in Guadalajara, Mexico February 3, 2021. REUTERS/Fernando Carranza

A lab technician performs a step in the testing procedure, which according to local media was ordered by Mexican health authorities, to investigate if a new strain of the coronavirus disease (COVID-19) detected in the state of Jalisco could be a Mexican variant of SARS-CoV-2, in Guadalajara, Mexico February 3, 2021. REUTERS/Fernando Carranza

A lab technician performs a step in the testing procedure, which according to local media was ordered by Mexican health authorities, to investigate if a new strain of the coronavirus disease (COVID-19) detected in the state of Jalisco could be a Mexican variant of SARS-CoV-2, in Guadalajara, Mexico February 3, 2021. REUTERS/Fernando Carranza

A lab technician working on a testing procedure, which according to local media was ordered by Mexican health authorities, to investigate if a new strain of the coronavirus disease (COVID-19) detected in the state of Jalisco could be a Mexican variant of SARS-CoV-2, is seen in a restricted area of the facility in Guadalajara, Mexico February 3, 2021. REUTERS/Fernando Carranza

A lab technician performs a step in the testing procedure, which according to local media was ordered by Mexican health authorities, to investigate if a new strain of the coronavirus disease (COVID-19) detected in the state of Jalisco could be a Mexican variant of SARS-CoV-2, in Guadalajara, Mexico February 3, 2021. REUTERS/Fernando Carranza

A lab technician performs a step in the testing procedure, which according to local media was ordered by Mexican health authorities, to investigate if a new strain of the coronavirus disease (COVID-19) detected in the state of Jalisco could be a Mexican variant of SARS-CoV-2, in Guadalajara, Mexico February 3, 2021. REUTERS/Fernando Carranza

A lab technician performs a step in the testing procedure, which according to local media was ordered by Mexican health authorities, to investigate if a new strain of the coronavirus disease (COVID-19) detected in the state of Jalisco could be a Mexican variant of SARS-CoV-2, in Guadalajara, Mexico February 3, 2021. REUTERS/Fernando Carranza

A lab technician performs a step in the testing procedure, which according to local media was ordered by Mexican health authorities, to investigate if a new strain of the coronavirus disease (COVID-19) detected in the state of Jalisco could be a Mexican variant of SARS-CoV-2, in Guadalajara, Mexico February 3, 2021. REUTERS/Fernando Carranza

A scientist at Bioscientia laboratories prepares a tray with positive coronavirus samples to get them sequenced and analysed for the mutant strains, as the spread of COVID-19 continues, at the Bioscientia headquarters in Ingelheim, Germany, January 27, 2021. REUTERS/Kai Pfaffenbach

A scientist at Bioscientia laboratories prepares a tray with positive coronavirus samples to get them sequenced and analysed for the mutant strains, as the spread of COVID-19 continues, at the Bioscientia headquarters in Ingelheim, Germany, January 27, 2021. REUTERS/Kai Pfaffenbach

A scientist at Bioscientia laboratories prepares a tray with positive coronavirus samples to get them sequenced and analysed for the mutant strains, as the spread of COVID-19 continues, at the Bioscientia headquarters in Ingelheim, Germany, January 27, 2021. REUTERS/Kai Pfaffenbach

A scientist at Bioscientia laboratories prepares a tray with positive coronavirus samples to get them sequenced and analysed for the mutant strains, as the spread of COVID-19 continues, at the Bioscientia headquarters in Ingelheim, Germany, January 27, 2021. REUTERS/Kai Pfaffenbach

A scientist at Bioscientia laboratories prepares a tray with positive coronavirus samples to get them sequenced and analysed for the mutant strains, as the spread of COVID-19 continues, at the Bioscientia headquarters in Ingelheim, Germany, January 27, 2021. REUTERS/Kai Pfaffenbach

A scientist at Bioscientia laboratories prepares a tray with positive coronavirus samples to get them sequenced and analysed for the mutant strains, as the spread of COVID-19 continues, at the Bioscientia headquarters in Ingelheim, Germany, January 27, 2021, REUTERS/Kai Pfaffenbach

Passengers walk inside a terminal at Ben Gurion international airport before Israel bans international flights, taking effect from Monday midnight until the end of January, in order to stop the spread of the coronavirus disease (COVID-19) and new coronavirus strains, in Lod near Tel Aviv, Israel January 25, 2021. REUTERS/Ronen Zvulun

A passenger looks at the information monitor inside a terminal at Ben Gurion international airport before Israel bans international flights, taking effect from Monday midnight until the end of January, in order to stop the spread of the coronavirus disease (COVID-19) and new coronavirus strains, in Lod near Tel Aviv, Israel January 25, 2021. REUTERS/Ronen Zvulun

A passenger walks inside a terminal at Ben Gurion international airport before Israel bans international flights, taking effect from Monday midnight until the end of January, in order to stop the spread of the coronavirus disease (COVID-19) and new coronavirus strains, in Lod near Tel Aviv, Israel January 25, 2021. REUTERS/Ronen Zvulun

Passengers walk inside a terminal at Ben Gurion international airport before Israel bans international flights, taking effect from Monday midnight until the end of January, in order to stop the spread of the coronavirus disease (COVID-19) and new coronavirus strains, in Lod near Tel Aviv, Israel January 25, 2021. REUTERS/Ronen Zvulun

A passenger arrives to a terminal at Ben Gurion international airport before Israel bans international flights, taking effect from Monday midnight until the end of January, in order to stop the spread of the coronavirus disease (COVID-19) and new coronavirus strains, in Lod near Tel Aviv, Israel January 25, 2021. REUTERS/Ronen Zvulun

A passenger arrives to a terminal at Ben Gurion international airport before Israel bans international flights, taking effect from Monday midnight until the end of January, in order to stop the spread of the coronavirus disease (COVID-19) and new coronavirus strains, in Lod near Tel Aviv, Israel January 25, 2021. REUTERS/Ronen Zvulun

The Pit Stop at the Eurotunnel, where lorries are checked before boarding the Shuttle Freight from France to Britain, is seen in Coquelles near Calais, after France barred all people coming from the United Kingdom, for 48 hours from Sunday night, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19) in France, December 22, 2020. REUTERS/Pascal Rossignol

COVID marshals walk on Eel Brook Common as EU countries impose a travel ban from the UK amid alarm about a rapidly spreading strain of coronavirus, in Fulham, London, Britain, December 22, 2020. REUTERS/Kevin Coombs

The Pit Stop at the Eurotunnel, where lorries are checked before boarding the Shuttle Freight from France to Britain, is seen in Coquelles near Calais, after France barred all people coming from the United Kingdom, for 48 hours from Sunday night, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19) in France, December 22, 2020. REUTERS/Pascal Rossignol

An empty road were trucks from Britain usually leave the Eurotunnel terminal to join the highway is seen in Coquelles near Calais, northern France, after France barred all people coming from the United Kingdom, for 48 hours from Sunday night, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19) in France, December 22, 2020. REUTERS/Pascal Rossignol

The Eurotunnel Shuttle Freight from Britain to France is seen in Coquelles near Calais, northern France, after France barred all people coming from the United Kingdom, for 48 hours from Sunday night, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19) in France, December 22, 2020. REUTERS/Pascal Rossignol

An empty Eurotunnel Shuttle Freight from Britain to France appears in Coquelles near Calais, northern France, after France barred all people coming from the United Kingdom, for 48 hours from Sunday night, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19) in France, December 22, 2020. REUTERS/Pascal Rossignol

A man walks past lorries parked on the M20 motorway after EU countries imposed a ban on travel from the UK due to a new strain of the coroanvirus spreading in Britain, near Ashford, England, December 22, 2020. REUTERS/Simon Dawson

Passengers wearing protective face masks wait to exit upon arrival at Chhatrapati Shivaji Maharaj International Airport after India cancelled all flights from the UK over fears of a new strain of the coronavirus disease (COVID-19), in Mumbai, India, December 22, 2020. REUTERS/Francis Mascarenhas

An airport official helps a passenger wearing a protective face mask upon arrival at Chhatrapati Shivaji Maharaj International Airport after India cancelled all flights from the UK over fears of a new strain of the coronavirus disease (COVID-19), in Mumbai, India, December 22, 2020. REUTERS/Francis Mascarenhas

People wearing protective face masks wait for passengers to arrive at Chhatrapati Shivaji Maharaj International Airport after India cancelled all flights from the UK over fears of a new strain of the coronavirus disease (COVID-19), in Mumbai, India, December 22, 2020. REUTERS/Francis Mascarenhas

Passengers wearing protective face masks leave upon arrival at Chhatrapati Shivaji Maharaj International Airport after India cancelled all flights from the UK over fears of a new strain of the coronavirus disease (COVID-19), in Mumbai, India, December 22, 2020. REUTERS/Francis Mascarenhas

Passengers tag their luggage before checking at the counter of British Airways, as the Mexico's government analyses to suspend flights from the U.K. due to fears about a highly infectious new coronavirus strain amid the coronavirus disease (COVID-19) outbreak, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

Passengers are seen at the counter of British Airways to check in for their flights to London, as the Mexico's government analyses to suspend flights from the U.K. due to fears about a highly infectious new coronavirus strain amid the coronavirus disease (COVID-19) outbreak, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A flight information screen displays the arrivals and delayed flights, including the one from London, as the Mexico's government analyses to suspend flights from the U.K. due to fears about a highly infectious new coronavirus strain amid the coronavirus disease (COVID-19) outbreak, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A sign is pictured as passengers check-in their flights to London at the counter of British Airways, as the Mexico's government analyses to suspend flights from the U.K. due to fears about a highly infectious new coronavirus strain amid coronavirus disease (COVID-19) outbreak, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A police officer assists a passenger arriving from London, as the Mexico's government analyses to suspend flights from the U.K. due to fears about a highly infectious new coronavirus strain amid coronavirus disease (COVID-19) outbreak, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

Passengers are pictured after arriving from London, as the Mexico's government analyses to suspend flights from the U.K. due to fears about a highly infectious new coronavirus strain amid coronavirus disease (COVID-19) outbreak, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A flight information screen displays the arrivals and delayed flights, including the one from London, as the Mexico's government analyses to suspend flights from the U.K. due to fears about a highly infectious new coronavirus strain amid the coronavirus disease (COVID-19) outbreak, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

An employee of El Dorado International Airport wearing a face screen and mask gives directions to a female passenger, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

Passengers wearing face masks line up to check in at El Dorado airport, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

The exterior of the El Dorado international airport is seen, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

A passenger wearing face masks takes his suitcase to check in at El Dorado airport, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

A passenger wearing face masks takes her suitcase to check in at El Dorado airport, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

Passengers wearing face masks line up to check in at El Dorado airport, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

A face mask dispensing machine is seen outside El Dorado International Airport, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

Passengers wearing face masks line up to check in at El Dorado airport, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

A passenger wearing face masks takes his suitcase to check in at El Dorado airport, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

Passengers wearing face masks line up to check in at El Dorado airport, after the Colombian government decreed restrictions on flights from the United Kingdom, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19), in Bogota, Colombia December 21, 2020. REUTERS/Luisa Gonzalez

A passenger is assisted by an airline employee whilst arriving to the counter of British Airways, as the Mexico's government analyses to suspend flights from the U.K. due to fears about a highly infectious new coronavirus disease (COVID-19) strain, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A sign is pictured at a counter of British Airways, as Mexico's government analyses whether to suspend flights from the UK due to fears about a highly infectious new coronavirus strain, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A view shows the counters of British Airways, as Mexico's government analyses whether to suspend flights from the UK due to fears about a highly infectious new coronavirus strain, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A sign is pictured at the counters of British Airways, as Mexico's government analyses whether to suspend flights from the UK due to fears about a highly infectious new coronavirus strain, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A passenger speaks on the phone after asking for information at the counter of British Airways, as Mexico's government analyses whether to suspend flights from the UK due to fears about a highly infectious new coronavirus strain, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A passenger checks his documentation near to a counter of British Airways, as Mexico's government analyses whether to suspend flights from the UK due to fears about a highly infectious new coronavirus strain, at the Benito Juarez International Airport, in Mexico City, Mexico December 21, 2020. REUTERS/Luis Cortes

A truck drives on the deserted Eurotunnel road access in Coquelles near Calais, northern France, after France barred all people coming from the United Kingdom, for 48 hours from Sunday night, over fears of a new strain of the coronavirus, amid the spread of the coronavirus disease (COVID-19) in France, December 21, 2020. REUTERS/Caroline Pailliez

Passengers cross the tarmac of the Gibraltar International Airport as they walk to the Spanish border, after the Spanish government announced it will ban all travelers from Britain, except Spanish nationals and residents, from entering the country from Tuesday amid concerns over a rapidly spreading new strain of the coronavirus, in Gibraltar December 21, 2020. REUTERS/Jon Nazca

Passengers walk out of the Gibraltar International Airport after the Spanish government announced it will ban all travelers from Britain, except Spanish nationals and residents, from entering the country from Tuesday amid concerns over a rapidly spreading new strain of the coronavirus, in Gibraltar December 21, 2020. REUTERS/Jon Nazca

An aircraft of the British Airlines takes off at the Gibraltar International Airport, after the Spanish government announced it will ban all travelers from Britain, except Spanish nationals and residents, from entering the country from Tuesday amid concerns over a rapidly spreading new strain of the coronavirus, in Gibraltar December 21, 2020. REUTERS/Jon Nazca

Passengers pull their suitcases after arriving at the Gibraltar International Airport, after the Spanish government announced it will ban all travelers from Britain, except Spanish nationals and residents, from entering the country from Tuesday amid concerns over a rapidly spreading new strain of the coronavirus, in Gibraltar December 21, 2020. REUTERS/Jon Nazca