U.S. President Joe Biden displays his face mask as he speaks during an event to commemorate the 50 millionth coronavirus disease (COVID-19) vaccination in the South Court Auditorium at the White House in Washington, U.S., February 25, 2021. REUTERS/Jonathan Ernst

U.S. President Joe Biden removes his face mask to speak as he commemorates the 50 millionth coronavirus disease (COVID-19) vaccination in the South Court Auditorium at the White House in Washington, U.S., February 25, 2021. REUTERS/Jonathan Ernst

U.S. President Joe Biden displays his face mask as he speaks during an event to commemorate the 50 millionth coronavirus disease (COVID-19) vaccination in the South Court Auditorium at the White House in Washington, U.S., February 25, 2021. REUTERS/Jonathan Ernst TPX IMAGES OF THE DAY

New US Ambassador to the United Nations, Linda Thomas-Greenfield removes her face mask to speak after meeting with UN Secretary-General Antonio Guterres at the United Nations in New York City, U.S. February 25, 2021. Angela Weiss/Pool via REUTERS

New US Ambassador to the United Nations, Linda Thomas-Greenfield removes her face mask to speak after meeting with UN Secretary-General Antonio Guterres at the United Nations in New York City, U.S. February 25, 2021. Angela Weiss/Pool via REUTERS

U.S. President Joe Biden removes his face mask to speak as he commemorates the 50 millionth coronavirus disease (COVID-19) vaccination in the South Court Auditorium at the White House in Washington, U.S., February 25, 2021. REUTERS/Jonathan Ernst

French President Emmanuel Macron takes off his face mask as he arrives to deliver a press conference after a European Council summit held over video-conference, in Paris, France February 25, 2021. Thomas Coex/Pool via REUTERS

German Chancellor Angela Merkel takes off the face mask before she addresses a press conference following the EU leaders' videoconference in Berlin, Germany February 25, 2021. John MacDougall/Pool via REUTERS

Soccer Football - Europa League - Round of 32 Second Leg - Manchester United v Real Sociedad - Old Trafford, Manchester, Britain - February 25, 2021 Real Sociedad coach Imanol Alguacil wearing a protective face mask before the match REUTERS/Phil Noble

Soccer Football - Europa League - Round of 32 Second Leg - Manchester United v Real Sociedad - Old Trafford, Manchester, Britain - February 25, 2021 Manchester United manager Ole Gunnar Solskjaer wearing a protective face mask before the match REUTERS/Phil Noble

Soccer Football - Europa League - Round of 32 Second Leg - Manchester United v Real Sociedad - Old Trafford, Manchester, Britain - February 25, 2021 Real Sociedad's Nacho Monreal and teammates wearing protective face masks before the match REUTERS/Phil Noble

Soccer Football - Europa League - Round of 32 Second Leg - Arsenal v Benfica - Karaiskakis Stadium, Piraeus, Greece - February 25, 2021 Benfica substitutes wearing protective face masks REUTERS/Alkis Konstantinidis

Soccer Football - Europa League - Round of 32 Second Leg - Ajax Amsterdam v Lille - Johan Cruijff Arena, Amsterdam, Netherlands - February 25, 2021 A member of staff wearing a protective face mask before the match REUTERS/Eva Plevier

French Prime Minister Jean Castex touches his protective face mask during a press conference on the government's current strategy for the ongoing coronavirus disease (COVID-19) pandemic in Paris, France February 25, 2021. Stephane De Sakutin/Pool via REUTERS

French Prime Minister Jean Castex touches his protective face mask during a press conference on the government's current strategy for the ongoing coronavirus disease (COVID-19) pandemic in Paris, France February 25, 2021. Stephane De Sakutin/Pool via REUTERS

U.S. Senate Health, Education, Labor, and Pensions Committee Ranking Member Richard Burr (R-NC) adjusts his face mask during a Senate Health, Education, Labor, and Pensions Committee hearing on pending public health service nominations on Capitol Hill in Washington, U.S., February 24, 2021. REUTERS/Tom Brenner/Pool

Rachel Levine, nominated to be an assistant secretary at the Department of Health and Human Services, holds her face mask as she testifies during a Senate Health, Education, Labor, and Pensions Committee hearing on Capitol Hill in Washington, U.S., February 24, 2021. REUTERS/Tom Brenner/Pool

Women wearing protective face masks shop at a vegetable market amid the coronavirus disease (COVID-19) pandemic in Cairo, Egypt February 25, 2021. REUTERS/Mohamed Abd El Ghany

A worker wearing a protective face mask carries dough to be placed in an oven at a bakery amid the coronavirus disease (COVID-19) pandemic in Cairo, Egypt February 25, 2021. REUTERS/Mohamed Abd El Ghany

A teddy bear, wearing a protective face mask, is seen in a pharmacy in Gouzeaucourt amid the coronavirus disease (COVID-19) outbreak in France, February 25, 2021. REUTERS/Pascal Rossignol

A visitor wears a protective face mask in the Rescue Shelter, which was opened by the Orthodox charity organisation Miloserdie to provide services to the homeless, in Moscow, Russia February 16, 2021. Picture taken February 16, 2021. REUTERS/Evgenia Novozhenina

Greek university students wearing protective face masks take part in a demonstration against government plans to set up a university police, amid the coronavirus disease (COVID-19) pandemic, in front of the Greek parliament in Athens, Greece, February 25, 2021. REUTERS/Louiza Vradi

Greek university students wearing protective face masks take part in a demonstration against government plans to set up a university police, amid the coronavirus disease (COVID-19) pandemic, in Athens, Greece, February 25, 2021. REUTERS/Louiza Vradi

Greek university students wearing protective face masks take part in a demonstration against government plans to set up a university police, amid the coronavirus disease (COVID-19) pandemic, in Athens, Greece, February 25, 2021. REUTERS/Louiza Vradi

A doctor, wearing a protective face mask, prepares a dose of the Oxford-AstraZeneca COVID-19 vaccine in his consulting room at the doctor's office in Gouzeaucourt as part of the coronavirus disease (COVID-19) vaccination campaign in France, February 24, 2021. Picture taken on February 24, 2021. REUTERS/Pascal Rossignol

Greek university students wearing protective face masks hold placards during a demonstration against government plans to set up a university police, amid the coronavirus disease (COVID-19) pandemic, in Athens, Greece, February 25, 2021. REUTERS/Louiza Vradi

Greek university students wearing protective face masks hold placards during a demonstration against government plans to set up a university police, amid the coronavirus disease (COVID-19) pandemic, in Athens, Greece, February 25, 2021. REUTERS/Louiza Vradi

Local officials wearing face masks and face shields as protection against the coronavirus disease (COVID-19) stand near a community quarantine checkpoint in a village under local lockdown, in Pasay, Metro Manila, Philippines, February 25, 2021. REUTERS/Lisa Marie David

A woman wearing a face mask and a face shield as protection against the coronavirus disease (COVID-19) checks her temperature at a community quarantine checkpoint, in Pasay, Metro Manila, Philippines, February 25, 2021. REUTERS/Lisa Marie David

A man wearing a face mask and a face shield as protection against the coronavirus disease (COVID-19) enters a disinfection booth at a community quarantine checkpoint, in Pasay, Metro Manila, Philippines, February 25, 2021. REUTERS/Lisa Marie David

A local official wears a face mask and a face shield as protection against the coronavirus disease (COVID-19) near a community quarantine checkpoint in a village under local lockdown, in Pasay, Metro Manila, Philippines, February 25, 2021. REUTERS/Lisa Marie David

A man wears a face mask and a face shield as protection against the coronavirus disease (COVID-19) near a community quarantine checkpoint in a village under local lockdown, in Pasay, Metro Manila, Philippines, February 25, 2021. REUTERS/Lisa Marie David

Fan wearing protective face masks and caps featuring India's Ravichandran Ashwin, Washington Sundar, Jasprit Bumrah, Ajinkya Rahane, captain Virat Kohli, Axar Patel, Rohit Sharma and Cheteshwar Pujara pose as they wait to enter the newly named Narendra Modi Stadium, previously known as Motera Stadium, before the start of the second day's play in the third test match between India and England, amidst the spread of the coronavirus disease (COVID-19), in Ahmedabad, India, February 25, 2021. REUTERS/Amit Dave

A fan wearing a protective face mask and a cap featuring India's cricket team captain Virat Kohli gestures as he waits to enter the newly named Narendra Modi Stadium, previously known as Motera Stadium, before the start of the second day's play in the third test match between India and England, amidst the spread of the coronavirus disease (COVID-19), in Ahmedabad, India, February 25, 2021. REUTERS/Amit Dave

Greek Prime Minister Kyriakos Mitsotakis wears a protective face mask during a parliamentary session on revelations of abuse in arts and sports, in Athens, Greece, February 25, 2021. REUTERS/Alkis Konstantinidis

President of the Tokyo 2020 Olympics Organising Committee Seiko Hashimoto removes her face mask during the opening remarks session of the press briefing on operation and media coverage of Tokyo 2020 Olympic Torch Relay in Tokyo, Japan February 25, 2021. Behrouz Mehri/Pool via REUTERS

Xavier Becerra puts on a face mask upon the conclusion of the Senate Finance Committee hearing on his nomination to be secretary of Health and Human Services (HHS), on Capitol Hill in Washington, DC, U.S., February 24, 2021. Michael Reynolds/Pool via REUTERS

Xavier Becerra puts on a face mask upon the conclusion of the Senate Finance Committee hearing on his nomination to be secretary of Health and Human Services (HHS), on Capitol Hill in Washington, DC, U.S., February 24, 2021. Michael Reynolds/Pool via REUTERS

U.S. State Department Spokesman Ned Price faces reporters during a news briefing at the State Department in Washington, U.S., February 24, 2021. REUTERS/Carlos Barria/Pool

Visitors wearing face masks queue to enter the ancient Teotihuacan pyramids during the gradual reopening to the public, as the coronavirus disease (COVID-19) outbreak continues, in San Juan Teotihuacan, Mexico February 24, 2021. REUTERS/Toya Sarno Jordan

U.S. State Department Spokesman Ned Price faces reporters during a news briefing at the State Department in Washington, U.S., February 24, 2021. REUTERS/Carlos Barria/Pool

U.S. State Department Spokesman Ned Price faces reporters during a news briefing at the State Department in Washington, U.S., February 24, 2021. REUTERS/Carlos Barria/Pool

A man wearing a protective face mask walks past a painted wall, amid the coronavirus disease (COVID-19) outbreak in Dublin, Ireland February 24, 2021. REUTERS/Clodagh Kilcoyne TPX IMAGES OF THE DAY

United States Postal Service Postmaster General Louis DeJoy adjusts his face mask during a House Oversight and Reform Committee hearing on "Legislative Proposals to Put the US Postal Service on Sustainable Financial Footing" on Capitol Hill in Washington, DC, U.S., February 24, 2021. Graeme Jennings/Pool via REUTERS

United States Postal Service Postmaster General Louis DeJoy adjusts his face mask during a House Oversight and Reform Committee hearing on "Legislative Proposals to Put the US Postal Service on Sustainable Financial Footing" on Capitol Hill in Washington, DC, U.S., February 24, 2021. Graeme Jennings/Pool via REUTERS

Venezuela's Foreign Minister Jorge Arreaza adjusts his protective face mask at the Foreign Ministry headquarters in Caracas, Venezuela February 24, 2021. REUTERS/Manaure Quintero

People wearing protective face masks walk near the beach in Dunkirk as the government eyes new measures to limit the spread of COVID-19 in the region, France, February 24, 2021. REUTERS/ Pascal Rossignol

People wearing protective face masks walk near the beach in Dunkirk as the government eyes new measures to limit the spread of COVID-19 in the region, France, February 24, 2021. REUTERS/ Pascal Rossignol

People wearing protective face masks walk near the beach in Dunkirk as the government eyes new measures to limit the spread of COVID-19 in the region, France, February 24, 2021. REUTERS/ Pascal Rossignol

People wearing protective face masks walk near the beach in Dunkirk as the government eyes new measures to limit the spread of COVID-19 in the region, France, February 24, 2021. REUTERS/ Pascal Rossignol

French Government's spokesperson Gabriel Attal, wearing a protective face mask, leaves following the weekly cabinet meeting at the Elysee Palace in Paris, France, February 24, 2021. REUTERS/Sarah Meyssonnier

German Health Minister Jens Spahn adjusts his face mask during a plenum session on the spread of the coronavirus disease (COVID-19) at the lower house of parliament, the Bundestag, in Berlin, Germany, February 24, 2021. REUTERS/Annegret Hilse

People wear face masks as they walk past a closed retail unit amid the outbreak of the coronavirus disease (COVID-19) in Warrington, Britain, February 24, 2021. REUTERS/Phil Noble

A woman wears a face mask as she walks past a closed retail unit amid the outbreak of the coronavirus disease (COVID-19) in Warrington, Britain, February 24, 2021. REUTERS/Phil Noble

German Health Minister Jens Spahn adjusts his face mask during a plenum session on the spread of the coronavirus disease (COVID-19) at the lower house of parliament, the Bundestag, in Berlin, Germany, February 24, 2021. REUTERS/Annegret Hilse

European Commissioner for European Green Deal Frans Timmermans puts on his protective face mask after addressing a media conference on a new EU strategy on adaptation to climate change at EU headquarters in Brussels, Belgium February 24, 2021. Olivier Matthys/Pool via REUTERS

Badre Jaafar, director of SERMP, a Casablanca-based company that supplies parts to French aircraft engine maker Safran, shows a face masks-making machine to Karim Cheikh, head of Morocco's aerospace suppliers association, in Casablanca, Morocco February 23, 2021. Picture taken February 23, 2021. REUTERS/Abdelhak Balhaki

Kajima employee Gunasekar Udayakumar uses the Nervotec app to scan his face and check his vital signs as part of a daily checkup for employees at a construction site in central Singapore, February 19, 2021. Picture taken February 19, 2021. REUTERS/Joseph Campbell

Kajima employee Gunasekar Udayakumar uses the Nervotec app to scan his face and check his vital signs as part of a daily checkup for employees at a construction site in central Singapore, February 19, 2021. Picture taken February 19, 2021. REUTERS/Joseph Campbell

U.S. President Joe Biden and Canada's Prime Minister Justin Trudeau, holding his face mask, appearing via video conference call, give closing remarks at the end of their virtual bilateral meeting from the White House in Washington, U.S. February 23, 2021. REUTERS/Jonathan Ernst