Christmas illuminations reading "Merry Christmas" are pictured on an empty street, during a night-time curfew set as part of a state of emergency in an effort to control the outbreak of the coronavirus disease (COVID-19), in Barcelona, Spain December 1, 2020. REUTERS/Nacho Doce

A deliveryman for Glovo rides his bicycle next to Christmas illuminations on an empty street, during a night-time curfew set as part of a state of emergency in an effort to control the outbreak of the coronavirus disease (COVID-19), in Barcelona, Spain December 1, 2020. REUTERS/Nacho Doce

A woman sleeps on an empty street, during a night-time curfew set as part of a state of emergency in an effort to control the outbreak of the coronavirus disease (COVID-19), in Barcelona, Spain December 2, 2020. REUTERS/Nacho Doce

A man carries a bed base as he walks on an empty street, during a night-time curfew set as part of a state of emergency in an effort to control the outbreak of the coronavirus disease (COVID-19), in Barcelona, Spain December 1, 2020. REUTERS/Nacho Doce

A man stands in front of a waste basket on an empty street, during a night-time curfew set as part of a state of emergency in an effort to control the outbreak of the coronavirus disease (COVID-19), in Barcelona, Spain December 1, 2020. REUTERS/Nacho Doce

Travelers take to the roads ahead of Thanksgiving holiday, as state and federal officials pleaded with Americans to stay at home and redouble efforts to curtail the coronavirus disease (COVID-19) pandemic, in Chicago, Illinois, U.S. November 24, 2020. REUTERS/Kamil Krzaczynski

A woman wearing a protective face mask walks at the underground Al Shohadaa "Martyrs" metro station while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany

A man wearing a protective face mask walks at the underground Al Shohadaa "Martyrs" metro station while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany

Police officer wearing a protective face mask checks passengers inside a train at the the underground Al Shohadaa "Martyrs" metro station while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany

People wearing protective face masks stand inside a train at the underground Al Shohadaa "Martyrs" metro station while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany

Women wearing protective face masks are seen inside a train at the underground Al Shohadaa "Martyrs" metro station while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany

Police members check on passengers wearing protective face mask inside the underground Al Shohadaa "Martyrs" metro while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. REUTERS/Mohamed Abd El Ghany

Men wearing protective face masks wait at the underground Al Shohadaa "Martyrs" metro station while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. REUTERS/Mohamed Abd El Ghany

A woman wearing a protective face mask is seen inside the underground Al Shohadaa "Martyrs" metro while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. REUTERS/Mohamed Abd El Ghany

Women wearing protective face masks walk at the underground Al Shohadaa "Martyrs" metro station while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. REUTERS/Mohamed Abd El Ghany

Men wearing protective face masks walk at the underground Al Shohadaa "Martyrs" metro station while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. REUTERS/Mohamed Abd El Ghany

Men wearing protective face masks are seen inside the underground Al Shohadaa "Martyrs" metro while Egypt ramps up its efforts to slow down the spread of the coronavirus disease (COVID-19) in Cairo, Egypt November 21, 2020. REUTERS/Mohamed Abd El Ghany

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau arrives to a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau attends a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

Canada's Prime Minister Justin Trudeau arrives to a news conference at Rideau Cottage, as efforts continue to help slow the spread of the coronavirus disease (COVID-19), in Ottawa, Ontario, Canada November 20, 2020. REUTERS/Blair Gable

U.S. Army Gen. Gustave Perna, who co-leads the Trump administration effort dubbed "Operation Warp Speed" to find a vaccine for the coronavirus disease (COVID-19), and Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, listen during a briefing by the White House coronavirus task force in the Brady press briefing room at the White House in Washington, U.S., November 19, 2020. REUTERS/Leah Millis

A man receives medical treatment by doctor Anna Dalmau, 29, at an outpatient center, after Catalonia's government imposed new restrictions in an effort to control the spread of the coronavirus disease (COVID-19), in Barcelona, Spain November 17, 2020. Picture taken November 17, 2020. REUTERS/Nacho Doce

Doctor Anna Dalmau, 29, poses in the corridor of an outpatient center, after Catalonia's government imposed new restrictions in an effort to control the spread of the coronavirus disease (COVID-19), in Barcelona, Spain, November 17, 2020. Picture taken November 17, 2020. REUTERS/Nacho Doce

A man receives medical treatment by doctor Anna Dalmau, 29, at an outpatient center, after Catalonia's government imposed new restrictions in an effort to control the spread of the coronavirus disease (COVID-19), in Barcelona, Spain November 17, 2020. Picture taken November 17, 2020. REUTERS/Nacho Doce

People gather in front of Macba (Barcelona Museum of Contemporary Art ), after Catalonia's government imposed new restrictions in an effort to control the spread of the coronavirus disease (COVID-19), in Barcelona, Spain November 18, 2020. REUTERS/Nacho Doce

Police officers speak to people in front of Macba (Barcelona Museum of Contemporary Art ), after Catalonia's government imposed new restrictions in an effort to control the spread of the coronavirus disease (COVID-19), in Barcelona, Spain November 18, 2020. REUTERS/Nacho Doce

A U.S. Secret Service agent wearing a protective face mask stands at his post in the Rose Garden, in front of a line of White House staff members, as President Donald Trump delivers an update on the so-called "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump smiles as he delivers an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in an address from the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

A U.S. Secret Service agent wearing a protective face mask stands at her post on the West Wing colonnade outside the Oval Office waiting for the president to walk out to the Rose Garden to deliver an update on the so-called "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump sits at his desk in the Oval Office after returning at the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, held in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump stands by his desk in the Oval Office after returning at the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump is accompanied by Vice President Mike Pence as he delivers an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in an address from the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump is accompanied by Vice President Mike Pence as he delivers an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in an address from the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump is accompanied by Vice President Mike Pence as he delivers an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in an address from the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump sits at his desk in the Oval Office after returning from the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, that was held in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump delivers an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in an address from the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump returns to the Oval Office with Vice President Mike Pence after the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump returns to the Oval Office with Vice President Mike Pence after the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump returns to the Oval Office after the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump delivers an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in an address from the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump sits at his desk in the Oval Office after returning from the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump sits in the Oval Office before delivering an update about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria TPX IMAGES OF THE DAY

U.S. President Donald Trump stands by his desk in the Oval Office after returning at the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump stands by his desk in the Oval Office after returning at the conclusion of an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump departs after delivering an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, as Vice President Mike Pence stands by the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump departs after delivering an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump listens to Vice President Mike Pence speak during an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump listens to Vice President Mike Pence speak during an event about the "Operation Warp Speed" program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in the Rose Garden of the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria

U.S. President Donald Trump delivers an update on the so-called Operation Warp Speed program, the joint Defense Department and HHS initiative that has struck deals with several drugmakers in an effort to help speed up the search for effective treatments for the ongoing coronavirus disease (COVID-19) pandemic, in an address from the Rose Garden at the White House in Washington, U.S., November 13, 2020. REUTERS/Carlos Barria TPX IMAGES OF THE DAY