Lothar Wieler, the head of Germany's Robert Koch Institute (RKI) for disease control, and German Health Minister Spahn attend a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

Director of the Institute for Virology at the Charite Christian Drosten arrives for a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

Director of the Institute for Virology at the Charite Christian Drosten and German Health Minister Jens Spahn stand next to media ahead of a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

A supporter of India's main opposition Congress party hits a poster of Arnab Goswami, one of India's top TV news anchors, during a protest in Mumbai, India, January 22, 2021. REUTERS/Francis Mascarenhas

President of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI) Gernot Marx attends a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

Lothar Wieler, the head of Germany's Robert Koch Institute (RKI) for disease control, speaks during a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

The logo of Tokyo 2020 Olympic Games that have been postponed to 2021 due to the coronavirus disease (COVID-19) outbreak, is seen through signboards, at Tokyo Metropolitan Government Office building in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

The logo of Tokyo 2020 Olympic Games that have been postponed to 2021 due to the coronavirus disease (COVID-19) outbreak, is seen through signboards, at Tokyo Metropolitan Government Office building in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

Japanese Prime Minister Yoshihide Suga attends a meeting of the coronavirus disease (COVID-19) infection control headquarters at the prime minister's office in Tokyo, Japan January 22, 2021. Kazuhiro Nogi/Pool via REUTERS

The logo of Tokyo 2020 Olympic Games that have been postponed to 2021 due to the coronavirus disease (COVID-19) outbreak, is displayed at Tokyo Metropolitan Government Office building in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

Japanese Prime Minister Yoshihide Suga speaks during a meeting of the coronavirus disease (COVID-19) infection control headquarters at the prime minister's office in Tokyo, Japan January 22, 2021. Kazuhiro Nogi/Pool via REUTERS

Japanese Prime Minister Yoshihide Suga speaks during a meeting of the coronavirus disease (COVID-19) infection control headquarters at the prime minister's office in Tokyo, Japan January 22, 2021. Kazuhiro Nogi/Pool via REUTERS

The logo of Tokyo 2020 Olympic Games that have been postponed to 2021 due to the coronavirus disease (COVID-19) outbreak, is seen through a traffic sign at Tokyo Metropolitan Government Office building in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

Director of the Institute for Virology at the Charite Christian Drosten removes his protective face mask before the start of a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

Director of the Institute for Virology at the Charite Christian Drosten attends a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

Director of the Institute for Virology at the Charite Christian Drosten attends a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

Director of the Institute for Virology at the Charite Christian Drosten speaks during a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

Director of the Institute for Virology at the Charite Christian Drosten speaks during a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

German Health Minister Jens Spahn speaks during a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

German Health Minister Jens Spahn attends a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

German Health Minister Jens Spahn and Director of the Institute for Virology at the Charite Christian Drosten arrive for a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

German Health Minister Jens Spahn and Director of the Institute for Virology at the Charite Christian Drosten arrive for a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

Director of the Institute for Virology at the Charite Christian Drosten attends a news conference, amid the spread of the coronavirus disease (COVID-19), in Berlin, Germany, January 22, 2021. REUTERS/Fabrizio Bensch/Pool

An Iraqi security force member checks a man near the damage site in the aftermath of a twin suicide bombing attack in a central market, in Baghdad, Iraq January 22, 2021. REUTERS/Khalid al-Mousily

A medical worker in a protective suit collects a swab from a woman for nucleic acid testing at a makeshift testing site following the coronavirus disease (COVID-19) outbreak in Beijing, China January 22, 2021. REUTERS/Yilei Sun

An Iraqi security force member walks near the damage site in the aftermath of a twin suicide bombing attack in a central market, in Baghdad, Iraq January 22, 2021. REUTERS/Khalid al-Mousily

A man wearing a protective face mask walks between advertisings of Tokyo 2020 Olympic Games that have been postponed to 2021 due to the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

FILE PHOTO: Dr. Rochelle Walensky, U.S. President-elect Joe Biden's appointee to run the U.S. Centers for Disease Control and Prevention (CDC), removes her mask to speak as Biden announces nominees and appointees to serve on his health and coronavirus response teams during a news conference at his transition headquarters in Wilmington, Delaware, U.S., December 8, 2020. REUTERS/Kevin Lamarque/File Photo

A man wearing a protective face mask walks past an advertising of Tokyo 2020 Olympic Games that have been postponed to 2021 due to the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

Members of Iraqi security forces check on people near the damage site in the aftermath of a twin suicide bombing attack in a central market, in Baghdad, Iraq January 22, 2021. REUTERS/Khalid al-Mousily

A man wearing a protective face mask walks past an advertising showing Tokyo 2020 Olympic Games mascot Miraitowa, amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

A man wearing a protective face mask walks past an advertising showing Tokyo 2020 Olympic Games mascot Miraitowa, amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

A passerby wearing a protective face mask walks past an advertising of Tokyo 2020 Olympic Games that have been postponed to 2021 due to the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan January 22, 2021. REUTERS/Issei Kato

Senior citizens, wearing protective face masks, wait for the opening of a coronavirus disease (COVID-19) vaccination center in Nice, France, January 22, 2021. REUTERS/Eric Gaillard

People inspect the damage site in the aftermath of a twin suicide bombing attack in a central market, in Baghdad, Iraq January 22, 2021. REUTERS/Khalid al-Mousily

Senior citizens, wearing protective face masks, wait for the opening of a coronavirus disease (COVID-19) vaccination center in Nice, France, January 22, 2021. REUTERS/Eric Gaillard

Senior citizens wait for the opening of a coronavirus disease (COVID-19) vaccination center in Nice, France, January 22, 2021. REUTERS/Eric Gaillard

A worker walks on stacks of containers at the Tanjung Priok port in Jakarta, Indonesia, January 22, 2021. REUTERS/Ajeng Dinar Ulfiana

People gather at the damaged site in the aftermath of a twin suicide bombing attack in a central market, in Baghdad, Iraq January 22, 2021. REUTERS/Khalid al-Mousily

A family member of the passenger of Sriwijaya Air flight SJ 182, which crashed into the sea, mourns while visiting the site of the crash to pay their tribute, on the deck of Indonesia's Naval ship KRI Semarang, at the sea off the Jakarta coast, Indonesia, January 22, 2021. REUTERS/Ajeng Dinar Ulfiana

People line up to get their nucleic acid test at a mass testing site following the outbreak of the coronavirus disease (COVID-19) in Beijing, China, January 22, 2021. REUTERS/Thomas Peter

People line up to get their nucleic acid test at a mass testing site following the outbreak of the coronavirus disease (COVID-19) in Beijing, China, January 22, 2021. REUTERS/Thomas Peter

People line up to get their nucleic acid test at a mass testing site following the outbreak of the coronavirus disease (COVID-19) in Beijing, China, January 22, 2021. REUTERS/Thomas Peter

People line up to get their nucleic acid test at a mass testing site following the outbreak of the coronavirus disease (COVID-19) in Beijing, China, January 22, 2021. REUTERS/Thomas Peter

A family member of the passenger of Sriwijaya Air flight SJ 182, which crashed into the sea, mourns while visiting the site of the crash to pay their tribute, on the deck of Indonesia's Naval ship KRI Semarang, at the sea off the Jakarta coast, Indonesia, January 22, 2021. REUTERS/Ajeng Dinar Ulfiana

People line up to get their nucleic acid test at a mass testing site following the outbreak of the coronavirus disease (COVID-19) in Beijing, China, January 22, 2021. REUTERS/Thomas Peter

Empty spectator seats of Ariake Urban Sports Park for the Tokyo 2020 Olympic Games are pictured amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

A woman wearing a protective mask walks past Ariake Gymnastics Centre for the Tokyo 2020 Olympic Games, amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

A woman wearing a protective mask rides a bicycle past Ariake Gymnastics Centre for the Tokyo 2020 Olympic Games, amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

Empty parking lots are seen in front of Ariake Gymnastics Centre for the Tokyo 2020 Olympic Games, amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

The giant Olympic rings are seen between rocks at a park , amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

Empty spectator seats of Ariake Urban Sports Park for the Tokyo 2020 Olympic Games, are pictured amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

People wearing protective masks, amid the coronavirus disease (COVID-19) outbreak, are seen in front of the giant Olympic rings in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

A man holding a cat in his bag visits a park where the giant Olympic rings are viewed, amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

The giant Olympic rings are seen between rocks at a park , amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

People wearing protective masks, amid the coronavirus disease (COVID-19) outbreak, are seen in front of the giant Olympic rings in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

The giant Olympic rings are seen over the sea, amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan, January 22, 2021. REUTERS/Kim Kyung-Hoon

Taiwan's Chief trade negotiator John Deng looks on as he speaks to the media in Taipei, Taiwan, January 22, 2021. REUTERS/Ann Wang

Rescuers work at the Hushan gold mine where workers were trapped underground after the Jauary 10 explosion, in Qixia, Shandong province, China January 22, 2021. REUTERS/Aly Song