Nurse Rebecca prepares a bag for infectious material as she treats patients suffering from the coronavirus disease (COVID-19) at the COVID-19 ward at a clinic in Darmstadt, Germany, May 11, 2021. REUTERS/Kai Pfaffenbach

Nurse Rebecca prepares breakfast for a patient suffering from the coronavirus disease (COVID-19) at the COVID-19 ward at a clinic in Darmstadt, Germany, May 11, 2021. REUTERS/Kai Pfaffenbach

Nurses Rebecca and Maria prepare themselves with PPE before treating patients suffering from the coronavirus disease (COVID-19) at the COVID-19 ward at a clinic in Darmstadt, Germany, May 11, 2021. REUTERS/Kai Pfaffenbach

Britain's Prince Charles, Prince of Wales, visits Smithfield Market to view the construction and preservation work being undertaken in preparation for the site to become the new home of the Museum of London, in London, Britain May 11, 2021. Arthur Edwards/Pool via REUTERS

Britain's Prince Charles, Prince of Wales, visits Smithfield Market to view the construction and preservation work being undertaken in preparation for the site to become the new home of the Museum of London, in London, Britain May 11, 2021. Arthur Edwards/Pool via REUTERS

Britain's Prince Charles, Prince of Wales, visits Smithfield Market to view the construction and preservation work being undertaken in preparation for the site to become the new home of the Museum of London, in London, Britain May 11, 2021. Arthur Edwards/Pool via REUTERS

Britain's Prince Charles, Prince of Wales, visits Smithfield Market to view the construction and preservation work being undertaken in preparation for the site to become the new home of the Museum of London, in London, Britain May 11, 2021. Arthur Edwards/Pool via REUTERS

Britain's Prince Charles, Prince of Wales, visits Smithfield Market to view the construction and preservation work being undertaken in preparation for the site to become the new home of the Museum of London, in London, Britain May 11, 2021. Arthur Edwards/Pool via REUTERS

Rochelle Walensky, Director of the US Centers for Disease Control and Prevention (CDC), prepares to testify before a Senate Health, Education, Labor and Pensions Committee hearing to discuss the on-going federal response to COVID-19, at the U.S. Capitol in Washington, D.C., U.S., May 11, 2021. Jim Lo Scalzo/Pool via REUTERS

A woman wearing a protective face mask prepares food at her stall during the coronavirus disease (COVID-19) pandemic, in Taipei, Taiwan, May 11, 2021. REUTERS/Ann Wang

Britain's Queen Elizabeth prepares for her speech in the House of Lord's Chamber during the State Opening of Parliament in London, Britain May 11, 2021. Chris Jackson/Pool via REUTERS

Britain's Queen Elizabeth prepares for her speech in the House of Lord's Chamber during the State Opening of Parliament in London, Britain May 11, 2021. Chris Jackson/Pool via REUTERS

Britain's Queen Elizabeth prepares for her speech in the House of Lord's Chamber during the State Opening of Parliament in London, Britain May 11, 2021. Chris Jackson/Pool via REUTERS

Ryo Kosone of Japan prepares for the men's Discus Throw competition during the Tokyo 2020 Paralympics athletics test event at Olympic Stadium (National Stadium) in Tokyo, Japan May 11, 2021. REUTERS/Issei Kato

People walk past shops as they prepare for the upcoming holiday of Eid al-Fitr, marking the end of Ramadan, at the old souk of Tripoli, Lebanon May 10, 2021. Picture taken May 10, 2021. REUTERS/Walid Saleh

A healthcare worker prepares to administer the coronavirus disease (COVID-19) vaccine in the remote mountain village of Ljevista, Kolasin municipality, Montenegro, May 10, 2021. REUTERS/Stevo Vasiljevic

Healthcare workers prepare to administer the coronavirus disease (COVID-19) vaccine to an elderly woman in her hut in the remote mountain village of Redice, Kolasin municipality, Montenegro, May 10, 2021. REUTERS/Stevo Vasiljevic

A healthcare worker prepares to administer the coronavirus disease (COVID-19) vaccine to an elderly man in his home in the remote mountain village of Ljevista, Kolasin municipality, Montenegro, May 10, 2021. REUTERS/Stevo Vasiljevic

A healthcare worker prepares to administer the coronavirus disease (COVID-19) vaccine to villagers in a remote ambulance in mountain village Dragovica Polje, Kolasin municipality, Montenegro, May 10, 2021. REUTERS/Stevo Vasiljevic

Andrew Yang, Democratic candidate for mayor of New York City, prepares to embrace U.S. Congresswoman Grace Meng (D-NY) after her endorsement in the Queens borough of New York, U.S., May 10, 2021. REUTERS/Shannon Stapleton REFILE - CORRECTING GRACE MENG'S TITLE

Andrew Yang, Democratic candidate for mayor of New York City, prepares to embrace New York State Congresswoman Grace Meng after her endorsement in the Queens borough of New York, U.S., May 10, 2021. REUTERS/Shannon Stapleton

United Nations High Commissioner for Refugees Filippo Grandi and European Commissioner for Home Affairs Ylva Johansson prepare to hold a news conference, at EU headquarters, in Brussels, Belgium May 10, 2021. Olivier Matthys/Pool via REUTERS

United Nations High Commissioner for Refugees Filippo Grandi and European Commissioner for Home Affairs Ylva Johansson prepare to hold a news conference, at EU headquarters, in Brussels, Belgium May 10, 2021. Olivier Matthys/Pool via REUTERS

Pupils from the worship group prepare music performance for a Church service at Colwich Church of England Primary School's new outdoor learning space, amid the spread of the coronavirus disease (COVID-19) in Colwich, Staffordshire, Britain May 10, 2021. REUTERS/Jason Cairnduff

Headteacher Alison De Ste Croix watches as pupils from the worship group prepare music performance for a Church service at Colwich Church of England Primary School's new outdoor learning space, amid the spread of the coronavirus disease (COVID-19) in Colwich, Staffordshire, Britain May 10, 2021. REUTERS/Jason Cairnduff

Pupils from the worship group prepare music performance for a Church service at Colwich Church of England Primary School's new outdoor learning space, amid the spread of the coronavirus disease (COVID-19) in Colwich, Staffordshire, Britain May 10, 2021. REUTERS/Jason Cairnduff

Pupils from the worship group prepare music performance for a Church service at Colwich Church of England Primary School's new outdoor learning space, amid the spread of the coronavirus disease (COVID-19) in Colwich, Staffordshire, Britain May 10, 2021. REUTERS/Jason Cairnduff

Pupils from the worship group prepare music performance for a Church service at Colwich Church of England Primary School's new outdoor learning space, amid the spread of the coronavirus disease (COVID-19) in Colwich, Staffordshire, Britain May 10, 2021. REUTERS/Jason Cairnduff

Sales assistant Yi Ling prepares her counter at Arnotts department store, as a phased reopening by appointment shopping following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Sales assistant Yi Ling prepares her counter at Arnotts department store, as a phased reopening by appointment shopping following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Staff members prepare vaccines at a New South Wales coronavirus disease (COVID-19) mass vaccination hub as it opens at Sydney Olympic Park in Sydney, Australia, May 10, 2021. James Gourley/Pool via REUTERS

A staff member prepares vaccines at a New South Wales coronavirus disease (COVID-19) mass vaccination hub as it opens at Sydney Olympic Park in Sydney, Australia, May 10, 2021. James Gourley/Pool via REUTERS

Staff members prepare vaccines at a New South Wales coronavirus disease (COVID-19) mass vaccination hub as it opens at Sydney Olympic Park in Sydney, Australia, May 10, 2021. James Gourley/Pool via REUTERS

A staff member prepares vaccines at a New South Wales coronavirus disease (COVID-19) mass vaccination hub as it opens at Sydney Olympic Park in Sydney, Australia, May 10, 2021. James Gourley/Pool via REUTERS

Staff members prepare vaccines at a New South Wales coronavirus disease (COVID-19) mass vaccination hub as it opens at Sydney Olympic Park in Sydney, Australia, May 10, 2021. James Gourley/Pool via REUTERS

A staff member prepares vaccines at a New South Wales coronavirus disease (COVID-19) mass vaccination hub as it opens at Sydney Olympic Park in Sydney, Australia, May 10, 2021. James Gourley/Pool via REUTERS

Workers prepare the medical supplies to be sent to India at the International Humanitarian City in Dubai, United Arab Emirates, May 9, 2021. REUTERS/Abdel Hadi Ramahi

Afghan men prepare victims' coffins for a mass funeral ceremony after yesterday's explosion in Kabul, Afghanistan May 9, 2021. REUTERS/Stringer

Olympics - Tokyo 2020 Olympic Games Test Event - Athletics - Olympic Stadium, Tokyo, Japan - May 9, 2021. Officials wearing protective face masks prepare for an event at the morning session of the Athletics test event. REUTERS/Issei Kato

Olympics - Tokyo 2020 Olympic Games Test Event - Athletics - Olympic Stadium, Tokyo, Japan - May 9, 2021. An official is seen amid preparations before the start of the morning session of the Athletics test event. REUTERS/Issei Kato

Olympics - Tokyo 2020 Olympic Games Test Event - Athletics - Olympic Stadium, Tokyo, Japan - May 9, 2021. Officials prepare before the start of the morning session of the Athletics test event. REUTERS/Issei Kato

Hellen Nanez, who lost 13 relatives to the coronavirus disease (COVID-19) and whose father is being treated for COVID-19 in the Intensive Care Unit, prepares plastic flowers she uses to present the handmade soaps she sells to help pay her father's medical bills, in Pisco, Peru, May 8, 2021. Picture taken May 8, 2021. REUTERS/Alessandro Cinque

Timothy Cheruiyot, 3rd L, winner of the 1500 meters gold medal at the 2019 World Athletics Championships in Doha, runs during a training session in Nairobi, Kenya, May 8, 2021. Picture taken May 8, 2021.REUTERS/Baz Ratner

Timothy Cheruiyot, winner of the 1500 meters gold medal at the 2019 World Athletics Championships in Doha, ties his shoes during a training session in Nairobi, Kenya, May 8, 2021. Picture taken May 8, 2021. REUTERS/Baz Ratner

Timothy Cheruiyot, 2nd R, winner of the 1500 meters gold medal at the 2019 World Athletics Championships in Doha, runs during a training session in Nairobi, Kenya, May 8, 2021.Picture taken May 8, 2021. REUTERS/Baz Ratner

Timothy Cheruiyot, winner of the 1500 meters gold medal at the 2019 World Athletics Championships in Doha, prepares for a training session in Nairobi, Kenya, May 8, 2021. Picture taken May 8, 2021. REUTERS/Baz Ratner

Timothy Cheruiyot, winner of the 1500 meters gold medal at the 2019 World Athletics Championships in Doha, warms up before a training session in Nairobi, Kenya, May 8, 2021. Picture taken May 8, 2021.REUTERS/Baz Ratner

Timothy Cheruiyot, 2nd L, winner of the 1500 meters gold medal at the 2019 World Athletics Championships in Doha, stretches before a training session in Nairobi, Kenya, May 8, 2021. Picture taken May 8, 2021. REUTERS/Baz Ratner

French President Emmanuel Macron and French Prime Minister Jean Castex prepare to lay a wreath of flowers at the tomb of the unknown soldier during a ceremony to mark the end of World War II at the Arc de Triomphe in Paris, , France May 8, 2021. REUTERS/Christian Hartmann/Pool

Israeli police officers tie barricades together at Damascus Gate in preparation for Laylat al-Qadr, or Night of Power, in Jerusalem's Old City May 8, 2021. REUTERS/Stephen Farrell

Muslims shop at a store in preparation for Eid al-Fitr, during a lockdown due to the coronavirus disease (COVID-19) outbreak, in Kuala Lumpur, Malaysia May 8, 2021. REUTERS/Lim Huey Teng

Olympics - Tokyo 2020 Olympic Games Test Event - Rhythmic Gymnastics - Ariake Gymnastics centre, Tokyo, Japan - May 8, 2021 Event staff prepare the floor before the event REUTERS/Kim Kyung-Hoon

Salvadoran army cadets prepare to participate in a military ceremony to commemorate the Salvadoran Soldier day in Antiguo Cuscatlan, El Salvador May 7, 2021. REUTERS/Jose Cabezas

Sherry, 17, holds her one-year-old son Ian as she leads a line of unaccompanied minors who were being prepared for transport with other asylum-seeking migrants from Central America after they crossed the Rio Grande river into the United States from Mexico, in La Joya, Texas, U.S., May 7, 2021. REUTERS/Adrees Latif

Sweden's Prime Minister Stefan Lofven takes off his protective face mask as he prepares to speak during the opening ceremony of an EU summit at the Alfandega do Porto Congress Center in Porto, Portugal May 7, 2021. Luis Vieira/Pool via REUTERS

Brazil's Foreign Minister Carlos Franca and Minister of Foreign Affairs, European Union and Cooperation in the Spanish government, Arancha Gonzalez Laya, prepare to pose for a photo before a meeting in Brasilia, Brazil, May 7, 2021. REUTERS/Ueslei Marcelino

Brazil's Foreign Minister Carlos Franca and Minister of Foreign Affairs, European Union and Cooperation in the Spanish government, Arancha Gonzalez Laya, prepare to pose for a photo before a meeting in Brasilia, Brazil, May 7, 2021. REUTERS/Ueslei Marcelino

Members of Somali National Army (SNA), who back the opposition, prepare to move to their barracks after reaching an agreement with the prime minister following clashes over the tenure of the president, in Mogadishu, Somalia May 7, 2021. REUTERS/Feisal Omar

Taher Abdelbaki, a doctor, prepares to receive a dose of the coronavirus disease (COVID-19) vaccine at Ibn Sina medical centre in rebel-held Idlib city, Syria, May 6, 2021. Picture taken May 6, 2021. REUTERS/Khalil Ashawi

A healthcare worker prepares a dose of the coronavirus disease (COVID-19) vaccine at Ibn Sina medical centre in rebel-held Idlib city, Syria, May 6, 2021. Picture taken May 6, 2021. REUTERS/Khalil Ashawi