(L-R) European Commission President Ursula von der Leyen, Belgium's Prime Minister Alexander De Croo, German scientist, CMO and co-founder of BioNTech Ozlem Tureci, Pfizer CEO Albert Bourla and Pfizer Manufacturing Belgium's Managing Director Luc Van Steenwinkel oversee the production of the Pfizer-BioNtech COVID-19 vaccine during a visit at the company's factory in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

European Commission President Ursula von der Leyen talks with Pfizer CEO Albert Bourla during a visit at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Pfizer CEO Albert Bourla oversees the production of the Pfizer-BioNTech COVID-19 vaccine during a visit at the company's factory in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

People attend Friday prayers during the holy fasting month of Ramadan after the government eased the coronavirus disease (COVID-19) restrictions, at al-Husseini mosque in Amman, Jordan April 23, 2021. REUTERS/Muath Freij

People attend Friday prayers during the holy fasting month of Ramadan after the government eased the coronavirus disease (COVID-19) restrictions, at al-Husseini mosque in Amman, Jordan April 23, 2021. REUTERS/Muath Freij

A closed backpackers hotel is seen as the country struggles with a third wave of infections of the coronavirus disease (COVID-19), in Sukhumvit road, in Bangkok, Thailand April 23, 2021. REUTERS/Jorge Silva

Tennis - ATP 500 - Barcelona Open - Real Club de Tennis Barcelona, Barcelona, Spain - April 23, 2021 Canada's Felix Auger Aliassime in action during his quarter final match against Greece's Stefanos Tsitsipas REUTERS/Albert Gea

A cyclist rides past a decommissioned British Airways Boeing 747 jumbo jet parked to be used for salvage and parts after the airline retired its whole 747 fleet, amongst the spread of the coronavirus disease (COVID-19) pandemic, Cotswold Airport, Kemble, Britain, April 23, 2021. REUTERS/Toby Melville

A motorbike is ridden past a decommissioned British Airways Boeing 747 jumbo jet parked to be used for salvage and parts after the airline retired its whole 747 fleet, amongst the spread of the coronavirus disease (COVID-19) pandemic, Cotswold Airport, Kemble, Britain, April 23, 2021. REUTERS/Toby Melville

A classic car is driven past a decommissioned British Airways Boeing 747 jumbo jet parked to be used for salvage and parts after the airline retired its whole 747 fleet, amongst the spread of the coronavirus disease (COVID-19) pandemic, Cotswold Airport, Kemble, Britain, April 23, 2021. REUTERS/Toby Melville

A cyclist rides past a decommissioned British Airways Boeing 747 jumbo jet parked to be used for salvage and parts after the airline retired its whole 747 fleet, amongst the spread of the coronavirus disease (COVID-19) pandemic, Cotswold Airport, Kemble, Britain, April 23, 2021. REUTERS/Toby Melville

European Commission President Ursula von der Leyen speaks to German scientist, CMO and co-founder of BioNTech Ozlem Tureci during a visit at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Pfizer CEO Albert Bourla oversees the production of the Pfizer-BioNTech COVID-19 vaccine during a visit at the company's factory in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

A closed bar is seen on Friday afternoon as the country struggles with a third wave of infections of the coronavirus disease (COVID-19, in Sukhumvit road, in Bangkok, Thailand April 23, 2021. REUTERS/Jorge Silva

Pfizer CEO Albert Bourla oversees the production of the Pfizer-BioNTech COVID-19 vaccine during a visit at the company's factory in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

A barber waits for customers as the country struggles with a third wave of infections of the coronavirus disease (COVID-19), in Sukhumvit road, in Bangkok, Thailand April 23, 2021. REUTERS/Jorge Silva

Pfizer CEO Albert Bourla oversees the production of the Pfizer-BioNTech COVID-19 vaccine during a visit at the company's factory in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Pfizer CEO Albert Bourla oversees the production of the Pfizer-BioNTech COVID-19 vaccine during a visit at the company's factory in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

European Commission President Ursula von der Leyen oversees the production of the Pfizer-BioNTech COVID-19 vaccine during a visit at the factory of U.S. pharmaceutical company Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

A closed go-go bar is seen on Friday afternoon as the country struggles with a third wave of infections of the coronavirus disease (COVID-19), in Bangkok, Thailand April 23, 2021. REUTERS/Jorge Silva

European Commission President Ursula von der Leyen speaks with Pfizer CEO Albert Bourla, Belgium's Prime Minister Alexander De Croo and German scientist, CMO and co-founder of BioNTech Ozlem Tureci during a visit at the factory of Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

European Commission President Ursula von der Leyen speaks with German scientist, CMO and co-founder of BioNTech Ozlem Tureci, Pfizer CEO Albert Bourla and Belgium's Prime Minister Alexander De Croo during a visit at the factory of Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

(L-R) European Commission President Ursula von der Leyen, Belgium's Prime Minister Alexander De Croo, Pfizer CEO Albert Bourla and German scientist, CMO and co-founder of BioNTech Ozlem Tureci, pose for a picture during a visit at the factory of Pfizer in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 Russia's Viktoria Listunova in action during the women's floor REUTERS/Arnd Wiegmann

(L-R) Pfizer CEO Albert Bourla, Belgium's Prime Minister Alexander De Croo, European Commission President Ursula von der Leyen and German scientist, CMO and co-founder of BioNTech Ozlem Tureci oversee the production of the Pfizer-BioNTech COVID-19 vaccine, during a visit at the factory in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

(L-R) Pfizer CEO Albert Bourla, Belgium's Prime Minister Alexander De Croo, European Commission President Ursula von der Leyen and German scientist, CMO and co-founder of BioNTech Ozlem Tureci oversee the production of the Pfizer-BioNTech COVID-19 vaccine, during a visit at the factory in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

European Commission President Ursula von der Leyen (R) talks with Pfizer CEO Albert Bourla (L), Belgium's Prime Minister Alexander De Croo (R-back) and German scientist, CMO and co-founder of BioNTech Ozlem Tureci (2nd L) during a visit at the factory of U.S. pharmaceutical company Pfizer, to oversee the production of the Pfizer-BioNTech COVID-19 vaccine, in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

A closed bar is seen on Friday afternoon as the country struggles with a third wave of infections of the coronavirus disease (COVID-19), in Sukhumvit road, in Bangkok, Thailand April 23, 2021. REUTERS/Jorge Silva

A closed bar is seen on Friday afternoon as the country struggles with a third wave of infections of the coronavirus disease (COVID-19), in Sukhumvit road, in Bangkok, Thailand April 23, 2021. REUTERS/Jorge Silva

Tennis - WTA 500 - Stuttgart Open - Porsche-Arena, Stuttgart, Germany - April 23, 2021 Czech Republic’s Karolina Pliskova reacts during her quarter final match against Australia's Ashleigh Barty Pool via REUTERS/Marijan Murat

Tennis - WTA 500 - Stuttgart Open - Porsche-Arena, Stuttgart, Germany - April 23, 2021 Czech Republic’s Karolina Pliskova in action during her quarter final match against Australia's Ashleigh Barty Pool via REUTERS/Marijan Murat

A woman prepares tables at a street food stall as the country struggles with a third wave of infections of the coronavirus disease (COVID-19), in Bangkok, Thailand April 23, 2021. REUTERS/Jorge Silva

Tennis - WTA 500 - Stuttgart Open - Porsche-Arena, Stuttgart, Germany - April 23, 2021 Australia's Ashleigh Barty in action during her quarter final match against Czech Republic’s Karolina Pliskova Pool via REUTERS/Marijan Murat

European Commission President Ursula von der Leyen arrives at the factory of U.S. pharmaceutical company Pfizer, to oversee the production of the Pfizer-BioNTech COVID-19 vaccine, in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

Tennis - ATP 500 - Barcelona Open - Real Club de Tennis Barcelona, Barcelona, Spain - April 23, 2021 Canada's Felix Auger Aliassime in action during his quarter final match against Greece's Stefanos Tsitsipas REUTERS/Albert Gea

European Commission President Ursula von der Leyen arrives at the factory of U.S. pharmaceutical company Pfizer, to oversee the production of the Pfizer-BioNTech COVID-19 vaccine, in Puurs, Belgium April 23, 2021. John Thys /Pool via REUTERS

German Chancellor Angela Merkel leaves after testifying before a parliament committee investigating Wirecard, in Berlin, Germany April 23, 2021. REUTERS/Michele Tantussi

Managing Director of Devji, a major jewellery manufacture and retailer, Jaydeep Bharatji, speaks during an interview with Reuters at his company's headquarters in Hidd, Bahrain, April 20, 2021. Picture taken April 20, 2021. REUTERS/Hamad I Mohammed

Gymnastics - 2021 European Artistic Gymnastics Championships - St. Jakobshalle, Basel, Switzerland - April 23, 2021 France's Carolann Heduit in action during the womens floor REUTERS/Arnd Wiegmann

Britain's Prime Minister Boris Johnson meets members of the National Farmers Union, as part of a Conservative party local election visit at Moor Farm in Stoney Middleton, England, Friday, April 23, 2021. Rui Vieira/Pool via REUTERS

A man wearing a protective mask walks amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan April 23, 2021. REUTERS/Issei Kato

Noora Jamsheer, Chief Executive Officer of DANAT, (Bahrain's Institute for Pearls and Gemstones gemological laboratory, education and research centre) attends an interview with Reuters at her office in Manama, Bahrain, April 22, 2021. Picture taken April 22, 2021. REUTERS/Hamad I Mohammed

Japanese Prime Minister Yoshihide Suga and Shigeru Omi, President of the Japan Community Health Care Organization, hold a press conference on COVID-19 situation in Tokyo, Japan April 23, 2021. Yuichi Yamazaki/Pool via REUTERS

German Chancellor Angela Merkel leaves after testifying before a parliament committee investigating Wirecard, in Berlin, Germany April 23, 2021. REUTERS/Michele Tantussi

People wearing protective masks walk on the street, amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan April 23, 2021. REUTERS/Issei Kato

Britain's Prime Minister Boris Johnson feeds a lamb alongside Hayley Fairfax and Sarah Fairfax, as part of a Conservative party local election visit at Moor Farm in Stoney Middleton, England, Friday, April 23, 2021. Rui Vieira/Pool via REUTERS

Britain's Prime Minister Boris Johnson feeds a lamb, as part of a Conservative party local election visit at Moor Farm in Stoney Middleton, England, Friday, April 23, 2021. Rui Vieira/Pool via REUTERS

Jewellery artisans manufacture gold jewellery at Devji, a major manufacturer and retailer, in Hidd, Bahrain, April 20, 2021. Picture taken April 20, 2021. REUTERS/Hamad I Mohammed

Britain's Prime Minister Boris Johnson feeds a lamb, as part of a Conservative party local election visit at Moor Farm in Stoney Middleton, England, Friday, April 23, 2021. Rui Vieira/Pool via REUTERS

Britain's Prime Minister Boris Johnson feeds a lamb, as part of a Conservative party local election visit at Moor Farm in Stoney Middleton, England, Friday, April 23, 2021. Rui Vieira/Pool via REUTERS

Japanese Prime Minister Yoshihide Suga speaks during a press conference on COVID-19 situation in Tokyo, Japan April 23, 2021. Yuichi Yamazaki/Pool via REUTERS

Japanese Prime Minister Yoshihide Suga speaks during a press conference on COVID-19 situation in Tokyo, Japan April 23, 2021. Yuichi Yamazaki/Pool via REUTERS

A staff member of a Japanese izakaya pub or restaurant prepares to close the shop amid the coronavirus disease (COVID-19) outbreak, in Tokyo, Japan April 23, 2021. REUTERS/Issei Kato

Jewellery artisans manufacture gold jewellery at Devji, a major manufacturer and retailer, in Hidd, Bahrain, April 20, 2021. Picture taken April 20, 2021. REUTERS/Hamad I Mohammed

Tennis - ATP 500 - Barcelona Open - Real Club de Tennis Barcelona, Barcelona, Spain - April 23, 2021 Greece's Stefanos Tsitsipas reacts during his quarter final match against Canada's Felix Auger Aliassime REUTERS/Albert Gea

Japanese Prime Minister Yoshihide Suga speaks during a press conference on COVID-19 situation in Tokyo, Japan April 23, 2021. Yuichi Yamazaki/Pool via REUTERS

Tennis - ATP 500 - Barcelona Open - Real Club de Tennis Barcelona, Barcelona, Spain - April 23, 2021 Greece's Stefanos Tsitsipas in action during his quarter final match against Canada's Felix Auger Aliassime REUTERS/Albert Gea

Japanese Prime Minister Yoshihide Suga speaks during a press conference on COVID-19 situation in Tokyo, Japan April 23, 2021. Yuichi Yamazaki/Pool via REUTERS

Japanese Prime Minister Yoshihide Suga speaks during a press conference on COVID-19 situation in Tokyo, Japan April 23, 2021. Yuichi Yamazaki/Pool via REUTERS

ESA astronaut Thomas Pesquet, NASA astronauts Shane Kimbrough and Megan McArthur, and JAXA astronaut Akihiko Hoshide arrive for the boarding of the SpaceX Falcon 9 rocket with the Crew Dragon capsule, before the launch of the NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Joe Skipper

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission to the International Space Station at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Thom Baur

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Thom Baur

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission to the International Space Station at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Thom Baur

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission to the International Space Station at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Joe Skipper

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Thom Baur TPX IMAGES OF THE DAY

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Steve Nesius

JAXA astronaut Akihiko Hoshide reacts as he arrives for the boarding of the SpaceX Falcon 9 rocket with the Crew Dragon capsule, before the launch of the NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Joe Skipper

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Thom Baur

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission to the International Space Station at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Joe Skipper

ESA astronaut Thomas Pesquet, NASA astronauts Shane Kimbrough and Megan McArthur, and JAXA astronaut Akihiko Hoshide arrive for the boarding of the SpaceX Falcon 9 rocket with the Crew Dragon capsule, before the launch of the NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Joe Skipper

A SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Thom Baur

SpaceX founder Elon Musk arrives ahead of the launch of the SpaceX Falcon 9 rocket with the Crew Dragon capsule, before launch of their NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Joe Skipper

The sky glows as a SpaceX Falcon 9 rocket, with the Crew Dragon capsule, is launched carrying four astronauts on a NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Steve Nesius

NASA astronauts Shane Kimbrough and Megan McArthur, JAXA astronaut Akihiko Hoshide and ESA astronaut Thomas Pesquet arrive for the boarding of the SpaceX Falcon 9 rocket with the Crew Dragon capsule, before the launch of the NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Joe Skipper

SpaceX founder Elon Musk arrives ahead of the launch of the SpaceX Falcon 9 rocket with the Crew Dragon capsule, before launch of their NASA commercial crew mission at Kennedy Space Center in Cape Canaveral, Florida, U.S., April 23, 2021. REUTERS/Joe Skipper