Belgian artist Alain Verschueren wears his "Portable Oasis" while performing in a street, saying he wanted to be in his bubble in the middle of the city, amid the coronavirus disease (COVID-19) outbreak in Brussels, Belgium April 16, 2021. Picture taken April 16, 2021. REUTERS/Yves Herman

Belgian artist Alain Verschueren wears his "Portable Oasis" while performing in a street, saying he wanted to be in his bubble in the middle of the city, amid the coronavirus disease (COVID-19) outbreak in Brussels, Belgium April 16, 2021. Picture taken April 16, 2021. REUTERS/Yves Herman

Belgian artist Alain Verschueren wears his "Portable Oasis" while performing in a street, saying he wanted to be in his bubble in the middle of the city, amid the coronavirus disease (COVID-19) outbreak in Brussels, Belgium April 16, 2021. Picture taken April 16, 2021. REUTERS/Yves Herman

Belgian artist Alain Verschueren wears his "Portable Oasis" while performing in a street, saying he wanted to be in his bubble in the middle of the city, amid the coronavirus disease (COVID-19) outbreak in Brussels, Belgium April 16, 2021. Picture taken April 16, 2021. REUTERS/Yves Herman

Belgian artist Alain Verschueren wears his "Portable Oasis" while performing in a street, saying he wanted to be in his bubble in the middle of the city, amid the coronavirus disease (COVID-19) outbreak in Brussels, Belgium April 16, 2021. Picture taken April 16, 2021. REUTERS/Yves Herman

Belgian artist Alain Verschueren wears his "Portable Oasis" while performing in a street, saying he wanted to be in his bubble in the middle of the city, amid the coronavirus disease (COVID-19) outbreak in Brussels, Belgium April 16, 2021. Picture taken April 16, 2021. REUTERS/Yves Herman

Belgian artist Alain Verschueren wears his "Portable Oasis" while performing in a street, saying he wanted to be in his bubble in the middle of the city, amid the coronavirus disease (COVID-19) outbreak in Brussels, Belgium April 16, 2021. Picture taken April 16, 2021. REUTERS/Yves Herman

Training nurse Sari Roos prepares a dose of AstraZeneca vaccine against coronavirus disease (COVID-19) to teach her air bubble technique in Laakso hospital in Helsinki, Finland March 11, 2021. Picture taken March 11, 2021. REUTERS/Essi Lehto

Training nurse Sari Roos prepares a dose of AstraZeneca vaccine against coronavirus disease (COVID-19) to teach her air bubble technique in Laakso hospital in Helsinki, Finland March 11, 2021. Picture taken March 11, 2021. REUTERS/Essi Lehto

Training nurse Sari Roos prepares a dose of Pfizer/BioNTech vaccine against coronavirus disease (COVID-19) to teach her air bubble technique in Laakso hospital in Helsinki, Finland March 11, 2021. Picture taken March 11, 2021. REUTERS/Essi Lehto

Training nurse Sari Roos prepares a dose of AstraZeneca vaccine against coronavirus disease (COVID-19) to teach her air bubble technique in Laakso hospital in Helsinki, Finland March 11, 2021. Picture taken March 11, 2021. REUTERS/Essi Lehto

Training nurse Sari Roos prepares a dose of AstraZeneca vaccine against coronavirus disease (COVID-19) to teach her air bubble technique in Laakso hospital in Helsinki, Finland March 11, 2021. Picture taken March 11, 2021. REUTERS/Essi Lehto

A man waring a protective face mask makes soap bubbles following the easing of measures against the spread of the coronavirus disease (COVID-19) in Faliro suburb, near Athens, Greece, April 3, 2021. REUTERS/Costas Baltas TPX IMAGES OF THE DAY

A man waring a protective face mask makes soap bubbles following the easing of measures against the spread of the coronavirus disease (COVID-19) in Faliro suburb, near Athens, Greece, April 3, 2021. REUTERS/Costas Baltas

Palau President Surangel Whipps speaks before boarding the plane with passengers travelling on the travel bubble flight to Palau during the coronavirus disease (COVID-19) pandemic, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

Palau President Surangel Whipps, wearing a face mask following the coronavirus disease (COVID-19) outbreak, speaks before boarding the plane with passengers travelling on the travel bubble flight to Palau, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

Palau President Surangel Whipps and his wife Valerie, wearing face masks following the coronavirus disease (COVID-19) outbreak, wave before boarding the plane with passengers travelling on the travel bubble flight to Palau, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

Travellers, wearing face masks following the coronavirus disease (COVID-19) outbreak, enter the boarding gate for the travel bubble flight to Palau, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

U.S. Ambassador to Palau John Hennessey-Niland, wearing a face mask following the coronavirus disease (COVID-19) outbreak, walks before boarding the plane with passengers travelling on the travel bubble flight to Palau, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

Palau President Surangel Whipps and his wife Valerie, wearing face masks following the coronavirus disease (COVID-19) outbreak, wave before boarding the plane with passengers travelling on the travel bubble flight to Palau, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

Palau President Surangel Whipps, wearing a face mask following the coronavirus disease (COVID-19) outbreak, waves next to his wife Valerie and Taiwan Foreign Minister Joseph Wu before boarding the plane with passengers travelling on the travel bubble flight to Palau, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

Travellers, wearing face masks following the coronavirus disease (COVID-19) outbreak, pose with a banner before their travel bubble flight to Palau, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

A traveller, wearing a face mask following the coronavirus disease (COVID-19) outbreak, poses with luggage before the travel bubble flight to Palau, at Taoyuan International Airport in Taoyuan, Taiwan April 1, 2021. REUTERS/Ann Wang

A man plays soccer while two kids play with bubbles with a woman near the Washington Monument in Washington, U.S. March 27, 2021. REUTERS/Cheriss May

A woman plays with a child and bubbles near the Washington Monument in Washington, U.S. March 27, 2021. REUTERS/Cheriss May

A girl stands inside a giant bubble at Central Park on spring equinox, in the Manhattan borough of New York City, New York, U.S., March 20, 2021. REUTERS/Caitlin Ochs

A girl chases bubbles at Central Park on spring equinox, in the Manhattan borough of New York City, New York, U.S., March 20, 2021. REUTERS/Caitlin Ochs

A demonstrator makes soap bubbles as he attends a protest against the government's coronavirus disease (COVID-19) restrictions in Kassel, Germany March 20, 2021. REUTERS/Thilo Schmuelgen

A demonstrator makes soap bubbles as he attends a protest against the government's coronavirus disease (COVID-19) restrictions in Kassel, Germany March 20, 2021. REUTERS/Thilo Schmuelgen

Eateries stand on a street near the Tokyo Stock Exchange building at Kayabacho district in Tokyo, Japan, February 25, 2021. Picture taken on February 25, 2021. REUTERS/Junko Fujita

Kenichi Inoue, the owner of a restaurant named "Wall Street" stands at the entrance of the diner at Kayabacho district in Tokyo, Japan, February 25, 2021. Picture taken on February 25, 2021. REUTERS/Junko Fujita

Kenichi Inoue, the owner of a restaurant named "Wall Street" stands at the entrance of the diner at Kayabacho district in Tokyo, Japan, February 25, 2021. Picture taken on February 25, 2021. REUTERS/Junko Fujita

Eateries stand on a street near the Tokyo Stock Exchange building at Kayabacho district in Tokyo, Japan, February 25, 2021. Picture taken on February 25, 2021. REUTERS/Junko Fujita

A meeting room outfitted with airtight glass panels is pictured at short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of a meeting room outfitted with airtight glass panels at short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A hand sanitiser dispenser is pictured at the lobby of short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A staff member shows how food is delivered to rooms at the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A staff member shows how food is delivered in a compartment outside a room of the short-stay facility Connect@Changi, which will welcome business "bubble" travellers from March as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A staff member shows how documents could be sanitised and exchanged in a special window of a meeting room at short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A worker paints a corridor of a short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

Workers make final touch-ups to the rooms at the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

An access gate leads to a courtyard of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of a courtyard of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of pavilions and a gym in the courtyard of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of pod-like rest areas in the pavilion of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

Grass-like LED lamps light up the courtyard of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A staff member shows how face-to-face meetings can be conducted in a meeting room outfitted with airtight glass panels at short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A receptionist wearing a face shield sits in the lobby of short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of a room at the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

Receptionists wear face shields at the business centre of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A meeting room outfitted with air-tight glass panels to reduce the risk of transmission, is pictured at the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of a meeting room outfitted with airtight glass panels at short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of a waiting area at the testing station of short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of a waiting area at the testing station of short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A receptionist wearing a face shield sits in the lobby of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A view of the lobby of the short-stay facility Connect@Changi, a complex of hotel rooms and meeting halls near the airport which will welcome business "bubble" travellers from March, as part of the city-state's effort to resume international meetings and conferences amid the coronavirus disease (COVID-19) outbreak, in Singapore February 22, 2021. REUTERS/Edgar Su

A man sits in a bubble tent as the spread of the coronavirus disease (COVID-19) continues, in New York City, New York, U.S., February 4, 2021. REUTERS/Jeenah Moon

A man sits in a bubble tent as the spread of the coronavirus disease (COVID-19) continues, in New York City, New York, U.S., February 4, 2021. REUTERS/Jeenah Moon

A man makes soap bubbles during a protest against restrictions put in place to curb the spread of the coronavirus disease (COVID-19), in Amsterdam, Netherlands January 31, 2021. REUTERS/Stringer REFILE - CORRECTING LOCATION