People register to receive a dose of the "Comirnaty" Pfizer BioNTech COVID-19 vaccine in a vaccination center in Reze near Nantes as part of the coronavirus disease (COVID-19) vaccination campaign in France, May 6, 2021. REUTERS/Stephane Mahe

A healthcare worker registers to receive a dose of the coronavirus disease (COVID-19) vaccine at a hospital in Idlib, Syria, May 1, 2021. REUTERS/Khalil Ashawi

People get their names registered after receiving a dose of COVISHIELD, a coronavirus disease (COVID-19) vaccine manufactured by Serum Institute of India, at a vaccination centre in Ahmedabad, India, May 1, 2021. REUTERS/Amit Dave

Advanced registered nurse practitioner Dawda Cham vaccinates a patient against the coronavirus disease (COVID-19), at a clinic held by 6M Geriatrics and accompanied by live music from an organist, at Saint Mark's Episcopal Cathedral in the Capitol Hill district of Seattle, Washington, U.S. April 29, 2021. REUTERS/Lindsey Wasson

Advanced registered nurse practitioner Dawda Cham waits for another patient during a coronavirus disease (COVID-19) vaccination clinic held by 6M Geriatrics, accompanied by live music from an organist at Saint Mark's Episcopal Cathedral in the Capitol Hill district of Seattle, Washington, U.S. April 29, 2021. REUTERS/Lindsey Wasson

Advanced registered nurse practitioner Dawda Cham administers a coronavirus disease (COVID-19) vaccine at a clinic held by 6M Geriatrics, accompanied by live music from an organist, at Saint Mark's Episcopal Cathedral in the Capitol Hill district of Seattle, Washington, U.S. April 29, 2021. REUTERS/Lindsey Wasson

Advanced registered nurse practitioner Dawda Cham administers a vaccination against the coronavirus disease (COVID-19), accompanied by live music from an organist, at a clinic held by 6M Geriatrics at Saint Mark's Episcopal Cathedral in the Capitol Hill district of Seattle, Washington, U.S. April 29, 2021. REUTERS/Lindsey Wasson

Advanced registered nurse practitioner Dawda Cham walks past people undergoing their wait period after receiving a coronavirus disease (COVID-19) vaccine at a clinic held by 6M Geriatrics, accompanied by live music from an organist, at Saint Mark's Episcopal Cathedral in the Capitol Hill district of Seattle, Washington, U.S. April 29, 2021. REUTERS/Lindsey Wasson

People register for their vaccine against the coronavirus disease (COVID-19) at Suvarnabhumi airport in Bangkok, Thailand April 28, 2021. REUTERS/Jorge Silva

People register for their vaccine against the coronavirus disease (COVID-19) at Suvarnabhumi airport in Bangkok, Thailand April 28, 2021. REUTERS/Jorge Silva

People register to receive a dose of the "Comirnaty" Pfizer BioNTech COVID-19 vaccine at the Disneyland Paris theme park vaccination center in Marne-la-Vallee, near Paris, as part of the coronavirus disease (COVID-19) vaccination campaign in France, April 24, 2021. REUTERS/Benoit Tessier

People register to receive a dose of the "Comirnaty" Pfizer BioNTech COVID-19 vaccine at the Disneyland Paris theme park vaccination center in Marne-la-Vallee, near Paris, as part of the coronavirus disease (COVID-19) vaccination campaign in France, April 24, 2021. REUTERS/Benoit Tessier

Olivia Coughlin, a registered healthcare social worker, calls the family of a coronavirus disease (COVID-19) patient who died inside the intensive care unit of Humber River Hospital in Toronto, Ontario, Canada April 15, 2021. Picture taken April 15, 2021. REUTERS/Carlos Osorio

A woman registers details to get a hospital bed for her relative who needs treatment for the coronavirus disease at the COVID-19 Integrated Control and Command Centre in Lucknow, India, April 20, 2021. Picture taken April 20, 2021. REUTERS/Pawan Kumar

View of external door of the office registered to the companies N2N Art Gallery, Enhanced Recovery Company Middle East and Republik Real Estate, in Addax Tower, Abu Dhabi, United Arab Emirates March 9, 2021. Picture taken March 9, 2021. REUTERS/Alexander Cornwell

A man has his personal information registered as he arrives to receive a dose of the AstraZeneca coronavirus disease (COVID-19) vaccine, in Tripoli, Libya, April 17, 2021. REUTERS/Hazem Ahmed

Volunteer registered nurses from all over New Mexico give people coronavirus disease (COVID-19) vaccines at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. REUTERS/Paul Ratje

Registered Nurse Pat Heinen waits for more patients to arrive to receive coronavirus disease (COVID-19) vaccines at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. REUTERS/Paul Ratje

Registered Nurse Cathy Boyle gives Obed Vargas a coronavirus disease (COVID-19) vaccine at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. REUTERS/Paul Ratje

Taras Mychalewych, 75, is shown his vaccination card by volunteer registered nurse Cathy Boyle, after receiving his coronavirus disease (COVID-19) vaccine at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. REUTERS/Paul Ratje

Registered nurse Cathy Faulkner gives Natanael Gómez his coronavirus disease (COVID-19) vaccine at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. REUTERS/Paul Ratje

Registered nurse Pat Heinen gives Genard Chavez his coronavirus disease (COVID-19) vaccine at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. REUTERS/Paul Ratje

Farm worker Roberto Guerra receives his coronavirus disease (COVID-19) vaccine from volunteer registered nurse Kyla Walker at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. REUTERS/Paul Ratje

Staff members sit at desks to register people for a shot of a vaccine against the coronavirus disease (COVID-19) at a vaccination center, during a government-organized visit, in Beijing, China, April 15, 2021. REUTERS/Thomas Peter

The registered nurse, Catherine Serrano, from Humber River Hospital's mobile vaccine clinic departs after administering the Moderna COVID-19 vaccine at a Toronto Community Housing building, as part of the coronavirus disease (COVID-19) vaccination campaign, in Toronto, Ontario, Canada April 13, 2021. REUTERS/Carlos Osorio

A general view shows people registering to get a dose of the "Comirnaty" Pfizer BioNTech COVID-19 vaccine at the Parc des Expositions in Angers as part of the coronavirus disease (COVID-19) vaccination campaign in France, April 13, 2021. REUTERS/Stephane Mahe

People register to get a dose of the "Comirnaty" Pfizer BioNTech COVID-19 vaccine at the Parc des Expositions in Angers as part of the coronavirus disease (COVID-19) vaccination campaign in France, April 13, 2021. REUTERS/Stephane Mahe

A general view shows people registering to get a dose of the "Comirnaty" Pfizer BioNTech COVID-19 vaccine at the Parc des Expositions in Angers as part of the coronavirus disease (COVID-19) vaccination campaign in France, April 13, 2021. REUTERS/Stephane Mahe

A general view shows people registering to get a dose of the "Comirnaty" Pfizer BioNTech COVID-19 vaccine at the Parc des Expositions in Angers as part of the coronavirus disease (COVID-19) vaccination campaign in France, April 13, 2021. REUTERS/Stephane Mahe

A registered citizen waits for a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine in the eastern German town of Weisswasser, Germany, April 9, 2021. REUTERS/Michaela Rehle

Town hall personnel register invited citizens before they receive a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine in the eastern German town of Weisswasser, Germany, April 9, 2021. REUTERS/Michaela Rehle

Town hall personnel register invited citizens before they receive a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine in the eastern German town of Weisswasser, Germany, April 9, 2021. REUTERS/Michaela Rehle

Registered citizens wait for a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine in the eastern German town of Weisswasser, Germany, April 9, 2021. REUTERS/Michaela Rehle

Town hall personnel register invited citizens before they receive a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine in the eastern German town of Weisswasser, Germany, April 9, 2021. REUTERS/Michaela Rehle

Town hall personnel register invited citizens before they receive a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine in the eastern German town of Weisswasser, Germany, April 9, 2021. REUTERS/Michaela Rehle

Town hall personnel register invited citizens before they receive a dose of the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine in the eastern German town of Weisswasser, Germany, April 9, 2021. REUTERS/Michaela Rehle

People wearing protective face masks wait in line to register for coronavirus disease (COVID-19) vaccines in the Sunset Park section of the Brooklyn borough of New York, U.S., April 7, 2021. REUTERS/Shannon Stapleton

People wearing protective face masks wait in line to register for coronavirus disease (COVID-19) vaccines in the Sunset Park section of the Brooklyn borough of New York, U.S., April 7, 2021. REUTERS/Shannon Stapleton

People wearing protective face masks wait in line to register for coronavirus disease (COVID-19) vaccines in the Sunset Park section of the Brooklyn borough of New York, U.S., April 7, 2021. REUTERS/Shannon Stapleton

People wearing protective face masks wait in line to register for coronavirus disease (COVID-19) vaccines in the Sunset Park section of the Brooklyn borough of New York, U.S., April 7, 2021. REUTERS/Shannon Stapleton

A registered nurse sits at a vaccination area for people receiving the Johnson & Johnson coronavirus disease (COVID-19) vaccine at a NYC mobile vaccine bus in the Sunset Park section of the Brooklyn borough of New York, U.S., April 7, 2021. REUTERS/Shannon Stapleton

A registered nurse sits at a vaccination area for people receiving the Johnson & Johnson coronavirus disease (COVID-19) vaccine at a NYC mobile vaccine bus in the Sunset Park section of the Brooklyn borough of New York, U.S., April 7, 2021. REUTERS/Shannon Stapleton

A child has her nasal swab applied for the coronavirus disease (COVID-19) test as others register at a mobile testing site in the Queens borough of New York, U.S., April 5, 2021. REUTERS/Shannon Stapleton

A child has her nasal swab applied for the coronavirus disease (COVID-19) test as others register at a mobile testing site in the Queens borough of New York, U.S., April 5, 2021. REUTERS/Shannon Stapleton

People register for the coronavirus disease (COVID-19) vaccination at the fairgrounds in Berlin, Germany, April 5, 2021. Michael Kappeler/Pool via REUTERS

A person registers for the coronavirus disease (COVID-19) vaccine at the fairgrounds in Berlin, Germany, April 5, 2021. Michael Kappeler/Pool via REUTERS

Nasser Al-Qudwa arrives to register a list for the upcoming Palestinian parliamentary elections, in Ramallah in the Israeli-occupied West Bank March 31, 2021. REUTERS/Ali Sawafta

Jibril Rajoub, a senior Fatah official arrives to register Fatah list for the upcoming parliamentary elections, in Ramallah in the Israeli-occupied West Bank March 31, 2021. REUTERS/Ali Sawafta

Khalil al-Hayya, Hamas's deputy leader in Gaza, arrives with other representatives to register Hamas's list for the upcoming parliamentary elections, in Gaza City March 29, 2021. Picture taken March 29, 2021. REUTERS/Mohammed Salem

Hamas members arrive to register their list for the upcoming parliamentary elections, in Gaza City March 29, 2021. Picture taken March 29, 2021. REUTERS/Mohammed Salem

Teachers wait to register to receive a dose of the Sinovac's CoronaVac coronavirus disease (COVID-19) vaccine at a public health center in Cuscatancingo, El Salvador March 30, 2021. REUTERS/Jose Cabezas

Teachers wait to register to receive a dose of the Sinovac's CoronaVac coronavirus disease (COVID-19) vaccine, at a public health center in Cuscatancingo, El Salvador March 30, 2021. REUTERS/Jose Cabezas

A couple register to receive the "Comirnaty" Pfizer-BioNTech COVID-19 vaccine in a vaccination center in Antibes as part of the coronavirus disease vaccination campaign in France, March 29, 2021. REUTERS/Eric Gaillard

A woman registers to receive the "Comirnaty" Pfizer-BioNTech COVID-19 vaccine in a vaccination center in Antibes as part of the coronavirus disease vaccination campaign in France, March 29, 2021. REUTERS/Eric Gaillard

A woman registers to receive the "Comirnaty" Pfizer-BioNTech COVID-19 vaccine in a vaccination center in Antibes as part of the coronavirus disease vaccination campaign in France, March 29, 2021. REUTERS/Eric Gaillard

Hamas representatives arrive to register their list for the upcoming parliamentary elections, in Ramallah in the Israeli-occupied West Bank March 29, 2021. REUTERS/Ali Sawafta

Khalil al-Hayya, Hamas's deputy leader in Gaza, arrives with other representatives to register Hamas's list for the upcoming parliamentary elections, in Gaza City March 29, 2021. REUTERS/Mohammed Salem

Khalil al-Hayya, Hamas's deputy leader in Gaza, arrives with other representatives to register Hamas's list for the upcoming parliamentary elections, in Gaza City March 29, 2021. REUTERS/Mohammed Salem

Hamas members arrive to register their list for the upcoming parliamentary elections, in Gaza City March 29, 2021. REUTERS/Mohammed Salem

Khalil al-Hayya, Hamas's deputy leader in Gaza, arrives with other representatives to register Hamas's list for the upcoming parliamentary elections, in Gaza City March 29, 2021. REUTERS/Mohammed Salem