Deputy charge nurse Katie McIntosh administers the first of two Pfizer/BioNTech COVID-19 vaccine jabs, to Clinical Lead of Outpatient Theatres Andrew Mencnarowski, at the Western General Hospital, on the first day of the largest immunisation programme in the British history, in Edinburgh, Scotland Britain December 8, 2020. Andrew Milligan/Pool via REUTERS

Deputy charge nurse Katie McIntosh shows leaflets to Clinical Lead of Outpatient Theatres Andrew Mencnarowski after she administered the first of two Pfizer/BioNTech COVID-19 vaccine jabs, the Western General Hospital, on the first day of the largest immunisation programme in the British history, in Edinburgh, Scotland Britain December 8, 2020. Andrew Milligan/Pool via REUTERS

Clinical Lead of Outpatient Theatres Andrew Mencnarowski, who will be the hospital's first to receive a COVID-19 vaccine, rolls up his sleeve as Scotland's First Minister Nicola Sturgeon visits Western General Hospital amid the spread of the coronavirus disease (COVID-19) in Edinburgh, Scotland, Britain, December 7, 2020. REUTERS/Russell Cheyne/Pool

A man receives medical treatment by doctor Anna Dalmau, 29, at an outpatient center, after Catalonia's government imposed new restrictions in an effort to control the spread of the coronavirus disease (COVID-19), in Barcelona, Spain November 17, 2020. Picture taken November 17, 2020. REUTERS/Nacho Doce

Doctor Anna Dalmau, 29, poses in the corridor of an outpatient center, after Catalonia's government imposed new restrictions in an effort to control the spread of the coronavirus disease (COVID-19), in Barcelona, Spain, November 17, 2020. Picture taken November 17, 2020. REUTERS/Nacho Doce

A man receives medical treatment by doctor Anna Dalmau, 29, at an outpatient center, after Catalonia's government imposed new restrictions in an effort to control the spread of the coronavirus disease (COVID-19), in Barcelona, Spain November 17, 2020. Picture taken November 17, 2020. REUTERS/Nacho Doce

Nurses wait for patients to be tested for coronavirus disease (COVID-19) at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Miriam Fuentes-Alonso waits for patients to arrive to receive a test for coronavirus disease (COVID-19) at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurses wait for a patient in a car to pull forward to be tested for coronavirus disease (COVID-19) at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

A nurse administers a test for coronavirus disease (COVID-19) to a patient at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Miriam Fuentes-Alonso holds a sign as a patient arrives to receive a test for coronavirus disease (COVID-19) at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

A nurse changes her personal protective equipment after administering a test for coronavirus disease (COVID-19) to a patient at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Miriam Fuentes-Alonso poses for a portrait while staffing a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurses Yedda Pelingon, Theresa Malijan, and Miriam Fuentes-Alonso pose for a portrait while staffing a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Miriam Fuentes-Alonso poses for a portrait while staffing a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Theresa Malijan poses for a portrait while staffing a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Corazon Morales poses for a portrait while staffing a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Theresa Malijan administers a test for coronavirus disease (COVID-19) to a patient at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Theresa Malijan administers a test for coronavirus disease (COVID-19) to a patient at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 18, 2020. REUTERS/David Ryder

Nurse Teresa Malijon wearing a protective gear waits for patients at a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center in Seattle, Washington, U.S., March 17, 2020. REUTERS/Brian Snyder

Nurses Teresa Malijon and Corazon Morales administer a test for coronavirus disease (COVID-19) to a patient at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center in Seattle, Washington, U.S., March 17, 2020. REUTERS/Brian Snyder

Nurse Corazon Morales wearing a protective gear administers a test for coronavirus disease (COVID-19) to a patient at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center in Seattle, Washington, U.S., March 17, 2020. REUTERS/Brian Snyder

Nurse Corazon Morales wearing a protective gear administers a test for coronavirus disease (COVID-19) to a patient at a drive-through testing site in a parking lot at the University of Washington's Northwest Outpatient Medical Center in Seattle, Washington, U.S., March 17, 2020. REUTERS/Brian Snyder

Medical assistant Miriam Fuentes wearing a protective gear waits for patients at a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center in Seattle, Washington, U.S., March 17, 2020. REUTERS/Brian Snyder

Nurses wearing protective gear wait for patients at a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center in Seattle, Washington, U.S., March 17, 2020. REUTERS/Brian Snyder

Nurses wearing protective gear wait for patients at a drive-through testing site for coronavirus disease (COVID-19) in a parking lot at the University of Washington's Northwest Outpatient Medical Center in Seattle, Washington, U.S., March 17, 2020. REUTERS/Brian Snyder

A woman wears a face mask, as she walks outside San Rafael Hospital, after health authorities decided to suspend outpatient services for three days, due to the involvement of workers and patients after a coranovirus outbreak, according to the press release of the Ministry of Health, in Alajuela, Costa Rica March 9, 2020. REUTERS/Juan Carlos Ulate

A woman wears a face mask, as she walks outside San Rafael Hospital, after health authorities decided to suspend outpatient services for three days, due to the involvement of workers and patients after a coranovirus outbreak, according to the press release of the Ministry of Health, in Alajuela, Costa Rica March 9, 2020. REUTERS/Juan Carlos Ulate

A woman wears a face mask, as she walks in front of the San Rafael Hospital, after health authorities decided to suspend outpatient services for three days, due to the involvement of workers and patients after a coranovirus outbreak, according to the press release of the Ministry of Health, in Alajuela, Costa Rica March 9, 2020. REUTERS/Juan Carlos Ulate

A woman wears a face mask, as she walks in front of the San Rafael Hospital, after health authorities decided to suspend outpatient services for three days, due to the involvement of workers and patients after a coranovirus outbreak, according to the press release of the Ministry of Health, in Alajuela, Costa Rica March 9, 2020. REUTERS/Juan Carlos Ulate

A woman checks her cell phone in front of the San Rafael Hospital, after health authorities decided to suspend outpatient services for three days, due to the involvement of workers and patients after a Coranovirus outbreak, according to the press release of the Ministry of Health, in Alajuela, Costa Rica March 9, 2020. REUTERS/Juan Carlos Ulate

Outpatients queue for haemodialysis at the renal unit of the Kenyatta National Hospital in Nairobi, Kenya January 22, 2020. Picture taken January 22, 2020. REUTERS/Njeri Mwangi

British Prime Minister Boris Johnson speaks to outpatient Kathy Power at the East Midlands and East of England Genomic Laboratory Hub, in Addenbrooke's Hospital in Cambridge, Britain October 31, 2019. Alastair Grant/Pool via REUTERS REFILE - CORRECTING LOCATION

Camilla, Duchess of Cornwall holds a balloon, a present for her new-born grandchild, during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

Camilla, Duchess of Cornwall holds a balloon, a present for her new-born grandchild, during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

Camilla, Duchess of Cornwall holds a balloon, a present for her new-born grandchild, during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

Camilla, Duchess of Cornwall holds a balloon, a present for her new-born grandchild, during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

Camilla, Duchess of Cornwall holds a present for her new-born grandchild, during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

Camilla, Duchess of Cornwall holds a balloon, a present for her new-born grandchild, during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

Camilla, Duchess of Cornwall holds a balloon, a present for her new-born grandchild, during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

Deputy medical director Saskia Etzold offers presents to Camilla, Duchess of Cornwall, for her new-born grandchild during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

Deputy medical director Saskia Etzold offers presents to Camilla, Duchess of Cornwall, for her new-born grandchild during her visit to Charite's Violence Protection Outpatient Clinic in Berlin, Germany, May 7, 2019. Ralf Hirschberger/Pool via Reuters

A patient lies on a bed as she recovers at an obstetric fistula repair centre in Maiduguri, Nigeria July 31, 2018. Picture taken July 31, 2018. REUTERS/Afolabi Sotunde

A patient is pushed down a corridor in Frimley Park Hospital near Camberley, Britain, January 4, 2018. REUTERS/Toby Melville

Toronto Blue Jays pitcher Marcus Stroman takes the first Lyft ride in Canada with an outpatient at Sick Kids Hospital and a driver at Lyft launch event in Toronto, Ontario, Canada on December 12, 2017. REUTERS/Alastair Sharp

Toronto Blue Jays pitcher Marcus Stroman takes the first Lyft ride in Canada with an outpatient at Sick Kids Hospital and a driver at Lyft launch event in Toronto, Ontario, Canada on December 12, 2017. REUTERS/Alastair Sharp

A cat is seen in a cage following a surgery at the "Berlioz veterinary clinic" in Nice, France, December 8, 2017. REUTERS/Eric Gaillard

A nurse demonstrates the application of the NARCAN nasal spray medication at a outpatient treatment center in Indiana, Pennsylvania, U.S. August 9, 2017. Picture taken August 9, 2017. REUTERS/Adrees Latif

A box of NARCAN nasal spray is photographed at an outpatient treatment center in Indiana, Pennsylvania, U.S. on August 9, 2017. Picture taken on August 9, 2017. REUTERS/Adrees Latif

A nurse holds NARCAN nasal spray medication at a outpatient treatment center in Indiana, Pennsylvania, U.S. on August 9, 2017. Picture taken on August 9, 2017. REUTERS/Adrees Latif

A sign reads "Drug testing in session," on the bathroom door of an outpatient treatment center in Indiana, Pennsylvania, U.S. on August 9, 2017. Picture taken on August 9, 2017. REUTERS/Adrees Latif

Palestinian patients present their documents as they wait to receive treatment at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Palestinian girl Marah Mokat, who fractured her leg, is carried by her father as she waits for medical checks at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Palestinian boy Mohammed Bahtiti (L), 13, who fractured his leg, waits for medical checks at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY.

Palestinian boy Mohammed Bahtiti, 13, who fractured his leg, waits for medical checks at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Palestinian girl Nour Seyam, 3, who suffers from tonsillitis, is checked by a doctor at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Palestinian girl Marah Mokat, 4 months old, who fractured her leg, is carried by her father as she waits for medical checks at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Palestinian boy Mohammed Bahtiti, 13, who fractured his leg, waits for medical checks at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Palestinian patients present their documents as they wait to receive treatment at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Palestinian girl Nour Seyam, 3, who suffers from tonsillitis, is checked by a doctor at an outpatient clinic at Shifa hospital, Gaza's largest public medical facility, in Gaza City, March 29, 2017. REUTERS/Mohammed Salem SEARCH "GAZA HEALTH" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.