A medical worker prepares a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical worker prepares a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical worker prepares a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical staff member receives a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical staff member receives a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical staff member receives a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical staff member receives a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

Medical team workers are seen near a placard reading "I am in favor of the COVID-19 vaccine" at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A person waits near a placard reading "I am in favor of the COVID-19 vaccine" after receiving a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A person waits near a placard reading "I am in favor of the COVID-19 vaccine" after receiving a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A person waits near a placard reading "I am in favor of the COVID-19 vaccine" after receiving a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical worker prepares a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical worker prepares a dose of AstraZeneca's COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

A medical worker prepares a dose of AstraZeneca COVID-19 vaccine at the Neurological and Functional Rehabilitation Centre of the CHU hospital, amid the spread of the coronavirus disease (COVID-19), in Fraiture, Belgium February 12, 2021. REUTERS/Yves Herman 

Belgian Jean-Pierre Daniels, 48, who spent five weeks in a coma after suffering from the coronavirus disease (COVID-19), and who is technician at the Neurological and Functional Rehabilitation Centre of the CHU hospital in Fraiture, exercises for a last time before leaving the center where he stayed for only one week in rehabilitation as a patient, before returning home in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Louis Varetto 68, who spent weeks in a coma at the intensive care unit after suffering from the coronavirus disease (COVID-19), is helped by a medical staff member during rehabilitation exercises at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Louis Varetto 68, who spent weeks in a coma at the intensive care unit after suffering from the coronavirus disease (COVID-19), is helped by a medical staff member during rehabilitation exercises at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Jean-Pierre Daniels, 48, who spent five weeks in a coma after suffering from the coronavirus disease (COVID-19), and who is technician at the Neurological and Functional Rehabilitation Centre of the CHU hospital in Fraiture, exercises for a last time before leaving the center where he stayed for only one week in rehabilitation as a patient, before returning home in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Louis Varetto 68, who spent weeks in a coma at the intensive care unit after suffering from the coronavirus disease (COVID-19), is helped by a medical staff member at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Louis Varetto 68, who spent weeks in a coma at the intensive care unit after suffering from the coronavirus disease (COVID-19), is helped by a medical staff member at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Louis Varetto 68, who spent weeks in a coma at the intensive care unit after suffering from the coronavirus disease (COVID-19), is helped by a medical staff member at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

A patient who spent several weeks in a coma after suffering from the coronavirus disease (COVID-19), exercises at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman TPX IMAGES OF THE DAY 

Belgian David Collignon, 32 who spent 16 days in a coma after suffered from the coronavirus disease (COVID-19), exercises at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

A patient who spent several weeks in a coma after suffered from the coronavirus disease (COVID-19), exercises at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

A patient who spent several weeks in a coma after suffered from the coronavirus disease (COVID-19), exercises at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Jean-Pierre Daniels, 48, who spent five weeks in a coma after suffering from the coronavirus disease (COVID-19), and who is technician at the Neurological and Functional Rehabilitation Centre of the CHU hospital in Fraiture, leaves the center where he stayed for only one week in rehabilitation as a patient, before returning home in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Jean-Pierre Daniels, 48, who spent five weeks in a coma after suffering from the coronavirus disease (COVID-19), and who is technician at the Neurological and Functional Rehabilitation Centre of the CHU hospital in Fraiture, is applauded by his colleagues, before leaving the center where he stayed for only one week in rehabilitation as a patient, before returning home in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Jean-Pierre Daniels, 48, who spent five weeks in a coma after suffering from the coronavirus disease (COVID-19), and who is technician at the Neurological and Functional Rehabilitation Centre of the CHU hospital in Fraiture, is applauded by his colleagues, before leaving the center where he stayed for only one week in rehabilitation as a patient, before returning home in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Jean-Pierre Daniels, 48, who spent five weeks in a coma after suffering from the coronavirus disease (COVID-19), and who is technician at the Neurological and Functional Rehabilitation Centre of the CHU hospital in Fraiture, is applauded by his colleagues, before leaving the center where he stayed for only one week in rehabilitation as a patient, before returning home in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian Jean-Pierre Daniels, 48, who spent five weeks in a coma after suffering from the coronavirus disease (COVID-19), and who is technician at the Neurological and Functional Rehabilitation Centre of the CHU hospital in Fraiture, is applauded by his colleagues, before leaving the center where he stayed for only one week in rehabilitation as a patient, before returning home in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Louis Varetto 68, who spent weeks in a coma at the intensive care unit after suffering from the coronavirus disease (COVID-19), exercises waves from through a window, at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

A patient who spent weeks in intensive care after suffering from the coronavirus disease (COVID-19), lies in bed, at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

A patient who spent weeks in intensive care after suffering from the coronavirus disease (COVID-19), exercises with a medical staff, at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

A patient who spent weeks in intensive care after suffering from the coronavirus disease (COVID-19), exercises with a medical staff, at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon, 32 who spent 16 days in a coma after suffered from the coronavirus disease (COVID-19), talks with doctor Daniel Guillaume, at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon, 32 who spent 16 days in a coma after suffering from the coronavirus disease (COVID-19), exercises with a medical staff at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon, 32 who spent 16 days in a coma after suffered from the coronavirus disease (COVID-19), exercises with a medical staff at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon, 32 who spent 16 days in a coma after suffered from the coronavirus disease (COVID-19), exercises with a medical staff (not pictured) at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon,32 who spent 16 days in a coma after suffering from the coronavirus disease (COVID-19), exercises with a medical staff at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon,32 who spent 16 days in a coma after suffered from the coronavirus disease (COVID-19), exercises with a medical staff at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon,32 who spent 16 days in a coma after suffering from the coronavirus disease (COVID-19), exercises with a medical staff at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon,32 who spent 16 days in a coma after suffering from the coronavirus disease (COVID-19), exercises with a medical staff at the Neurological and Functional Rehabilitation Centre of the CHU hospital, in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon, 32, who spent 16 days in a coma, helps his mother Marie-Claire Leornard, 57, who was in the intensive care for one month, as they reside together, but in separate rooms, in the Neurological and Functional Rehabilitation Centre of the CHU hospital, after both suffered from the coronavirus disease (COVID-19), in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Belgian David Collignon, 32, who spent 16 days in a coma, helps his mother Marie-Claire Leornard, 57, who was in the intensive care for one month, as they reside together, but in separate rooms, in the Neurological and Functional Rehabilitation Centre of the CHU hospital, after both suffered from the coronavirus disease (COVID-19), in Fraiture, Belgium May 8, 2020. REUTERS/Yves Herman 

Neurological follow-up care Chief Beatrice Davenne, occupational therapist Guillome Arminot and physiotherapist Adrien choose a splint for a patient at the post COVID-19 unit at the Robert Ballanger hospital in Aulnay-sous-Bois near Paris during the outbreak of the coronavirus disease in France, April 30, 2020. Seine-Saint-Denis, a mainly working class and multiracial suburb, was already lacking doctors and resources before the coronavirus crisis and has seen a bigger spike in mortality than neighbouring Paris. But despite being understaffed, teams at Robert Ballanger hospital reorganized to prioritize emergency health and have worked long hours, giving everything to fight the virus. Picture taken April 30, 2020. REUTERS/Gonzalo Fuentes 

Nurses Rita and Mary pose in front of balloons outside the National Hospital for Neurology and Neurosurgery, as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, April 25, 2020. REUTERS/Simon Dawson 

A muslim woman walks past balloons outside the National Hospital for Neurology and Neurosurgery, as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, April 25, 2020. REUTERS/Simon Dawson TPX IMAGES OF THE DAY 

Co-organisers of a rainbow flower display Joanna Franks and Cheryl Lobo, both consultant breast and oncoplastic surgeons and Sohier Elneir, Urogynaecology and Uro-neurology consultant, pose for a picture in front of it, during the outbreak of the coronavirus disease (COVID-19), outside the University College Hospital in London, Britain, April 23, 2020. REUTERS/John Sibley 

German President Frank-Walter Steinmeier, and his wife Elke Budenbender, listen to Lori Lebson, Medical Director of Neurology for US Medical Affairs, during a tour at MilliporeSigma Life Science Center in Burlington, Massachusetts, U.S., November 1, 2019. REUTERS/Mary Schwalm 

Karl Max Einhaeupl, Chairman of the Charite hospital, and Kai-Uwe Eckardt, Director of the clinic for Neurology and Internal Medicine, address a news conference about treatment of Pyotr Verzilov, publisher of a Russian online news outlet and affiliated with the anti-Kremlin band Pussy Riot, at the Charite hospital in Berlin, Germany September 18, 2018. REUTERS/Fabrizio Bensch 

Kai-Uwe Eckardt, Director of the clinic for Neurology and Internal Medicine, addresses a news conference about treatment of Pyotr Verzilov, publisher of a Russian online news outlet and affiliated with the anti-Kremlin band Pussy Riot, at the Charite hospital in Berlin, Germany September 18, 2018. REUTERS/Fabrizio Bensch 

Kai-Uwe Eckardt, Director of the clinic for Neurology and Internal Medicine, addresses a news conference about treatment of Pyotr Verzilov, publisher of a Russian online news outlet and affiliated with the anti-Kremlin band Pussy Riot, at the Charite hospital in Berlin, Germany September 18, 2018. REUTERS/Fabrizio Bensch 

Karl Max Einhaeupl, Chairman of the Charite hospital, and Kai-Uwe Eckardt, Director of the clinic for Neurology and Internal Medicine, address a news conference about treatment of Pyotr Verzilov, publisher of a Russian online news outlet and affiliated with the anti-Kremlin band Pussy Riot, at the Charite hospital in Berlin, Germany September 18, 2018. REUTERS/Fabrizio Bensch 

A cat receives treatment at Shanghai TCM (Traditional Chinese Medicine) Neurology and Acupuncture Animal Health Center, which specialises in acupuncture and moxibustion treatment for animals, in Shanghai, China, August 9, 2017. REUTERS/Aly Song SEARCH "ACUPUNCTURE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A dog receives treatment at Shanghai TCM (Traditional Chinese Medicine) Neurology and Acupuncture Animal Health Center, which specialises in acupuncture and moxibustion treatment for animals, in Shanghai, China, August 16, 2017. REUTERS/Aly Song SEARCH "ACUPUNCTURE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A cat receives treatment at Shanghai TCM (Traditional Chinese Medicine) Neurology and Acupuncture Animal Health Center, which specialises in acupuncture and moxibustion treatment for animals, in Shanghai, China, August 16, 2017. REUTERS/Aly Song SEARCH "ACUPUNCTURE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A dog receives treatment at Shanghai TCM (Traditional Chinese Medicine) Neurology and Acupuncture Animal Health Center, which specialises in acupuncture and moxibustion treatment for animals, in Shanghai, China, August 10, 2017. REUTERS/Aly Song SEARCH "ACUPUNCTURE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A dog is carried in a pram by its owner after receiving treatment at Shanghai TCM (Traditional Chinese Medicine) Neurology and Acupuncture Animal Health Center, which specialises in acupuncture and moxibustion treatment for animals, in Shanghai, China, August 16, 2017. REUTERS/Aly Song SEARCH "ACUPUNCTURE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A cat is carried by its owner after receiving treatment at Shanghai TCM (Traditional Chinese Medicine) Neurology and Acupuncture Animal Health Center, which specialises in acupuncture and moxibustion treatment for animals, in Shanghai, China, August 16, 2017. REUTERS/Aly Song SEARCH "ACUPUNCTURE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Acupuncture needles are seen at Shanghai TCM (Traditional Chinese Medicine) Neurology and Acupuncture Animal Health Center, which specialises in acupuncture and moxibustion treatment for animals, in Shanghai, China August 16, 2017. REUTERS/Aly Song SEARCH "ACUPUNCTURE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.