A woman walks past graffiti with the words Victory to the NHS on a wall at the Royal Victoria Hospital in West Belfast, Northern Ireland. AP Photo
Margaret Keenan, 90, is applauded by staff as she returns to her ward after becoming the first person in the United Kingdom to receive the Pfizer-BioNtech Covid-19 vaccine at University Hospital, Coventry. EPA
Margaret Keenan receives the vaccine, administered by nurse May Parson. EPA
Margaret Keenan speaks to the media at University Hospital in Coventry. AFP
British Prime Minister Boris Johnson gestures as he speaks to staff at Guy's Hospital in London. AP Photo
Retired nurse Suzanne Medows speaks to race relations campaigner Dr Hari Shukla, 87, and his wife Ranju, before he receives the Pfizer-BioNTech Covid-19 vaccine at the Royal Victoria Infirmary in Newcastle. AP Photo
Sister Joanna Sloan receives the Pfizer-BioNTech Covid-19 vaccine, as the first person in Northern Ireland at the Royal Victoria Hospital, in Belfast. AP Photo
"Bill" William Shakespeare, 81, receives the Pfizer-BioNTech Covid-19 vaccine, at University Hospital, Coventry. AP Photo
Michael Tibbs, 99 is given the Pfizer-BioNtech Covid-19 vaccine at Queen Alexandra Hospital in Portsmouth. Getty Images
Michael Tibbs and his son Philip enjoy a cup of tea after Michael received the Pfizer-BioNtech Covid-19 vaccine at Queen Alexandra Hospital. Getty Images
"I've had my covid vaccination" stickers at the Royal Victoria Infirmary in Newcastle. Getty Images
A nurse holds a phial of the Pfizer-BioNTech Covid-19 vaccine at Guy's Hospital in London. Reuters
Medical personnel prepare to administer the Pfizer-BioNTech Covid-19 vaccine to recipients at a health centre in Cardiff. AFP
A woman walks past graffiti with the words Victory to the NHS on a wall at the Royal Victoria Hospital in West Belfast, Northern Ireland. AP Photo
Margaret Keenan, 90, is applauded by staff as she returns to her ward after becoming the first person in the United Kingdom to receive the Pfizer-BioNtech Covid-19 vaccine at University Hospital, Coventry. EPA
Margaret Keenan receives the vaccine, administered by nurse May Parson. EPA
Margaret Keenan speaks to the media at University Hospital in Coventry. AFP
British Prime Minister Boris Johnson gestures as he speaks to staff at Guy's Hospital in London. AP Photo
Retired nurse Suzanne Medows speaks to race relations campaigner Dr Hari Shukla, 87, and his wife Ranju, before he receives the Pfizer-BioNTech Covid-19 vaccine at the Royal Victoria Infirmary in Newcastle. AP Photo
Sister Joanna Sloan receives the Pfizer-BioNTech Covid-19 vaccine, as the first person in Northern Ireland at the Royal Victoria Hospital, in Belfast. AP Photo
"Bill" William Shakespeare, 81, receives the Pfizer-BioNTech Covid-19 vaccine, at University Hospital, Coventry. AP Photo
Michael Tibbs, 99 is given the Pfizer-BioNtech Covid-19 vaccine at Queen Alexandra Hospital in Portsmouth. Getty Images
Michael Tibbs and his son Philip enjoy a cup of tea after Michael received the Pfizer-BioNtech Covid-19 vaccine at Queen Alexandra Hospital. Getty Images
"I've had my covid vaccination" stickers at the Royal Victoria Infirmary in Newcastle. Getty Images
A nurse holds a phial of the Pfizer-BioNTech Covid-19 vaccine at Guy's Hospital in London. Reuters
Medical personnel prepare to administer the Pfizer-BioNTech Covid-19 vaccine to recipients at a health centre in Cardiff. AFP
A woman walks past graffiti with the words Victory to the NHS on a wall at the Royal Victoria Hospital in West Belfast, Northern Ireland. AP Photo