Photo taken on March 31, 2021 shows a view of the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

A volunteer paints red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Volunteers paint red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Volunteers paint red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Volunteers paint red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Volunteers paint red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Photo taken on March 31, 2021 shows the National COVID Memorial Wall in London, Britain. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Photo taken on March 31, 2021 shows messages and red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

A volunteer paints red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

A woman looks at the National COVID Memorial Wall in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Photo taken on March 31, 2021 shows messages and red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Volunteers paint red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

A woman is seen next to the National COVID Memorial Wall in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

Volunteers paint red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]

A volunteer paints red hearts representing the victims who died of COVID-19 on the National COVID Memorial Wall outside St Thomas' Hospital in London, Britain, on March 31, 2021. Bereaved family members and volunteers are in the process of painting hearts along a half-mile wall opposite to the Houses of Parliament in London in remembrance of those who died of COVID-19. Another 4,052 people in Britain tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 4,345,788, according to official figures released Wednesday. [Photo/Xinhua]