Photo taken on Dec. 23, 2020 shows the London Eye in London, Britain. British Health Secretary Matt Hancock on Wednesday announced that more areas of the East and South East of England will be put into Tier Four restrictions, the highest level, while revealing that two cases of another new variant of the novel coronavirus have been identified in Britain. (Xinhua/Han Yan)

An ambulance passes by the Christmas tree outside the Houses of Parliament in London, Britain, on Dec. 23, 2020. British Health Secretary Matt Hancock on Wednesday announced that more areas of the East and South East of England will be put into Tier Four restrictions, the highest level, while revealing that two cases of another new variant of the novel coronavirus have been identified in Britain. (Xinhua/Han Yan)

Vehicles drive past buildings along the River Thames in London, Britain, on Dec. 23, 2020. British Health Secretary Matt Hancock on Wednesday announced that more areas of the East and South East of England will be put into Tier Four restrictions, the highest level, while revealing that two cases of another new variant of the novel coronavirus have been identified in Britain. (Xinhua/Han Yan)

A double decker bus drives past the Westminster Abbey in London, Britain, on Dec. 23, 2020. British Health Secretary Matt Hancock on Wednesday announced that more areas of the East and South East of England will be put into Tier Four restrictions, the highest level, while revealing that two cases of another new variant of the novel coronavirus have been identified in Britain. (Xinhua/Han Yan)

Pedestrian and vehicles are seen on Westminster Bridge in London, Britain, on Dec. 23, 2020. British Health Secretary Matt Hancock on Wednesday announced that more areas of the East and South East of England will be put into Tier Four restrictions, the highest level, while revealing that two cases of another new variant of the novel coronavirus have been identified in Britain. (Xinhua/Han Yan)

A man wearing a face mask walks along the Westminster Bridge in London, Britain, on Dec. 23, 2020. British Health Secretary Matt Hancock on Wednesday announced that more areas of the East and South East of England will be put into Tier Four restrictions, the highest level, while revealing that two cases of another new variant of the novel coronavirus have been identified in Britain. (Xinhua/Han Yan)

Vehicles drive past an underground station in London, Britain on Dec. 23, 2020. British Health Secretary Matt Hancock on Wednesday announced that more areas of the East and South East of England will be put into Tier Four restrictions, the highest level, while revealing that two cases of another new variant of the novel coronavirus have been identified in Britain. (Xinhua/Han Yan)