A staff wearing a face mask walks into the Vaccination Centre at ExCel exhibition centre in London, Britain, on Jan. 12, 2021. British Prime Minister Boris Johnson on Monday warned against "false complacency" as the country is seeking to speed up the coronavirus vaccine rollout. According to the prime minister, 2.4 million coronavirus jabs have been administered across Britain. Seven new mass vaccination sites in England opened Monday, as the country races against time to bring the pandemic under control. (Xinhua/Han Yan)