A dose of a Covid-19 vaccine is prepared ahead of being given to a member of the public, inside a vaccination centre set up at Grim's Dyke Golf Club in north west London on December 26, 2021. - England pressed ahead with its Covid-19 immunisation campaign on Sunday in the race to inoculate as many people possible while the number of cases of the Omicron coronavirus variant soars. (Photo by Niklas HALLE'N / AFP)