Britain on Monday prepared to start its biggest ever immunisation campaign but health officials warned the drive to inoculate millions against Covid-19 would be a ‘marathon’ stretching well into next year. The AFP reports that the world-first rollout of the Pfizer-BioNTech vaccine is due to start on Tuesday — dubbed ‘V-Day’ by Health Secretary Matt Hancock, who has volunteered to take it live on television to assuage any public doubts over the rapid approval. The vaccine rollout coincides with the end-game of Brexit talks on Britain’s future trading relationship with the European