Following announcements earlier in the day of new areas being moved into Tier 4, and some of England’s school reopenings being delayed amid rising virus infection rates, the Prime Minister held a press briefing to warn the UK to “redouble efforts” in the fight against Covid-19. It came as the Deputy Medical Officer painted a very grim picture across the UK of rising cases, stating that the full effects of Christmas household mixing has not yet been felt in the NHS yet.