The European Medicines Agency (EMA) announced on Thursday that cases of the Omicron variant appear to be "mostly mild". However, the agency warned these were preliminary findings and said it was still investigating whether the variant could cause severe disease. Marco Cavaleri, EMA's head of biological health threats and vaccines strategy, said: "Cases appear to be mostly mild, however, we need to gather more evidence to determine whether the spectrum of disease severity caused by omicron is different to that of all the variants that have been circulating so far." The revelation comes a day after Mr Johnson reintroduced mask-wearing in indoor settings, advise to work from home, and plans to roll out vaccine passports.

       READ COVERAGE BELOW...

       Additional reporting by Rachel Hagan