treat covid, preventing it from becoming a more serious illness. these antivirals are significant new defences. we haven t had these before, one of these antivirals that has already been approved by our regulator was quite recent. and so it is the first time we have got this type of defence. changing isolation rules this type of defence. changing isolation rules means - this type of defence. changing isolation rules means that - this type of defence. changing isolation rules means that for| this type of defence. changing - isolation rules means that for some, christmas has come early, but this still threatens to be a very challenging festive season, with the new variant spreading fast. dominic hughes, bbc news. our health correspondent anna collinsonjoins me now. what s the science behind reducing quarantine time in england? well, it is a really good question, the government says the way to reduce this disruption we are seeing is by shortening this time from ten days to seven. resear