coronavirus tier system could ruin family Christmases. A government expert warned that the lowest tier was less effective at reducing, recommending that they should be tightened until a Covid-19 vaccine can be implemented.Dr Susan Hopkins, of Public Health England, told a Downing Street briefing that tier 1 had shown "very little effect".This could mean that there is a ban on households mixing indoors after the national lockdown ends, jeopardising hopes families will be able to spend Christmas with their loved ones unless they live together.Dr Hopkins said the higher tiers appeared to be working well before the second lockdown was introduced on November 5.