LONDON (Reuters) - England will need five extra days of lockdown measures to stop COVID-19 infections spreading for each day they are relaxed over the Christmas period to allow people to see their families, a senior government health adviser has warned. Susan Hopkins, deputy director of the national infections service at Public Health England, told reporters on Wednesday that the advice from the Scientific Advisory Group for Emergencies would mean two days of tighter restrictions.However, Public Health England, the government agency responsible for responding to public health emergencies, later clarified that Hopkins had misspoken, and that “for every one day of relaxation, five days of tighter restrictions would potentially be needed.” Prime Minister Boris Johnson has vowed to ease lockdown restrictions on Dec 2 after a month-long lockdown imposed to stop a second wave of infections threatening the health service. He said two weeks ago that he hoped that Christmas could be as normal as possible.