Coronavirus hospital and intensive care are rising among over-65s, government figures show.
Data discussed by Boris Johnson and top government scientists at Wednesday’s coronavirus briefing showed hospital admissions rising sharply for over-65s since the end of August.
The number of people being admitted into intensive care also rose sharply from mid-September among older age groups.
While the numbers remained relatively small, the rate of increase will be pored over by ministers as they make decisions on Covid-19.
The number of admissions to intensive care rose particularly in London, the Midlands, Yorkshire and the north-east and the north-west, the figures showed.
The prime minister urged people to continue following Covid-19 restrictions or potentially face “further measures”.
“If we put in the work together now then we give ourselves the best possible chance of avoiding that outcome and avoiding further measures,” he said.
“I know some people will think we should give up and let the virus take its course despite the huge loss of life that would potentially entail.
“I have to say I profoundly disagree. I don’t think that is what the British people want. I don’t think they want to throw in the sponge. They want to fight and defeat this virus and that is what we are going to do.”
Government chief scientific adviser Sir Patrick Vallance said: “Numbers of cases are going up, hospitalisations are going up, ICU is going up and unfortunately very sadly so are deaths.
“That means this is heading in the wrong direction, there is no cause for complacency here at all.”
Vallance also warned it would be “wrong” to think that the problem was only in areas under local lockdowns.
“It is worst in certain areas but there is evidence of spread everywhere,” he said.
Chief medical officer Chris Whitty said the number of infections was doubling slower than in March, when the country locked down to contain the spread and the virus was doubling every three to four days.
“One of the problems we had in the first wave was I think we initially underestimated how fast the doubling was occurring at that stage,” he said.
“It’s very important we don’t do that a second time because once exponential growth starts... things go very quickly.”
Whitty added: “The small number of deaths now shouldn’t reassure us that we won’t be, in relatively short order, in quite difficult places, certainly in regions where we are seeing significant growth at the moment, where pressure on the NHS could happen sooner rather than later if we can’t get on top of it really quite fast.”