Britons have been warned that the coming months will be 'challenging' as coronavirus cases show no sign of slowing down.
Downing Street insisted it did not have any immediate plans to bring back restrictions but admitted it would keep a 'close watch' on the situation.
The UK is currently recording nearly 43,000 new Covid cases every day on average with levels of infection now on par with the worst of the second peak in January.
Hospitalisations and deaths remain much lower but there are concerns that even a small rise could push the NHS to the brink this winter when it tries to juggle high levels of flu and the usual seasonal pressures.
Epidemiologist and government adviser Professor Andrew Hayward said the situation was 'concerning' and there was 'huge potential for the NHS to come under a lot of pressure'.
Government data up to Sunday show more than 300,000 confirmed cases reported over the last seven days, a 15% increase on the previous week.
The 852 deaths reported from October 11 to October 17 was 8.5% higher than the figure for the previous seven-day period.
Yesterday the UK reported 45,140 cases of coronavirus, bringing the total number of infections to 8,449.165
The number of Covid deaths in the UK yesterday was 57, down 61 per cent on last Sunday
Figures from the Office for National Statistics on Friday showed coronavirus infection levels in England are getting close to the peak seen at the height of the second wave and are mostly being driven by rates among schoolchildren.
The Prime Minister's official spokesman said: 'We obviously keep very close watch on the latest statistics. We always knew the coming months would be challenging.
'What we are seeing is case rates, hospitalisations and deaths still broadly in line with the modelling as set out a few months back now.
'The vaccination programme will continue to be our first line of defence, along with new treatments, testing and public health advice. But we will obviously keep a close watch on cases.
'But it is thanks to our vaccination programme that we are able to substantially break the link between cases, hospitalisations and deaths.'
The spokesman said the success of the vaccines meant 'we are able to be one of the most open economies in Europe, which is benefiting the public and indeed businesses as well'.
Prof Hayward, a member of the Sage scientific advisory panel, told BBC Radio 4's World At One: 'I
