Professor Neil Ferguson, an epidemiologist at Imperial College London, said on Tuesday that infections in the capital could decrease in the coming days.
He told BBC Radio 4’s Today programme: “I think I’m cautiously optimistic that infection rates in London in that key 18-50 age group, which has been driving the Omicron epidemic, may possibly have plateaued.
“It’s too early to say whether they’re going down yet.
“I would say that with an epidemic which has been spreading so quickly and reaching such high numbers, it can’t sustain those numbers forever, so we would expect to see case numbers start to come down in the next week, maybe already coming down in London, but in other regions a week to three weeks.
Watch: Boris Johnson says no new restrictions despite Omicron wave
“Whether they then drop precipitously or we see a pattern a bit like we saw with Delta back in July – of an initial drop and then quite a high plateau – remains to be seen, it’s just too difficult to interpret current mixing trends and what the effect of open schools again will be.”
His comments echoed those of other scientists.
On Monday, Professor Tim Spector, who leads the ZOE COVID symptoms study app, tweeted: “With COVID cases in London now decreasing and UK slowing - it is great to see no real change in COVID deaths over last month.”
Paul Hunter, professor in medicine at the University of East Anglia, said the latest ZOE app data suggested that “infections in London did peak a day or so before Christmas and are probably peaking nationally about now”.
In London, 314 COVID-19 patients were admitted to hospital on 1 January, a down from the 437 admitted last Monday.
A total of 157,758 coronavirus cases were recorded in England and Scotland on Monday, according to the latest government figures.
Data from Wales and Northern Ireland will be updated after the Christmas period.
The UK reported a record high of 189,846 COVID-19 cases on New Year’s Eve.
Education secretary and former vaccines minister Nadhim Zahawi told Sky News on Monday: “The number of people in hospital with coronavirus has begun to rise in the over-fifties, which we are concerned about.
“But on the whole actually the number of people in ICU has come down, which is good news."
On Tuesday, Matthew Taylor, chief executive of the NHS Confederation, said hospital admissions seem to have “perhaps plateaued in London or there may be a second peak after the new year now, but it’s rising across the rest of Britain”.
He told Times Radio that for many hospitals “the most pressing element of all” was the number of staff who are absent due to coronavirus.
He said that even without the spread of COVID-19, the NHS is 100,000 staff short.
Before Christmas, NHS staff absences in London doubled in the space of a week.
At least six hospital trusts have declared critical incidents – where priority services may be under threat.
Prime minister Boris Johnson said on Monday that he would “make sure that we look after our NHS any way that we can”.
Watch: A further 157,758 COVID cases reported in England and Scotland