While the early part of the Omicron wave was driven by infections in younger people, data shows that COVID cases in people over 60 in England have now risen steeply.
According to UK government data, new infections for the under 60s began to rise in early November, but mid December saw a sudden sharp rise in older people.
The rolling case rate in over 60s was 852 on 30 December – the most recent date for which complete data is available – up from 136.4 on 30 November.
While reports have stated that Omicron is a milder variant that causes less severe illness, the older age group are more likely to suffer serious outcomes from COVID – potentially putting further strain on the NHS throughout the winter months.
However, figures also show that 85% of people over 65 have had three doses of the vaccine, reducing the likelihood of them suffering from severe illness.
It comes as England’s chief medical officer Professor Sir Chris Whitty urged people to get jabbed as people in every age band are “significantly protected by vaccination”.
Speaking at a press briefing in Downing Street on Tuesday, Whitty said: “Every age band, being vaccinated, whether it’s previous variants and is likely to be true for this variant, every age band people are significantly protected by vaccination.
“And it is really critical whatever age people are, that they do get vaccinated.”
Watch: Vallance: Omicron cases in older people on rise in London
Whitty added that in terms of reducing hospitalisations, “we are now confident that boosting provides very significant protection and that the one or two vaccines provide some level of protection”.
However, he acknowledged “some hospitals, some areas of the country” will come under “very substantial pressure over the next couple of weeks” with high numbers of staff isolating over infections compounding the typical winter pressures.
Also on Tuesday, Boris Johnson said there is a “good chance” he will not impose fresh restrictions to tackle the massive wave of Omicron cases, as he backed sticking with Plan B measures despite acknowledging parts of the NHS will feel “temporarily overwhelmed”.
The prime minister confirmed he would advocate to his Cabinet today the need to stick with work-from-home guidance, mask-wearing and COVID health passes to “ride out” the wave of infections but warned that anyone who believes the battle against the disease is over is “profoundly wrong”.
He spoke on the day a record 218,724 lab-confirmed COVID cases were announced in England and Scotland – though the figure will have been inflated by delayed reporting over the holiday period.
Johnson accepted the weeks ahead are going to be “challenging” and said “some services will be disrupted by staff absences” as he pledged to “fortify” the NHS to withstand the pressures and protect supply chains.
Under the measures, he said 100,000 “critical workers” including those in transport, policing and food distribution will get lateral flow tests on every working day starting on Monday.
Pressed on how likely he things it is that further restrictions will be needed, Johnson said “it depends to be absolutely frank” on whether the strain first identified in South Africa behaves in a similar way to it has there and “how quickly it blows through”.
“I would say we have a good chance of getting through the Omicron wave without the need for further restrictions and without the need certainly for a lockdown,” he added.
But shadow health secretary Wes Streeting accused Johnson of “complacency” as people struggled to access COVID tests and critical incidents were being declared by hospitals.
He told reporters: “There are serious pressures on the NHS, the prime minister has got to be honest with the country about those pressures and even more importantly set out how he plans to address them.”
Watch: Boris Johnson sticks with Plan B in bid to 'ride out' Omicron without lockdown