New Covid restrictions could be in place until late March under measures examined by the UK government’s scientific advisers.
The modelling considered measures including a ban on socialising with another household indoors and a return to the rule of six outdoors, in line with the Step 2 restrictions in place in England earlier this year.
A consensus paper published on Christmas Eve by the Scientific Pandemic Influenza Group on Modelling, Operational sub-group (Spi-M-O) said “rapidly enacted Step 2 measures reduce the peak of hospital pressure to about half its level under Plan B only”.
The research by experts from Warwick University looked at imposing Step 2 restrictions on either December 28 or New Year’s Day and keeping them in place until 15 January, 28 January or March 28.
It also included a model examining what impact “non-mandated behaviour change” would have if it reduce mixing by half the amount that Step 2 would achieve.
The Spi-M-O summary of the Warwick modelling said: “A reduction in mixing equivalent to half that of Step 2 results in only a very small reduction in severe outcomes compared to Plan B alone.
“Step 2 has a much larger effect, reducing the number of deaths up to 31st May by 39% (24-54%) if kept in place from December 28 until March 28, and 18% (12-27%) if kept in place until January 15.”
The Warwick modelling has not yet been seen by ministers, who are expected to make a decision early next week – potentially as soon as Monday – on whether extra restrictions are required beffore New Year.
The work was completed before the latest data suggesting the Omicron variant may produce less severe illness than the Delta strain of coronavirus.
Minutes from a meeting of the Scientific Advisory Group for Emergencies (Sage) on 23 December noted “the peak in (hospital) admissions is highly uncertain but, even with a reduction in severity, may be comparable to or higher than previous peaks in the absence of significant behaviour change or further interventions”.
The Sage minutes said “the earlier interventions happen, and the more stringent they are, the more likely they are to be effective”.
Any move to return to the kind of lockdown restrictions in Step 2 this winter would be likely to meet with fierce resistance from Tory backbenchers.
Boris Johnson suffered a revolt by around 100 MPs just to get England’s current Plan B measures approved in the weeks before Christmas.
The risk of another rebellion could encourage him to rely on guidance to reduce socialising rather than new laws, if ministers believe extra measures are required.
Dr Jenny Harries, chief executive of the UK Health Security Agency (UKHSA), said Omicron till poses a “serious threat” despite a “glimmer of hope” in research showing people contracting the virus are less likely to need hospital care.
The UKHSA estimated that someone with Omicron was between 31 and 45 per cent less likely to attend A&E, and 50 per cent less likely to be admitted to hospital, than an individual with the Delta variant.
Asked on BBC Radio 4’s Today programme on Friday whether the research on hospitalisations was enough to downgrade her warning to MPs last week, Dr Harries replied: “There’s a glimmer of Christmas hope in the findings we published yesterday.”
The health chief added: “But it definitely isn’t yet at the point where we could downgrade that serious threat.”