Employees have been asked to work from home and people have been urged to take more tests amid concerns across the UK that the coronavirus crisis could disrupt Christmas celebrations.
People in England have been advised to take a test before visiting crowded indoor spaces – which could include busy shops or Christmas parties.
And in Northern Ireland people are being urged by Stormont ministers to work from home where possible in a bid to curb cases.
It comes amid a spike of cases across Europe and concerns that the crisis could engulf Christmas celebrations for a second year running.
On Monday Boris Johnson said the Government sees no need to introduce fresh Covid-19 restrictions in England despite rising cases across much of Europe.
Yet the recommendation on lateral flow testing for people without symptoms changed to encourage more people to take a test before entering crowded indoor spaces.
Previously the public was advised to use lateral flow tests twice-weekly.
People are also advised to take a test before visiting a person who is at higher risk of getting seriously ill from Covid-19 and get a PCR test if they have symptoms.
Fresh work from home advice has been issued in Northern Ireland and ministers urged people to limit their social contacts and wear face coverings in crowded or indoor settings.
Deputy First Minister Michelle O’Neill said that measures were the best chance of avoiding further restrictions in the weeks ahead.
Elsewhere, Nicola Sturgeon warned of a “precarious” position in Scotland but stopped short of extending the vaccine passport scheme to more venues.
From Monday a negative lateral flow test will also allow entry to nightclubs and large venues, she said.
Ms Sturgeon told MSPs: “We have taken account of the fact that – although our situation is precarious – cases are currently stable and indeed slightly declining, and we have considered the inevitable impact vaccine certification has on the operation of businesses and concluded that, at this stage, extension would not be proportionate.
“We were also mindful of the need over the coming weeks of getting across the message that it is important to be vaccinated and tested ahead of socialising in any setting – including in homes and shopping centres, for example – not just in those that might be covered by a certification scheme.”
And Welsh health minister Eluned Morgan told a Plenary meeting in the Senedd that Wales was “not out of the woods yet” but said there will be no changes to the rules for another three weeks with the country remaining on Alert Level 0.
Ms Morgan said: “The signs from the continent are not good. A new wave of coronavirus is once again sweeping across Europe and countries all around us are tightening their restrictions.
“None of us want to see restrictions back in place in Wales at Christmas but neither do we want to see people falling ill with Covid at Christmas.
“We need everyone’s help and support to keep the virus under control as we start thinking ahead and planning for Christmas.”
The World Health Organisation (WHO) has warned that Europe is likely to experience more than two million Covid-19 deaths by March as it urged people to take a “vaccine plus” approach to tackling the virus,
The WHO said the European region remains “in the firm grip” of the coronavirus pandemic, with reported daily deaths rising to almost 4,200 a day – double the 2,100 deaths a day at the end of September.
Dr Hans Kluge, WHO regional director for Europe, said: “In order to live with this virus and continue our daily lives, we need to take a ‘vaccine plus’ approach.
“This means getting the standard doses of vaccine, taking a booster if offered, as well as incorporating preventive measures into our normal routines.
“Taken together, wearing a mask, washing hands, ventilating indoor spaces, keeping physical distance and sneezing into your elbow are simple, effective ways of gaining control over the virus and keeping societies going.”
Meanwhile, new estimates from the Office for National Statistics suggest that more than nine in 10 UK adults have antibodies for Covid-19.
And separate ONS figures show that a total of 169,767 deaths have occurred in the UK where Covid-19 was mentioned on the death certificate, the ONS said.