Lockdown measures will remain in place until at least March 8, Boris Johnson said as he earmarked that date to begin the reopening of England's schools.
The Prime Minister confirmed that hopes of pupils returning to class after the February half-term have been abandoned as the battle with coronavirus remained "perilous".
Government figures showed a further 1,725 people had died within 28 days of testing positive for Covid-19 as of Wednesday, bringing the UK total to 101,887, while there were a further 25,308 lab-confirmed cases.
The March reopening date is based on progress in vaccinating the most vulnerable groups in society by mid-February and then giving the jab time to take effect.
So far 7,164,387 people have received a first dose of either the Pfizer or AstraZeneca vaccines - a rise of 311,060 on the previous day's figures - although Mr Johnson acknowledged a "sense of frustration" about the patchy nature of the rollout.
The Prime Minister also set out tougher measures to prevent the arrival of new strains of coronavirus into the UK, confirming plans for a 10-day quarantine in hotels for travellers from high-risk countries.
What are the important dates in the lockdown review?
The first date - and potentially the most important - is February 15, reports the Mirror.
This is the date that the UK government has set to have carried out the vaccinations of the 15 million most vulnerable people by.
It is also the beginning of the week which will see the Government kick off its review of the effectiveness of lockdown.
From the week beginning February 22, the Government will set out the result of the review and a publish a timetable for taking the country out of lockdown, but insiders warn that this is dependent on the review results.
The third crucial date is the week beginning March 8, which is when Boris Johnson has said he hopes schools will reopen.
The date has been picked because it will be - ministers hope - three weeks since the last of the four most vulnerable groups have recieved their first dose of the Covid jab, meaning they should have a high level of immunity.
What are the Government going to review in mid February?
The review beginning the week of February 15 will look at three things.
Firstlly, Downing Street has suggested it's by this date that scientific advisors should have sufficient data from the UK and foreign vaccination programme on how effective jabs are at reducing hospitalisations and deaths.
Secondly, they should be able to tell how effective lockdown has been at reducing hospitalisation levels.
And thirdly they will look at the current levels of hospitalisation across the NHS.
Based on this data - and the vaccine programme's ambitious target succeeding they should be able to form a plan to lift lockdown and keep to the schedule to reopen schools.
Boris Johnson told a No10 press conference there must be proof measures are working before lockdown can ease - and “the proof will only become visible in the middle of February.”
Because schools need two weeks’ notice to reopen, he said, “it is sensible now to serve notice that we will not be able to reopen schools immediately after half term on February 22.”
When will schools go back - and will they go back all at once?
Schools in England are currently only open to key workers’ and vulnerable children.
Boris Johnson announced he “hopes” they will start reopening more widely from March 8.
This will be dependent on progress against coronavirus and could be pushed even later.
It’s also unlikely all schools will open to all pupils at once.
Back last summer, Years R, 1 and 6 and secondary school exam years went back first. That may be repeated.
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It’s understood it is unlikely schools would remain shut in one region while opening in another.
But the government does have a ‘contain framework’ which it can use to shut schools in specific council areas with high Covid rates.
What is happening with free school meals?
Currently, parents whose children qualify for Free School Meals can get supermarket vouchers or food parcels worth £15 per child per week.
Boris Johnson confirmed that will continue until kids return to school, be in on March 8 or later.
However, we understand that promise does not include the week of February half-term on February 15.
Instead, kids will need to rely on the Covid Winter Grant Scheme. This is a programme in which councils find and target the most vulnerable kids for help.
However, critics don’t like the Winter Grant Scheme because it isn’t a blanket £15-a-head offer to all kids below a certain level of poverty. And it covers activities and other bills not just food.
What is happening with travel quarantine?
More travel rules have been added on top of the complex maze already in place.
A new rule, announced today, means anyone trying to leave the UK must declare they have a valid reason with their carrier or airline. Those without a valid reason such as work can be sent home from the airport or fined.
In terms of inbound travel there are many different rules.
Anyone arriving in the UK must have a negative test result within 72 hours of their trip.
Everyone must also self-isolate for 10 days, unless they fall under a number of specific exemptions.
On top of this, travel is banned completely from 30 countries with new variants (mostly in southern Africa and South America) to the UK - unless you’re a British or Irish national or have residence rights in the UK.
Until now, British and Irish nationals who’ve been in these 30 countries in the past 10 days could return to the UK and self-isolate in their own homes.
But soon this specific group of people will have to quarantine in a guarded hotel. There is still no date for when this will happen.
A sign points the way for a Covid-19 testing centre at Terminal 5 in at London Heathrow Airport
What will be happening with the vaccine scheme?
Around 7million people in the UK have had a first dose of the Covid vaccine.
The government still hopes to give the top priority groups - all over-70s, NHS and care workers, care home residents and shielders - a first dose by February 15.
It then hopes to give the other priority groups - people aged 50 to 69 and those at risk for health reasons - a first dose by the end of April.
Healthy teachers, police, shop workers and other professions under 50 would then only get a jab in the final stage. But there are mounting calls to bump teachers up the list.
Labour has officially called for teachers to get their first dose in the February half-term, just as vaccines begin being rolled out to the under-70s.
When will we hear about things other than schools reopening?
We should get a rough outline of when other restrictions will be lifted when the Government publishes its lockdown exit plan.
Boris Johnson told MPs today that it will be published the week beginning February 22, meaning we should get an update then.
But there is no guarantee that we will get firm answers on when other things will be allowed to get back to some normality.
What we do know is England should be returning to a tiered lockdown system at some point. What we don't know is when this will happen - or whether the tier rules will look the same as they did before.
