The prime minister has given a Covid briefing from Downing Street
Boris Johnson says the UK needs to "redouble our efforts to contain the virus"
But the PM says he is confident "things will be very much better" by Easter - 5 April
It comes as the UK approves the vaccine developed by the University of Oxford and manufactured by AstraZeneca
And more areas of England are to be placed under tier four restrictions from midnight
The health secretary says three quarters of the population of England is now in tier four
Education Secretary Gavin Williamson has set out how pupils will return to school in England in January
Primary schools in some tier four areas will not open as planned on 4 January
Many secondary school pupils will return later than planned so that mass testing can be set up
The US reports its first known case of highly infectious Covid-19 variant first found in the UK
We're going to leave our live coverage here for today.
You can read all the details from today's announcements in our main story here, find out which tier you're in here and find out how many cases are in your area here.
Today's live page was brought to you by Lauren Turner, Sarah Collerton, Dulcie Lee, Becky Morton, Alex Kleiderman, George Wright, Katie Wright, Emma Lynch and Alice Cuddy.
Thanks for joining us.
Johnson: 'Things will be very much better by Easter'
It's been another very busy day again today, with the coming weeks set to look very different for millions of people across the UK.
Let's take a look at the headlines.
Image source, PA MediaA Covid vaccine from Oxford University and the pharmaceutical company AstraZeneca has been approved for use in the UK by the regulator, the Medicines and Healthcare products Regulatory Agency.
It follows the roll-out of the Pfizer vaccine, which was the first to be approved.
Image source, Getty ImagesAn employee stands in front of cardboard figures placed in empty stands at a ski jumping tournament in Germany
If you're just catching up on today's news, here's a round-up of some of the latest developments from across the world.
The Covid rules for a further 20 million people in England are set to change again. The toughest tier of Covid restrictions will apply in the Midlands, North East, parts of the North West and parts of the South West, among other areas from Thursday.
The rest of the UK is already facing stricter rules from those in force just a few weeks ago.
Our explainer on this has been updated and you can read about the new and existing measures here.
Image source, Getty ImagesMost primary schools will return on 4 January, except in some areas in the south of England where there are particularly high infection rates.
In these areas, vulnerable children and children of key workers will still have in-person learning, but others will study from home until 18 January.
You can find the full list of these areas at the bottom of this article.
Image source, Lydia GuthrieA participant in the Oxford-AstraZeneca coronavirus vaccine trials said being involved felt like being part of an "amazing human endeavour".
Lydia Guthrie was among 500 people who volunteered for the Oxford University research project in April after seeing an advert on social media.
She said she felt "proud" after the vaccine was approved on Wednesday, adding that the research team had "moved mountains".
"Of course I felt nervous" when volunteering, she said, but she believed the risk was small after reading the research information.
"I'm a mum, I've got teenage kids so I didn't want to do anything that would affect my health or put me at risk," she added.
"It felt like a tiny thing I could do to be part of an amazing human endeavour, trying to do something really constructive to support the whole community," she told BBC Breakfast.
Guthrie said none of the participants know if they were given the Covid-19 vaccine or not during the trials.
Image source, Getty ImagesPeople travelling from Britain to Sweden will need to show a negative coronavirus test result before entering the country, the Swedish government has said.
The measure will come into force on 1 January and will not apply to Swedish citizens, Home Affairs Minister Mikael Damberg told a press conference.
The test must have been completed a maximum of 72 hours before arrival in Sweden.
It comes as the UK grapples with a new, more contagious coronavirus strain.
Image source, Getty ImagesUK internet use more than doubled in 2020, as people stayed home during the coronavirus pandemic.
Boxing Day was the busiest day for broadband users, according to data from Openreach, which runs much of the UK's broadband network.
A mix of video calls to get in touch with family and friends, as well as TV streaming and gaming downloads were contributing factors to the 26 December record, it said, when large parts of the country were under tight coronavirus restrictions.
The year's second-busiest day was 14 November, as Amazon Prime broadcast two live rugby matches. Openreach said usage surged just before kick-off.
Online gaming also had a big impact on the UK's broadband consumption, with many of the major data spikes focused around updates to popular PlayStation, PC and Xbox games - including Call of Duty and Fortnite.
Alexey Ilin
BBC Russian, Moscow
Image source, Getty ImagesRussian Health Minister Mikhail Murashko has announced that from January 2021 all Russians who have been vaccinated will receive a so-called “vaccine passport”.
The document will be available through the government’s official portal and might in time be used to carry information about other vaccinations.
Moscow city authorities say owners of “vaccine passports” will see real benefits. For example, those eligible for free travel on city’s public transport (students, under 18s and OAPs) who have been vaccinated will have their free travel cards unblocked.
So far, Russians can be vaccinated against Covid-19 only with the country’s own Sputnik V vaccine, developed by the Gamaleya Research Centre.
Alexander Ginzburg, the director of Gamaleya, said that introducing this type of document was the right thing to do.
“Covid passports need to be introduced at the start of the vaccination campaign, so that every person had proof of having had the jab.”
Kirill Dmitriev who heads Russia’s Direct Investment Fund, a state finance body behind Gamaleya, believes in the new year vaccine passports will become common not only in Russia but all over the world.
Russia started a mass vaccination campaign in early December.
Some scientists have expressed scepticism towards Sputnik V. There has been no rush among Russians to get the jab.
Russia’s official death toll from Covid-19 is currently 56,426, with many believing the figure is significantly underestimated.
Speaking at the Downing Street press conference earlier, Prof Stephen Powis, NHS England's national medical director, urged people to stay at home and not mix with others for New Year's Eve.
"Covid loves a crowd, so please leave the parties for later in the year," he said.
The press conference has finished. Here's a round-up of the key points:
Charlie Cooper at Politico also asked Prof Van-Tam what the latest science shows on whether the vaccine will be effective on the new virus variants.
Prof Van-Tam says both the UK strain and South African strain are either in, or on their way to, a government laboratory at Porton Down "to be assessed by the expert virologists to check that the AstraZeneca vaccine will still be effective".
He said he understands that Pfizer is conducting very similar experiments.
"That isn't unfortunately work that takes 12 hours in the lab. It takes more like 12-14 days, because you have to take the virus and grow it up live," he says.
"So it will be a few more days, potentially a couple of weeks, before our scientists can give us a solid steer on that."
He added that if there were an impact on the vaccine effectiveness, he would expect it to be a marginal degradation rather than "we've lost the lot".
"You would need very, very substantial mutations indeed to completely outwit these vaccines altogether," he says.
For the last question, Charlie Cooper from Politico asked the prime minister what the rationale was behind sticking with the tier system - rather than going for a full national lockdown until the vaccines are rolled out to the vulnerable.
In response, Mr Johnson said: "Look, I'm not going to hide it from you, that obviously was an option we considered intensively.
"But on the whole we thought, given the uncertainties that we still face, the impact of the tier four which is still a bit of an open question it would be fair to say... we thought it right to continue with the tiering, particularly since you still have quite a regional differentiation."
He says it also seemed to be the "fairest" way to continue, but adds "we're going to keep reviewing this".
The press conference has come to an end - but we'll bring you what we heard from the final questions.
Prof Jonathan Van-Tam was asked how concerned he is about failed inoculations due to the rising infection rate.
He said there will unfortunately always be people who have been exposed to an infectious disease who are then vaccinated - but not in time for it to have the required effect to give them immunity before the disease takes hold.
He adds that there will potentially be more patients like this in a situation where the disease levels are very high.
Another question from Sky News' Sam Coates, who asks if someone has the vaccine, if they can see their grandchildren as soon as the second dose reaches effectiveness.
Prof-Van Tam says the answer to whether "after the second dose of your vaccine it's OK to behave with wild abandon and go off to the bingo halls" depends on whether the vaccine impacts transmission of the virus.
"We don't know if the vaccines will reduce transmission yet. We definitely will be looking at that," he says.
"Even if you're vaccinated, I can assure you that it's very likely you'll be protected from severe illness. But I can't give you the assurance that you won't still pose a hazard to others through transmitting the virus.
"We have to just be patient on this point, give it another two or three months and then ask me that question again."
Charlotte Ivers from Talk Radio asks if the prime minister could ever envisage a 24/7 rollout of the vaccine.
Boris Johnson says "people are working round the clock" to get the vaccine rolled out but "the rate limiting factor is supply and not distribution”.
Prof Van-Tam adds that "we must go as fast as the speed of supplies” and that there shouldn't be supplies of the vaccine waiting to go out.
Sam Coates, from Sky News, asks if you're a parent of a primary child in a tier four area, are you still legally obliged to send them to school if you're worried about infection rates.
The prime minister says: "[The] message for all parents, except in the school areas which have been specifically identified as being where the epidemic is really surging the most... is schools are safe.
"The problem is not the schools... the issue is the spread from the mixing of households that naturally takes place in schools.
"That's what we're trying to combat in the very high infection rate areas."
Unless your school is identified as being in one of those areas, which are not necessarily all schools in tier four, you should send your children to school, the prime minister says.
Cameron in Buckinghamshire, a member of the public, asks whether tier four restrictions could be in place until the spring.
Boris Johnson says the government wants to get areas out of tier four "as fast as we can" but the spread of the new variant "simply doesn’t give us the scope to do that".
However he says there will become a point where progress with a vaccine means there will be different options.
The prime minister adds that "we are confident that things will be very, very much better" by 5 April - Easter Monday.
He says "obviously we will try and bring that date forward as fast as we can" and "that’s why the vaccine roll-out programme is so important".
BBC medical correspondent Fergus Walsh asks the prime minister how many people will be immunised each week - "because surely it needs to be in the millions".
Mr Johnson says: "The best answer I can give at the moment is we will have tens of millions of doses by the end of March. We're working to get the programme going as fast we can.
"I don't want to give you specific numbers at the moment, but I can tell you that we are shifting heaven and earth to roll them out as fast as we can."
Prof Van-Tam adds that it's "probably not the best idea" to look at December and how the NHS vaccination programme has started so far with the Pfizer vaccine, and to overlay that with "kitchen-table mathematics" as to how that'll scale up from January to March.