There have been more than 3.5 million confirmed cases of coronavirus in the UK and more than 100,000 people have died, government figures show.
However, these figures include only people who have died within 28 days of testing positive for coronavirus.
Almost seven million people have had their first dose of a coronavirus vaccine.
Find out how the pandemic has affected your area and how it compares with the national average:
Deaths reach 100,000
The government announced 1,631 deaths within 28 days of a positive test on Tuesday, taking the overall total to just over 100,000.
More people have now died with coronavirus in the second wave than the first.
Prime Minister Boris Johnson said he was "deeply sorry" for all the lives lost and promised the nation would "come together" to honour the dead once the crisis was over.
Of the deaths announced on Tuesday, 1,520 were in England, 87 in Scotland, 16 in Northern Ireland and eight in Wales.
Chief medical officer Professor Chris Whitty said the number of deaths would come down "relatively slowly" over the next two weeks.
The average number of daily deaths began to rise again in September, following the first peak in spring last year.
Rules were amended over the summer to include deaths in the coronavirus total only if they occurred within 28 days of a positive test. Previously in England, all deaths after a positive test were included.
England has seen the majority of UK deaths from Covid-19. Using the 28-day cut-off, there have been about 88,000.
Death certificate mentions pass 100,000
When looking at the overall death toll from coronavirus, official figures count deaths in three different ways, each giving a slightly different number.
First, government figures count people who died within 28 days of testing positive for coronavirus - and that total has now reached 100,000.
Second, ONS figures include all deaths where coronavirus was mentioned on the death certificate, even if the person had not been tested for the virus. This figure is nearly 104,000 deaths, to 15 January.
The third measure counts all deaths over and above the usual number at the time of year - that figure was more than 99,000 by 15 January.
In total there were 20,019 deaths registered in the week to 15 January, that's about 28% above the "normal" level for the time of year.
Of that figure, 7,776 were deaths related to coronavirus - the third highest total of the pandemic.
There have now been more deaths involving Covid than 'excess' deaths, which means non-Covid deaths must be below usual levels.
This could be because of a milder flu season - resulting from less travel and more social distancing - and because some people who might have died for other reasons had there been no pandemic, died of Covid.
The number of cases reached record levels in early January, partly driven by a new variant of the virus thought to be much more easily transmissible than other strains.
However daily reported cases, on average, now appear to be declining.
A further 20,089 confirmed cases across the UK were announced by the government on Tuesday.
It is thought the infection rate was much higher than was evident from the reported number of cases during the first peak in spring last year. Testing capacity was too limited to detect the true number of daily cases.
The darker orange and red areas on the map below show the areas currently seeing the highest number of cases per 100,000 people.
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UK vaccine rollout on track
Latest government figures show that more than 6.8 million people in the UK have now received a first dose of a vaccine, and more than 470,000 people have had a second.
Health Secretary Matt Hancock says almost four in five of the UK's over 80s have now had the vaccine.
About 380,000 doses need to be given each day if the government is to reach its target of vaccinating the 15 million most vulnerable people by the middle of February.
The current seven-day average is almost 370,000.
In total, more than 5.9 million people in England have had one vaccine dose. In Scotland, 437,000 people have had their first dose, while the figure is around 289,000 in Wales and 163,000 in Northern Ireland.
People in England aged 70 and over, as well as those listed as clinically extremely vulnerable, are expected to be the next group to receive vaccines.
The government is aiming to offer all UK adults a vaccine by September.
Hospitals under severe pressure
There are now just under 38,000 people with coronavirus in hospital in the UK - almost double the number in the spring peak.
Health Secretary Matt Hancock says staff on Covid wards are "flat out and stretched to the limit".
London, the South East, the East of England and Midlands have seen the biggest numbers in recent weeks.
But all nations and regions now have more patients in hospital than during the first wave in spring.
UK nations under lockdown
Lockdowns are in place across the UK, with schools closed to most pupils.
People have been told to stay at home, other than for limited purposes such as essential food shopping, medical appointments and work which cannot be performed in the home.
The lockdown in England will be reviewed on 15 February.
The restrictions in Wales are due to be reviewed on 29 January.
In Scotland, restrictions have been extended until at least the middle of February.
In Northern Ireland, the lockdown has been extended through to 5 March.
What is the R number in the UK?
The "R number" is the average number of people an infected person will pass the disease on to.
If R is below one, then the number of people contracting the disease will fall; if it is above one, the number will grow.
The government's current estimate for the R number across the whole of the UK is 0.8 to 1.0, which means the outbreak could now be shrinking.
The estimate for England is 0.8 to 1.0, Scotland is 0.8 to 1.1, Wales is 0.8 to 1.1 and in Northern Ireland it is 0.65 to 0.85.
The government has said in the past that the R number is one of the most important factors in making policy decisions. On Friday, it dipped below 1.0 for the first time since mid-December.