The UK has launched its biggest ever vaccination programme, aimed at protecting tens of millions of people from Covid-19 within months.
In a race against a faster-spreading variant of coronavirus, ministers have pinned their hopes of ending a third national lockdown on protecting the most vulnerable groups by spring.
But there are huge challenges, not least the unprecedented scale and supply demands but also the need for rigorous safety checks and deep-freeze storage as well as establishing enough vaccination centres and recruiting enough vaccinators.
How is the rollout going?
The government aims to offer vaccines to 15 million people – those aged 70 and over, healthcare workers and people required to shield – by mid-February and millions more people aged 50 and over and other priority groups by spring.
They are thought to represent 90-99% of those at risk of dying from Covid-19.
In order to hit the mid-February target, the UK’s National Health Service (NHS) needs to administer about 380,000 vaccine doses each day.
The current seven-day average achieved just over 353,000, so the first phase of the programme is almost on track. However the number of daily jabs administered this week has dropped compared with last.
The campaign to reach as many people as possible as quickly as possible was boosted by a shift in policy in early January – to prioritise the first dose of either vaccine, with a second dose up to 12 weeks later, a bigger gap than originally planned.
Overall, more than 7.4 million people have now received a first dose of a vaccine, and more than 470,000 people have had a second.
This progress means the UK continues to be among the countries with the highest vaccination rates globally.
But within the UK, there is some regional variation – especially between the nations.
Within England, the gap between the top and bottom areas has narrowed in the last week.
Suffolk and North East Essex – an area where only 36% of those 80 and over had been vaccinated – has almost doubled the number to 71%.
Gloucestershire has the highest proportion of those 80 and over to receive a vaccine – at 91%. The lowest four areas are all in London where overall 65% of those 80 and over have had the jab.
The speedy rollout of the vaccine to all vulnerable people is seen as critical to reducing the pandemic’s death toll and relieving pressure on the NHS.
The health secretary has told MPs that supply of the vaccine must be fairly distributed across the country, with everyone in the top four priority groups receiving an offer of a vaccine by 15 February.
After the first four priority groups receive their jabs, the programme will move onto people aged 50 and over and those with underlying health conditions.
By autumn, the rest of the adult population, another 21 million people, will be offered a vaccine. Teachers, transport workers, supermarket workers and the military could be prioritised.
Where are the vaccines coming from?
The UK is currently receiving doses of two vaccines approved by the medicine regulator.