More than 15 million people in the UK have received a first dose of a coronavirus jab, the prime minister has said.
Boris Johnson released a video in which he called it an "extraordinary feat".
"In England, I can tell you we have now offered jabs to everyone in the first four priority groups, the people most likely to be severely ill from coronavirus, hitting the first target we set ourselves," said Mr Johnson.
While the 15 million figure was a key indicator of the target he set on 4 January, it isn't yet known whether the aim to offer a first jab to everyone in all UK nations from the initial four groups has been met.
The first four target groups are:
• Care home residents and their carers
• Frontline health and social care workers
• Everyone 70 and older
• Clinically extremely vulnerable people
Mr Johnson said the vaccines had been "delivered by the most extraordinary army of vaccinators who have jabbed like there's no tomorrow".
Vaccines minister Nadhim Zahawi tweeted that the government would "not rest" until the vaccine is offered to all over-50s by the end of April, and then all adults.
The target has been reached in under 10 weeks and one in every four adults was "starting to receive protection from this dreadful disease", said Health Secretary Matt Hancock.
Ministers have been praised for the speed of its vaccine rollout, way ahead of European neighbours.
More than half a million people each day had the jab on Thursday and Friday, with the seven-day average for the first shot running at over 441,000.
Margaret Keenan, 90, was in the media spotlight on 8 December when she became the first person in the world to get the Pfizer vaccine outside of a clinical trial.
The AstraZeneca-Oxford vaccine was also approved on 30 December, helping to dramatically boost the number of shots available.
Last month the programme expanded rapidly to include larger vaccination centres, smaller GP-run centres, as well as some pharmacies and hospitals.
Mosques, museums, rugby grounds and cathedrals are now also among more than 1,500 sites across the country.
From Monday, vaccinations will start on over-65s and more clinically vulnerable people.
Almost 1.2 million letters were due to arrive on Saturday asking people to register for their jabs as part of the next phase of the programme.
People who receive a letter will be able to choose where they receive their vaccine from more than 100 large-scale vaccination centres or almost 200 pharmacy services.
