More than 60 million coronavirus vaccine doses have been given in the UK, the health secretary has announced.
There were 762,361 first or second jabs on Saturday, the second highest daily total of the rollout, and more than 22 million people have now had both doses.
It comes as a study found the Pfizer and AstraZeneca vaccines are highly effective after two doses against the variant identified in India.
The UK Health Security Agency's head urged people to get their second dose.
Dr Jenny Harries said the study was the "first real-world evidence of vaccine effectiveness" against the variant and the "straightforward message" was for people to make sure they took up the offer of the second jab.
But speaking on the BBC's Andrew Marr Show, she urged the public to remain cautious to avoid another lockdown, warning of the threat from the Indian variant which has become the "dominant strain" in some parts of the country.
The latest government data shows 556,951 UK adults received a second jab on Saturday, meaning that 43% of the adult population - 22,643,417 people - have now been fully vaccinated.
Of them 205,410 were first doses, bringing the number of people to have had one dose to 37,943,681 people, or 72% of UK adults.
Only on 20 March, when 844,285 doses were administered, have more jabs been given on a single day. But Saturday's second dose figure surpassed the previous highest daily total of 547,636 set on 24 April.
Another 2,235 new cases and five deaths within 28 days of a positive test have also been announced.
Public Health England, which ran the study into the two vaccines said they are likely to be even more effective at preventing hospital admission and deaths.
Some 13,000 deaths and 39,100 hospitalisations have been prevented in the UK due to the vaccination programme up to 9 May, according to PHE analysis.
Responding to the latest vaccination figures, the health secretary tweeted: "This is a fantastic milestone in our fight against this virus.
"Thank you to everyone involved in our national effort. When you get the call, get the jab."
Earlier Matt Hancock also said the PHE study's findings showed that getting both doses of the vaccine was "absolutely vital".
He added the research made him "increasingly confident" that the government was on track for the final stage of easing restrictions in England on 21 June.
However, Home Secretary Priti Patel said there would not be a "green light all the way", telling the Andrew Marr Show that people have to remain "conscientious.... following all the rules.
"That is part of our normal life now and that will continue, and that, of course, will help us to that unlocking on 21 June."
Appointments for second doses for people in England have been brought forward from 12 to 8 weeks for those in the top nine priority groups.
It follows advice from the Joint Committee on Vaccination and Immunisation, which recommended reducing the interval to counter the threat of new variants.
The variant first discovered in India - also known as B.1.617.2 - is responsible for the majority of new cases in parts of England.
The PHE study found two jabs of either the Pfizer or AstraZeneca vaccine give a similar level of protection against symptomatic disease from the Indian variant as they do for the Kent one.
However, both vaccines were only 33% effective against the Indian variant three weeks after the first dose. This compared with 50% effectiveness against the Kent variant.
The Moderna vaccine has also been used in the UK since April but the study said the numbers who had received it were too small for them to include it in their research.
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