Half of all adults in Britain have now received at least one Covid-19 vaccine dose, becoming the world's first major economy to hit that milestone.
Health minister Matt Hancock said on Twitter the figure had been reached after a record 660,276 shots were administered on Friday.
Israel is the leader in vaccinating its population, followed by the United Arab Emirates, Chile and then the United Kingdom - and investors are watching closely to see which economies could recover first.
"The vaccine is a national success story and our way out of this pandemic," said Hancock, adding that he was "delighted".
British Prime Minister Boris Johnson got his first vaccine dose on Friday, receiving AstraZeneca's shot - which several European countries had temporarily stopped using earlier this week over safety fears.
Distributed by the state-run health service, Britain's vaccine roll-out has got off to a blistering start but the government has warned this week of a marked slowdown in April due to a delay of a shipment from India's Serum Institute and because a batch in the UK needed to be retested.
Britain has so far relied on vaccines from AstraZeneca and Oxford University, and Pfizer and BioNTech.