The UK's National Health Service said that more than half a million people in England have received Pfizer/BioNTech's Covid-19 vaccine.
By December 24, more than 521,000 people had been given the drug after distribution started on December 8.
Statistics from the National Immunisation Management Service showed that more than 70 per cent of recipients were aged 80 or over. Clinically vulnerable groups, such as the elderly and frontline health workers, are first in line for the treatment.
Sixty hospitals and 423 vaccination centres were providing the vaccine from December 8.
Britain is grappling with a new wave of coronavirus.
Authorities reported 39,237 new cases on Wednesday. About 744 new deaths were reported within 28 days of a positive test, the highest since the end of April.
“The rapid rise in cases is hugely worrying,” said Dr Yvonne Doyle, medical director at Public Health England.
On Wednesday, the UK government said more areas of England will enter tier four, with many new cases thought to be caused by a second type of a more infectious Covid-19 strain.
The number of people testing positive for the virus has increased sharply, with about one in 60 people now testing positive in Wales and one in 85 in England, the Office for National Statistics said.
The ONS figures showed that in England an estimated 645,800 people in private households had Covid-19 between December 12 and 18, up from 567,300 from December 6 to 12.
London now has the highest rate of people testing positive, with an estimated 2.1 per cent of people in private households catching the virus.
The ONS estimated that 49 per cent of new cases in England could be a result of the new variant.
Scientists said the mutated coronavirus strain appeared to be more contagious and will probably lead to higher levels of infections and deaths next year.
The variant is 56 per cent more transmissible than other strains, according to the London School of Hygiene and Tropical Medicine. There is no clear evidence that it results in more or less severe disease.
Britain on Wednesday introduced restrictions on travel from South Africa, from where they believe a second mutant variation arrived.
"This new variant is highly concerning because it is yet more transmissible and it appears to have mutated further than the new variant that was discovered in the UK," Health Minister Matt Hancock said.
He said that all individuals in the UK with the variant originating in South Africa had been placed in quarantine, as had their close contacts.
The government is asking anyone who has been in close contact with someone who was in South Africa in the past two weeks to quarantine.
"They must restrict all contact with any other person whatsoever," Mr Hancock said.