The UK government's target of vaccinating two million people a week against coronavirus appears to be on track as more than 324,000 doses were administered in the space of 24 hours.
More than 3.5 million people in the UK have now received their first dose of a vaccine, Prime Minister Boris Johnson said, as he hailed those helping the "fantastic national effort".
The Prime Minister tweeted: "We've given over 3.5 million vaccine doses to protect against COVID-19, with over 324,000 doses yesterday (Friday) alone."
"Thank you to everyone who is helping in this fantastic national effort. Help our NHS by staying at home to save lives."
Ministers are urging the public to "play their part" in supporting the vaccination programme, such as by helping the elderly attend their appointments.
Health Secretary Matt Hancock said people should also sign up to clinical trials for vaccines and treatments, and stay informed with accurate and trusted NHS advice.
"Everyone has a part to play in this national effort - to protect our NHS, our loved ones and other people's loved ones too", he said.
Another 1,295 deaths in the UK were reported on Saturday, the third-highest daily total since the pandemic began, but the lowest number of lab-confirmed cases this year was reported - 41,346.
The figures will be seen as a sign that infections may be levelling off or falling as a result of the lockdown measures, though scientists believe the peak in deaths will come later.
Ten further mass vaccination centres will open in England this week with more than a million over-80s invited to receive their coronavirus jab.
Blackburn Cathedral, St Helens rugby ground, and Norwich Food Court are among the new locations where large-scale vaccination will take place from Monday.
NHS England said they joined the seven existing mass vaccination sites across the country, alongside a thousand GP-led surgeries and more than 250 hospitals already providing jabs.
The UK is preparing to suspend all quarantine-free travel into the UK on Monday in a bid to keep out new coronavirus variants.
The new policy means arrivals from every destination will need to self-isolate for 10 days, or receive a negative result from a coronavirus test taken at least five days after they enter the UK.
Australian Associated Press