Half of adults in the UK have now had a Covid-19 booster jab, figures show.
It comes after the programme was accelerated this week amid a surge in Covid cases, with online bookings opened up to all adults and walk-in sessions held.
A total of 26.3 million people aged 18 and over have now received a vaccine top-up.
On Twitter, Boris Johnson said: “A record day for vaccinations yesterday with an incredible 936,480 people coming forward.
“That means 50% of adults have now received a booster dose.
“Our NHS is working flat out getting lifesaving booster jabs into arms. Please play your part and Get Boosted Now.”
Booster jabs were given to 861,306 adults on Thursday in total.
The booster vaccine rollout comes as Omicron continues to spread across the UK.
It is now thought to be the dominant variant in both England and Scotland, replacing Delta.
Figures show that confirmed cases of the Omicron variant are doubling every 1.5 days in half of England.
On Friday, the UK reported a record-breaking 93,045 new Covid infections, the highest daily total since the start of the pandemic.
Additional reporting by PA.