The Prime Minister has set a new target of everyone eligible for a booster jab being offered one by the end of January, after 22 cases of the Omicron variant have so far been identified across the UK.
It means 6.9 million over 40s and more than 7 million people aged 18 to 39 will be called up by the NHS for their third vaccination in the next two months.
As of 28 November, 17.9 million people in England had already received a booster or third dose, according to official figures.
While third jabs are now being offered to everyone aged 18 and over, some younger teenagers aged 16 and 17 with underlying health conditions have also been given boosters.
Some 32.8 million over-16s across England do not yet have the protection offered by a third or booster dose, according to analysis of data published by NHS England and population estimates from the Office for National Statistics.
Here we reveal the 10 local authorities in England which have the greatest number of people aged 16 and over not yet vaccinated with a booster or third dose, as of November 21.
1. Birmingham
Birmingham has 703,015 people aged 16 and over who have still not had a booster or a third dose. Photo: JUSTIN TALLIS
2. Leeds
Leeds has 475,260 people aged 16 and over who have still not had a booster or a third dose. Photo: OLI SCARFF
3. Manchester
Manchester has 366,428 people aged 16 and over who have still not had a booster or a third dose. Photo: Anthony Devlin
4. Sheffield
Sheffield has 361,742 people aged 16 and over who have still not had a booster or a third dose. Photo: LINDSEY PARNABY