Take-up is likely to have been affected by the level of infections across the country.
Less than a third of young adults in many of England’s biggest cities have received a booster or third dose of Covid-19 vaccine, figuras sugerem.
In one local authority, a Londres borough of Barking & Dagenham, the figure is below a quarter, no 23.1%.
Analysis by the PA news agency of data published by NHS England suggests there are 22 local authorities in England where take-up of boosters and third doses among young adults is estimated to be under 33.3%.
They include other large cities such as Bradford (29.9%), Manchester (32.7%) and Leicester (32.8%).
The towns of Luton (28.3%), Burnley (28.6%) and Rochdale (29.9%) are also below the one-third threshold.
The figures are for vaccines delivered up to January 23.
All people aged 18 and over are eligible for a booster if they are three months on from receiving their second dose of vaccine.
Third doses – the other type of extra dose – are available eight weeks after a second dose to people aged 12 and over with severely weakened immune systems.
Take-up of extra doses in recent weeks will have been affected by the level of Covid-19 infections across the country.
People are not able to receive a vaccine within 28 days of having had the virus.
Many double-jabbed adults who had coronavirus in the run-up to Christmas are likely to have only just become eligible for a booster.
Data published on Wednesday by the Office for National Statistics showed that an estimated 2.6 million people in England had Covid-19 in the week ending January 22, down from a record 3.7 million in the week to January 6.
The number of booster and third doses of vaccine delivered across the UK has dropped sharply since the start of the year and currently averages around 60,000 um dia.
This compares with a peak average of nearly 900,000 a day just before Christmas.
The local authorities with the highest estimated take-up of extra doses among 18 to 39-year-olds as of January 23 estão Hart in Hampshire (71.9%), South Oxfordshire (70.8%) and Cotswold in Gloucestershire (69.6%).
The city with the highest estimated take-up is Cambridge, no 68.9%.