A quarter of young teenagers in England have now had a first dose of Covid-19 vaccine.
An estimated 25.3% of 12 to 15-year-olds had received a jab as of November 3, up from 20.1% a week earlier, Government figures show.
Take-up of vaccines among young teens in England has picked up pace in recent days, after jabs became widely available at vaccination centres across the country.
Previously first doses were being delivered mostly in schools.
Some 45.9% of 12-15 year-olds in Wales are estimated have received a first dose, along with 54.7% in Scotland.
Figures for take-up are calculated slightly differently in the three nations, with England and Wales using age groups based on their national immunisation databases and Scotland using population estimates from the Office for National Statistics.
Vaccines have been available to 12-15 year-olds in Scotland since September 20, and have been delivered mostly at drop-in clinics and other community settings.
The rollout in England also began on September 20, but was initially delivered mainly by NHS teams in schools.
This changed just before the half-term holiday, when parents and children became able to book a jab online at a local vaccination centre.
Take-up in England is also likely to have been affected by the level of infection circulating in the community.
A first dose of vaccine cannot be delivered to someone if they are within four weeks of testing positive for Covid-19, waiting for the results of a coronavirus test, or self-isolating.
Around 9% of children in England in school years seven to 11 were likely to have tested positive for Covid-19 in the week to October 22, the highest rate for any age group, according to estimates from the Office for National Statistics.
Meanwhile there are signs take-up of first doses among young teenagers in Scotland might be slowing, with the latest figure of 54.7% up only slightly from 53.2% a week earlier.
NHS Wales began offering a first dose of vaccine to 12-15-year-olds from October 4.
Most vaccines are being given at vaccination centres with a small number being delivered in schools.
In Northern Ireland, 12 to 15-year-olds are being offered the vaccine in schools but no figures have yet been published on the level of take-up.