When will booster jabs be rolled out?

[Lagirl20]

Just that really. When will booster jabs be rolled out?
The vaccine situation has evolved across the U.K. since the start of this year. Initially vaccines which were in short supply are now being distributed via mass vaccine centres on a weekly basis.
Do you think booster jabs will be given from September at a rapid rate, or will it be more of a slow start, dragging on into the winter months/Christmas?
Any healthcare professionals with intel?

They said it's going to be September for those who were in category 1 and then 2, but the two groups might merge because that has been more efficient to do that.
These are what they've published:
Stage one,
These groups should receive a third vaccine as soon as possible from September:

Adults aged 16 years and over who are immunosuppressed
Those living in residential care homes for older adults
All adults aged 70 years or over
Adults aged 16 years and over who are considered clinically extremely vulnerable
Frontline health and social care workers.

Stage two
These groups should be offered a third dose as soon as practicable after stage one:
All adults aged 50 years and over
Adults aged 16 - 49 years who are in an influenza or Covid at-risk group
Adult household contacts of immunosuppressed individuals.

Wales is saying that if possible it will be extended.

There's no reason why it wouldn't be as efficient as the first vaccine rollout. Winter is our danger period and people won't be as open to not mixing at Christmas.