For all age groups older age of 30.
Of course they didn't say vaccine has negative efficacy for people of 30 or older and no any explanation was given. But from their raw data, It’s almost like the vaccines are fading not to a baseline of zero, but to a point of negative efficacy. UK started vaccine campaign earlier and faster than U.S. So, it's very likely they are ruining out of vaccine efficacy window earlier than us. Besides, UK data is much reliable and transparent than ours.
Give the link of the latest data published.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1025358/Vaccine-surveillance-report-week-41.pdf
You need to downkoad. Then, Check table 2 or figure 2 for data of vaccinated vs unvaccinated. Then use the official vaccine efficacy formula
Efficacy = 1 - vaxxed case rate/ unvaxxed case rate.
to calculate efficacy. You will get negative efficacy for age groups except under 30.
Link: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1025358/Vaccine-surveillance-report-week-41.pdf