A UK-wide programme of booster shots to help prevent Covid will be confirmed on Tuesday, the BBC understands.
Ministers are likely to reveal doses for the over-50s as part of their Covid Winter Plan, after advice from the independent vaccine panel, the JCVI.
BBC political editor Laura Kuenssberg said the booster would be a single dose of the Pfizer vaccine at least six months after a second dose.
The NHS began preparing for the booster programme in July.
But the government has been waiting for recommendations from the JVCI on who should receive the extra doses before announcing more details.
Meanwhile, UK chief medical officers have recommended offering one dose of vaccine to healthy 12 to 15-year-olds, saying it would help reduce disruption to education.