Booster vaccines will be offered to people aged 50 and over, those in care homes and frontline health and social care workers from next week, the government has announced.
Experts said the Pfizer/BioNTech vaccine should be used as the booster dose for more than 30 million people, and that it was safe to be given alongside the usual winter flu jab.
All those who are clinically extremely vulnerable and anyone aged 16 to 65 in an at-risk group group for Covid (who were in priority groups one to nine during the initial vaccine rollout) will also be eligible for a jab.
Three vaccines have been approved as safe and effective as boosters – AstraZeneca, Pfizer and Moderna – but experts have decided to opt for Pfizer as a preference after studies showed it is well tolerated and works well as a booster.
The Pfizer jab as a booster can be given to people who had two doses of AstraZeneca previously.
If necessary, Moderna may be used as an alternative, but as a half-dose booster shot after studies showed it was effective with few side-effects.
People should receive their third booster dose at least six months after they received their second dose of a Covid vaccine.
When there is more data, experts plan to look at whether boosters should also be offered to healthy people under the age of 50.
Professor Wei Shen Lim, chairman of Covid-19 immunisation for the JCVI, said: “The UK’s Covid-19 vaccination programme has been hugely successful in protecting people against hospitalisation and death, and the main aim of the booster programme is to prolong that protection and reduce serious disease as we head towards the colder months.
“The JCVI is advising that a booster dose be offered to the more vulnerable, to maximise individual protection ahead of an unpredictable winter.
“Most of these people will also be eligible for the annual flu vaccine and we strongly advise them to take up this offer as well.”