However, health officials said that people would be prioritised in age order, with invitations continuing to be issued by age, as they ramp up capacity.
NHS told to ‘prepare for much greater capacity’ in vaccine programme
Vaccines were rolled out to those aged 18 and over in mid June, and 43 million people had their second jab at least three months ago.
Last week, nearly 2.5 million third jabs were administered. If the rollout continued at that pace, it would take until March to give booster injections to all over-18s who come forward.
At the same rate, if would take 10 weeks to administer boosters to all those who are now three months since their second jab.
However, ministers have said they have asked the NHS “to prepare for much greater capacity in our vaccination programme”.
The committee also gave the green light to second jabs for children aged 12 to 15.
Children aged between 12 to 15 are currently only offered one dose of the Covid vaccine.
The precaution was taken because of evidence from other countries linking most cases of myocarditis to second jabs. However, most countries have shorter intervals between doses.
Earlier this month Adam Finn, a member of the JCVI, said the rollout of jabs to adults in Britain – with a gap of between eight and 12 weeks – means there is almost no risk of myocarditis.
The rollout of vaccines to secondary school pupils has been slowed by a change in the guidance, with children who have been infected with Covid told to wait three months before receiving their first jab.
Uncertainty over omicron variant
Professor Jonathan Van-Tam, deputy chief medical officer, said there was currently a “high degree of current uncertainty” about the omicron variant.
He told a Downing Street press conference: “I do not want people to panic at this stage,” saying the current picture was “not all doom and gloom”.
“If vaccine effectiveness is reduced – as seems pretty likely, to some extent – the biggest effects are likely to be in preventing infections and, hopefully, there will be smaller effects in preventing severe disease.
“There are far more things we don’t know yet than things we do know.”
He said those gaps in scientific knowledge would be filled “very rapidly”, as experts around the world work on the problems over the next three weeks.
In South Africa there was also an “elevated growth rate” associated with omicron, although “that is not the same as saying there is definitely an increase in transmissibility” compared with the delta strain.
Professor Wei Shen Lim, chairman of the JCVI, said: “Having a booster dose of the vaccine will help to increase our level of protection against the omicron variant. This is an important way for us to reduce the impact of this variant on our lives, especially in the coming months.
“If you are eligible for a booster, please take up the offer and keep yourself protected as we head into winter.”