Coronavirus vaccines for healthy children are expected to be approved by the UK’s four chief medical officers (CMOs) on Monday.
The CMOs were asked to assess the societal benefit of vaccinating 12-to-15-year-olds, including the impact the pandemic has had on education.
It is expected the advice to ministers will be published later on Monday, sources have told the PA news agency, and the BBC reported the recommendation was to approve rolling out the jabs.
If they give the programme the green light then more than three million children will be eligible for the jab.
The Joint Committee on Vaccination and Immunisation (JCVI) did not recommend mass vaccination of 12 to 15-year-olds.
JCVI experts said that Covid-19 presents a very low risk for healthy children so vaccination would only offer a marginal benefit.
They said the benefit to health was too small to support a universal vaccination programme, but suggested that the Government may wish to take further advice on the issue, including the educational impacts.
The Pfizer and Moderna vaccines are already approved for use among children aged 12 and over by the UK medicines regulator.
But only children with specific health conditions are currently eligible for the jab, as well as those who live in the same house as someone who is immunocompromised.
The JCVI, which made its recommendations at the start of September, also said it had investigated the extremely rare events of inflammation of the heart muscle, known as myocarditis, after Pfizer or Moderna vaccines.
While the condition can result in short periods of hospital observation, followed by typically swift recoveries, the JCVI has concluded the medium to long-term outcomes are still uncertain and more follow-up time is needed to get a clearer picture.
The NHS in England has already been asked to prepare to roll out vaccines for all 12 to 15-year-olds in the event that the CMOs recommend the programme.
Asked about the prospect of vaccinations for 12 to 15-year-olds on a visit to a British Gas training academy, Prime Minister Boris Johnson said: “I think you should really wait and see, wait for what the chief medical officers have to say.
“It’s for them to decide.
“Much better, I think, for them to put out their views, rather than politicians.”
Elsewhere, Professor Neil Ferguson, a member of the Scientific Advisory Group for Emergencies (Sage), said that children should be offered the jab to prevent a winter wave of Covid-19 cases.
The scientist, from Imperial College London, told BBC Radio 4’s Today programme that the UK had been leading in Europe on vaccination until recently but other countries such as Spain, Portugal, France, Italy and Ireland “have got higher vaccination levels than us and that’s largely because they have rolled out vaccination of 12 to 15-year-olds faster than us”.
Prof Ferguson said vaccinating teenagers with a first shot was the priority as the UK looks at dealing with any autumn and winter surges in Covid.
But he said evidence from Israel suggested booster shots for a wider population were “very effective at further driving down transmission and infection”.
Data from the Office for National Statistics show that there are just under 3.2 million children aged 12 to 15 in the UK.